Details of the Researcher

PHOTO

Takatoshi Ito
Section
Institute of Fluid Science
Job title
Professor
Degree

  • 博士（工学）（東北大学）

Committee Memberships 28

  • 日本機械学会　東北支部計算力学部門代議員

    2013/04 - Present

  • 日本機械学会　東北支部計算力学部門代議員

    2013/04 - Present

  • 地盤工学会 水圧破砕による初期地圧測定法の基準化検討委員会　委員長

    2012/09 - Present

  • 地盤工学会 水圧破砕による初期地圧測定法の基準化検討委員会　委員長

    2012/09 - Present

  • 資源素材学会 東北支部　常議員

    2012/04 - Present

  • 資源素材学会　代議員

    2012/04 - Present

  • 岩の力学連合会　理事

    2012/04 - Present

  • 資源素材学会 東北支部　常議員

    2012/04 - Present

  • 資源素材学会　代議員

    2012/04 - Present

  • 岩の力学連合会　理事

    2012/04 - Present

  • 岩の力学連合会 国際技術委員会　委員

    2009/08 - Present

  • 岩の力学連合会 国際技術委員会　委員

    2009/08 - Present

  • 土木学会岩盤動力学に関する研究小委員会　委員

    2013/10 - 2015/09

  • 土木学会岩盤動力学に関する研究小委員会　委員

    2013/10 - 2015/09

  • 深田地質研究所 岩盤応力に関する研究委員会　委員

    2012/04 - 2013/03

  • 深田地質研究所 岩盤応力に関する研究委員会　委員

    2012/04 - 2013/03

  • 金沢大学環日本海域環境研究センター 外部評価委員会　委員

    2013/01 - 2013/02

  • 金沢大学環日本海域環境研究センター 外部評価委員会　委員

    2013/01 - 2013/02

  • 第１３回 岩の力学国内シンポジウム　査読委員

    2012/10 - 2012/11

  • 第１３回 岩の力学国内シンポジウム　査読委員

    2012/10 - 2012/11

  • 日本地熱学会湯沢大会現地委員会　委員

    2012/05 - 2012/10

  • 日本地熱学会湯沢大会現地委員会　委員

    2012/05 - 2012/10

  • 深田地質研究所 岩盤応力に関する研究委員会　幹事

    2009/06 - 2012/03

  • 深田地質研究所 岩盤応力に関する研究委員会　幹事

    2009/06 - 2012/03

  • 日本機械学会　校閲委員

    2005/04 - 2010/03

  • 日本機械学会　校閲委員

    2005/04 - 2010/03

  • 日本地熱学会・学会賞選考委員会　委員

    2004/10 - 2008/09

  • 日本地熱学会・学会賞選考委員会　委員

    2004/10 - 2008/09

Show all ︎Show first 5

Professional Memberships 6

  • 米国地球物理学会(American Geophysical Union)NIA

  • 岩の力学連合会

  • 米国地熱学会(Geothermal Resources Council)

  • 日本地熱学会

  • 資源・素材学会

  • 日本機械学会

︎Show all ︎Show first 5

Research Areas 3

  • Natural sciences / Solid earth science / Plysics of Solid Earth

  • Energy / Earth resource engineering, energy science /

  • Manufacturing technology (mechanical, electrical/electronic, chemical engineering) / Machine materials and mechanics /

Awards 5

  1. 2010 Award for Research in Rock Mechanics

    2010/06/28　American Rock Mechanics Association

  2. 岩の力学連合会賞（論文賞）

    2008/06/18　岩の力学連合会

  3. 日本地熱学会論文賞

    2007/11/29　日本地熱学会

  4. 日本機械学会賞 研究奨励賞

    1995/04/01　日本機械学会

  5. (財)機器研究会 研究奨励賞

    1991/01/04　財団法人機器研究会

Papers 136

  1. Creating multidirectional fractures through particle jamming

    Yusuke Mukuhira, Ryota Goto, Noriaki Watanabe, Kazumasa Sueyoshi, Kohei Takuma, Rongchang Zhang, Tongfei Tian, Vladimir Sokolovski, Makoto Naoi, Yuko Arai, Takaaki Tomai, Masaoki Uno, Takatoshi Ito

    International Journal of Rock Mechanics and Mining Sciences　188　106051-106051　2025/04

    Publisher: Elsevier BV

    DOI： 10.1016/j.ijrmms.2025.106051 　

    ISSN： 1365-1609

  2. Stable-to-dynamic expansion of fault slipping area through fluid injection observed in laboratory experiments using a sub-meter scale specimen

    Takatoshi Ito, Koji Aoki, Yusuke Mukuhira, Yasuo Yabe

    Earth, Planets and Space　76　(1)　2024/11/22

    Publisher: Springer Science and Business Media LLC

    DOI： 10.1186/s40623-024-02092-7 　

    eISSN： 1880-5981

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    Abstract In the field, locally applied fluid pressure can initiate fault slip, which may expand unstably over a wide area under certain conditions, generating elastic waves and inducing earthquakes. Therefore, examining the unstable expansion of the initial slip is important. However, reproducing this process in laboratory experiments, such as triaxial loading tests on small cylindrical specimens with inclined faults, is challenging. To achieve this, we prepared a sub-meter-scale cubic specimen, which was separated into two triangular prisms by a model fault. The specimen was subjected to biaxial compression of different magnitudes. A 2D array of strain gauges was embedded beneath the fault plane to measure the changes in shear strain with fault slip driven by fluid injection. Based on the experimental results, we discussed the features of the injection-induced fault slips that lead to earthquakes. The strain increased locally around the edge of the fault slipping area by approximately 10 με, which is equivalent to a shear stress of ~ 0.1 MPa. The fault slipping area first expanded gradually and then unstably beyond the fluid invasion area approximately 3 s after the slip was initiated. The unstable expansion of initial slips was suppressed by reducing the initial shear stress on the fault by 0.3 MPa. In this case, the initial shear stress was possibly too small for additional stress to accumulate at the edge of the fault-slipping area to overcome the static frictional strength of the fault. Our experimental study explicitly confirms that injection-induced aseismic slip can outpace the fluid migration front, finally leading up to a runaway rupture. It also confirms that the level of initial shear stress is important in controlling the rupture size under fluid injection. Graphical Abstract

  3. P–S Travel-Time Detection and Hypocenter Location of Low-SNR Events Using Polarization in the Time–Frequency Domain

    Jingyi Sun, Yusuke Mukuhira, Takayuki Nagata, Taku Nonomura, Michael C. Fehler, Hirokazu Moriya, Nori Nakata, Takatoshi Ito

    Bulletin of the Seismological Society of America　2024/06/07

    Publisher: Seismological Society of America (SSA)

    DOI： 10.1785/0120230280 　

    ISSN： 0037-1106

    eISSN： 1943-3573

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    ABSTRACT The detection of microseismic events with low signal-to-noise ratios (SNRs) can expand the seismic catalog and provide opportunities for a deeper understanding of subsurface reservoir features. We propose a novel polarization analysis method for comprehensively detecting S-wave arrival and P–S travel time of low-SNR events from the particle motion of P and S waves in the time and frequency domain. In most circumstances, the direct S-wave particle motion shows a flat plane, and that is perpendicular to the direct P-wave motion direction. We combine these two properties to detect the S-wave arrival of low-SNR events. Our previous study applied spectral matrix (SPM) analysis to characterize the 3D particle motion of P waves. However, SPM analysis had limitations in detecting S-wave arrivals. We then introduce the time-delay components of the SPM (complex spectral matrix [cSPM]) to characterize the S-wave particle motion, separate the S-wave from the noise, and detect S-wave arrivals. Using the cSPM analysis method, we assess the planarity and perpendicularity of the S-wave polarization in the time and frequency domains. We then define a characteristic function that detects S-wave arrivals by combining two properties, planarity and perpendicularity, to detect more low-SNR events. The P–S travel time is obtained by setting the threshold values for the P- and S-wave characteristic functions. We apply our method to 4 hr and 2 months of field data recorded at the Groningen field in the Netherlands. Our method successfully detects the P–S travel time of all catalog events and several additional undetected events. We locate the hypocenter of all events using the detected P–S travel times with a grid-based search method.

  4. A Trial Evaluation of Rock Core DCDA Absolute Shear Stress Measurement for Routine Quantitative Mining Hazard Assessment in Deep Underground High Stress Mines Peer-reviewed

    Ogasawara, H, Y. Mima, A. Ishida, S. Mngadi, M. Higashi, Y. Yabe, A. Funato, T. Ito, M. Nakatani, R. Durrheim

    Material Transactions　65　817-823　2024/06

    DOI： 10.2320/matertrans.MT-Z2024004 　

  5. On the b-value dependency of injection-induced seismicity on geomechanical parameters

    Y. Mukuhira, M.C. Fehler, E.K. Bjarkason, T. Ito, H. Asanuma

    International Journal of Rock Mechanics and Mining Sciences　174　105631-105631　2024/02

    Publisher: Elsevier BV

    DOI： 10.1016/j.ijrmms.2023.105631 　

    ISSN： 1365-1609

  6. Analysis of large-scale performance with supercritical-water fracturing in geothermal resource development

    Bailong Liu, Anna Suzuki, Deyi Yang, Takatoshi Ito

    Geoenergy Science and Engineering　223　211575-211575　2023/04

    Publisher: Elsevier BV

    DOI： 10.1016/j.geoen.2023.211575 　

    ISSN： 2949-8910

  7. Stress State in the Source Region of Mw2.2 Earthquake in a Deep Gold Mine in South Africa Determined from Borehole Cores

    Yasuo Yabe, Shuhei Abe, Gerhard Hofmann, Dave Roberts, Halil Yilmaz, Hiroshi Ogasawara, Takatoshi Ito, Akio Funato, Masao Nakatani, Makoto Naoi, Raymond Durrheim

    PURE AND APPLIED GEOPHYSICS　2022/04

    DOI： 10.1007/s00024-022-02999-w 　

    ISSN： 0033-4553

    eISSN： 1420-9136

  8. A Trial Evaluation of Rock Core DCDA Absolute Differential Stress Measurement for Routine Quantitative Mining Hazard Assessment in Deep Underground High Stress Mines

    OGASAWARA Hiroshi, MIMA Yoshihiro, ISHIDA Akimasa, MNGADI Siyanda, HIGASHI Mitsuya, YABE Yasuo, FUNATO Akio, ITO Takatoshi, NAKATANI Masao, DURRHEIM Raymond

    Journal of the Society of Materials Science, Japan　71　(3)　259-264　2022/03/15

    Publisher: The Society of Materials Science, Japan

    DOI： 10.2472/jsms.71.259 　

    ISSN： 0514-5163

    eISSN： 1880-7488

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    It is difficult to mine-widely, routinely measure absolute stress in the highly stressed rock mass in deep mines in the world because the drilled holes or cores are damaged during and immediately following the drilling. We evaluate the use of the Diametrical Core Deformation Analysis (DCDA) method, developed by Funato and Ito. The method can evaluate non-destructively the absolute differential stresses and measurement errors in the planes orthogonal to the core axes by precisely measuring the ellipticity of the core section orthogonal to the borehole axis. The five readings required to evaluate a single core take only about ten minutes to make. The measurement system is compact enough for a single regular courier parcel or flight check-in luggage. Absolute differential stresses were determined for thirty-five core samples from fourteen holes in different directions in the highly stressed rock mass in a South African gold mine. We were able to constrain an average 3D differential stress field, consistent with the 3D stress field measured in-situ with an overcoring method, with the maximum principal stress larger than 100 MPa, with a root mean square of residuals of several MPa. Interestingly, the results represent relaxation in shear stress near the fault intersected by the boreholes. The measurements require a core diameter larger than ca. 40 mm, and a core is longer than ca. 10 cm. The method assumes that there is no significant inelastic deformation and that the rock is isotropic.

  9. Fracturing of granite rock with supercritical water for superhot geothermal resources Peer-reviewed

    Bailong Liu, Anna Suzuki, Noriaki Watanabe, Takuya Ishibashi, Kiyotoshi Sakaguchi, Takatoshi Ito

    Renewable Energy　184　56-67　2022/01

    Publisher: Elsevier BV

    DOI： 10.1016/j.renene.2021.11.062 　

    ISSN： 0960-1481

  10. Flow estimation solely from image data through persistent homology analysis Peer-reviewed

    Anna Suzuki, Miyuki Miyazawa, James M. Minto, Takeshi Tsuji, Ippei Obayashi, Yasuaki Hiraoka, Takatoshi Ito

    Scientific Reports　11　(1)　2021/12

    Publisher: Springer Science and Business Media LLC

    DOI： 10.1038/s41598-021-97222-6 　

    eISSN： 2045-2322

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    <title>Abstract</title>Topological data analysis is an emerging concept of data analysis for characterizing shapes. A state-of-the-art tool in topological data analysis is persistent homology, which is expected to summarize quantified topological and geometric features. Although persistent homology is useful for revealing the topological and geometric information, it is difficult to interpret the parameters of persistent homology themselves and difficult to directly relate the parameters to physical properties. In this study, we focus on connectivity and apertures of flow channels detected from persistent homology analysis. We propose a method to estimate permeability in fracture networks from parameters of persistent homology. Synthetic 3D fracture network patterns and their direct flow simulations are used for the validation. The results suggest that the persistent homology can estimate fluid flow in fracture network based on the image data. This method can easily derive the flow phenomena based on the information of the structure.

  11. Injection-Induced Seismicity Size Distribution Dependent on Shear Stress Peer-reviewed

    Y. Mukuhira, M. C. Fehler, T. Ito, H. Asanuma, M. O. Häring

    Geophysical Research Letters　48　(8)　2021/04

    Publisher: American Geophysical Union (AGU)

    DOI： 10.1029/2020GL090934 　

    ISSN： 0094-8276

    eISSN： 1944-8007

  12. Inferring fracture forming processes by characterizing fracture network patterns with persistent homology Peer-reviewed

    A. Suzuki, M. Miyazawa, A. Okamoto, H. Shimizu, I. Obayashi, Y. Hiraoka, T. Tsuji, P.K. Kang, T. Ito

    Computers & Geosciences　143　104550-104550　2020/10

    Publisher: Elsevier BV

    DOI： 10.1016/j.cageo.2020.104550 　

    ISSN： 0098-3004

  13. Evaluation of flow paths during stimulation in an EGS reservoir using microseismic information Peer-reviewed

    Yusuke Mukuhira, Takatoshi Ito, Hiroshi Asanuma, Markus Haring

    GEOTHERMICS　87　2020/09

    DOI： 10.1016/j.geothermics.2020.101843 　

    ISSN： 0375-6505

    eISSN： 1879-3576

  14. Numerical analysis of different fracturing mechanisms between supercritical CO2 and water-based fracturing fluids Peer-reviewed

    Bailong Liu, Anna Suzuki, Takatoshi Ito

    INTERNATIONAL JOURNAL OF ROCK MECHANICS AND MINING SCIENCES　132　2020/08

    DOI： 10.1016/j.ijrmms.2020.104385 　

    ISSN： 1365-1609

    eISSN： 1873-4545

  15. Experimental Study on Nano-/Microparticles Transport to Characterize Structures in Fractured Porous Media Peer-reviewed

    Anna Suzuki, Junzhe Cui, Yuran Zhang, Satoshi Uehara, Kewen Li, Roland N. Horne, Takatoshi Ito

    ROCK MECHANICS AND ROCK ENGINEERING　2020/03

    DOI： 10.1007/s00603-020-02081-8 　

    ISSN： 0723-2632

    eISSN： 1434-453X

  16. Impact of fluid pressure on failure mode in shear zones: Numerical simulation of en-echelon tensile fracturing and transition to shear Peer-reviewed

    Atsushi Okamoto, Kazumasa Fuse, Hiroyuki Shimizu, Takatoshi Ito

    Tectonophysics　774　2020/01/05

    DOI： 10.1016/j.tecto.2019.228277 　

    ISSN： 0040-1951

  17. Experimental verification of the dual bit coring method developed for stress measurement applicable in deep and high temperature environment

    T. Ito, A. Kumazawa, K. Tezuka, T. Yokoyama, K. Ogawa, A. Funato

    54th U.S. Rock Mechanics/Geomechanics Symposium　2020

  18. First field test of the dual core-bit tool for drilling stress record cores at Kamioka mine, Japan Peer-reviewed

    Kazuhiko Tezuka, Toshiya Yamamoto, Takatoshi Ito, Tatsuya Yokoyama, Akio Funato

    SPWLA 25th Formation Evaluation Symposium of Japan, JFES 2019　2020

  19. Estimating the seepage effect of SC-CO2 and water fracturing with a steady-state flow model considering capillary and viscous forces at the pore scale Peer-reviewed

    Bailong Liu, Anna Suzuki, Takatoshi Ito

    JOURNAL OF PETROLEUM SCIENCE AND ENGINEERING　184　2020/01

    DOI： 10.1016/j.petrol.2019.106483 　

    ISSN： 0920-4105

    eISSN： 1873-4715

  20. Introduction of natural fracture information to induced seismicity analysis Peer-reviewed

    Y. Mukuhira, M. Ziegler, T. Ito, H. Asanuma, M.O. Häring

    Proc. YSRM2019 & REIF 2019　2019/12

  21. In-situ stress constraints on the focal mechanisms of induced seismicity Peer-reviewed

    Y. Mukuhira, T. Ito, M.C. Fehler, M. Naoi, H. Moriya, H. Asanuma, M. O. Häring

    Proc. ISRM2019　2019/09

  22. [Keynote lecture] Spatial variation in stress in seismogenic zones in South African gold mines

    Ogasawara, H, A. Ishida, K. Sugimura, Y. Yabe, S. Abe, T. Ito, A. Funato, H. Kato, B. Liebenberg, G. Hofmann, L. Scheepers, R. J. Durrheim, the SATREPS, DSeis teams

    Proceedings of the 2019 Rock Dynamics Summit in Okinawa, A specialized conference of ISRM　39-44-44　2019/05

    DOI： 10.1201/9780429327933-5 　

  23. Rock stresses around active faults measured by using the high stiffness hydraulic fracturing technique, in Ö. AYDAN, T. SEIKI, K. KAMEMURA, N. IWATA, T. ITO Litvinenko (Ed.)

    Yokoyama, T, Murakami, M, Danjo, T, Ogawa, K, Lin, A, Lin, W, Ito, T

    Proceedings of 2019 Rock Dynamics Summit in Okinawa　616-621　2019/05

  24. Rock stresses around active faults measured by using the high stiffness hydraulic fracturing technique

    T. Yokoyama, M. Murakami, T. Danjo, K. Ogawa, A. Lin, W. Lin, T. Ito

    Rock Dynamics Summit - Proceedings of the 2019 Rock Dynamics Summit, RDS 2019　638-643　2019

    DOI： 10.1201/9780429327933-103 　

  25. Experimental study of tip screenout fracturing by using CT scanner Peer-reviewed

    T. Ito, H. Yoshida, K. Yamamoto, Y. Tsuchiya

    53rd U.S. Rock Mechanics/Geomechanics Symposium　2019

  26. Effect of capillary force on performance of shale rock fracturing Peer-reviewed

    B. L. Liu, A. Suzuki, T. Ito

    53rd U.S. Rock Mechanics/Geomechanics Symposium　2019

  27. ICDP DSeis Project 南アフリカ金鉱山マグニチュード2〜5.5の地震発生場の掘削に成功！？

    小笠原宏, 矢部康男, 伊藤高敏, 廣野哲朗

    J-DESCニュースレター　9　14　2018/05

  28. A new method of stress measurement based on elastic deformation of sidewall-core with stress relief during coring Peer-reviewed

    T. Ito, S. Fukusawa, A. Funato, T. Tamagawa, K. Tezuka

    52nd U.S. Rock Mechanics/Geomechanics Symposium　2018

  29. A study of the effect of brittleness on hydraulic fracture complexity using a flow-coupled discrete element method Peer-reviewed

    Hiroyuki Shimizu, Takatoshi Ito, Tetsuya Tamagawa, Kazuhiko Tezuka

    Journal of Petroleum Science and Engineering　160　372-383　2018/01

    DOI： 10.1016/j.petrol.2017.10.064 　

    ISSN： 0920-4105

  30. Hybrid focal mechanism determination: Constraining focal mechanisms of injection induced seismicity using in situ stress data Peer-reviewed

    Y. Mukuhira, K. Fuse, M. Naoi, M. C. Fehler, H. Moriya, T. Ito, H. Asanuma, M. O. Häring

    Geophysical Journal International　215　(2)　1427-1441　2018

    DOI： 10.1093/GJI/GGY333 　

    ISSN： 0956-540X

    eISSN： 1365-246X

  31. メタンハイドレート開発を目的とした未固結砂層のフラクチャリングに関する基礎研究 Peer-reviewed

    伊藤高敏, 天満則夫

    石油技術協会誌　83　(6)　491-498　2018

  32. Status of Japanese Supercritical Geothermal Project as of FY2017 Peer-reviewed

    Asanuma,.H, Mogi, T, Tsuchiya, N, Watanabe,. N, Naganawa, S, Ogawa, Y, Fujimitsu, Y, Kajiwara, T, Osato, K, Shimada, K, Horimoto, S, Sato, T, Ito, T, Yamada, S, Watanabe, K, Gotoh, Y, Nagasawa, Y, Kohyama, A

    Geothermal Resources Council Transactions　42　2018

  33. Pore pressure migration during hydraulic stimulation due to permeability enhancement by low-pressure subcritical fracture slip Peer-reviewed

    Yusuke Mukuhira, Hirokazu Moriya, Takatoshi Ito, Hiroshi Asanuma, Markus Haring

    GEOPHYSICAL RESEARCH LETTERS　44　(7)　3109-3118　2017/04

    DOI： 10.1002/2017GL072809 　

    ISSN： 0094-8276

    eISSN： 1944-8007

  34. Estimate of the stress state of earthquake source region in a South African deep gold mining by diametrical core deformation analysis (DCDA)

    Shuhei ABE, Yasuo YABE, Takatoshi ITO, Masao NAKATANI, Gerhard, HOFMANN, Hiroshi OGASAWARA

    Proceedings of the 14th Symposium of Japan Rock Mechanics Society.　(講演番号107)　1-6　2017/01

  35. Drilling into seismogenic zones of M2.0 – M5.5 earthquakes from deep South African gold mines (DSeis): establishment of research sites Peer-reviewed

    H. Ogasawara, R. J. Durrheim, Y. Yabe, T. Ito, G. van Aswegen, M. Grobbelaar, A. Funato, A. Ishida, H. Ogasawara, S. Mngadi, M. S.D. Manzi, M. Ziegler, A. K. Ward, G. Hofmann, P. Moyer, M. Boettcher, P. Dight, W. Ellsworth, B. Liebenberg, N. Wechsler, T. Onstott, N. Berset

    ISRM AfriRock - Rock Mechanics for Africa　2017-October　237-248　2017

  36. Elastic deformation of core sample with stress relief by drilling and its application to rock stress estimation Peer-reviewed

    Takatoshi Ito, Akio Funato, Tetsuya Tamagawa, Kazuhiko Tezuka

    23rd Formation Evaluation Symposium of Japan 2017　2017

  37. Re-Opening and Shut-in Behaviors under a Large Ratio of Principal Stresses in a Hydraulic Fracturing Test Peer-reviewed

    Tatsuya Yokoyama, Kiyotoshi Sakaguchi, Takatoshi Ito

    Procedia Engineering　191　862-868　2017

    DOI： 10.1016/j.proeng.2017.05.254 　

    eISSN： 1877-7058

  38. A new method of diametrical core deformation analysis for in-situ stress measurements Peer-reviewed

    Akio Funato, Takatoshi Ito

    INTERNATIONAL JOURNAL OF ROCK MECHANICS AND MINING SCIENCES　91　112-118　2017/01

    DOI： 10.1016/j.ijrmms.2016.11.002 　

    ISSN： 1365-1609

    eISSN： 1873-4545

  39. Pore pressure behavior at the shut-in phase and causality of large induced seismicity at Basel, Switzerland Peer-reviewed

    Y. Mukuhira, C. Dinske, H. Asanuma, T. Ito, M. O. Häring

    Journal of Geophysical Research: Solid Earth　122　(1)　411-435　2017/01/01

    DOI： 10.1002/2016JB013338 　

    ISSN： 2169-9313

    eISSN： 2169-9356

  40. Distribution of stress state in the Nankai subduction zone, southwest Japan and a comparison with Japan Trench Peer-reviewed

    Weiren Lin, Timothy B. Byrne, Masataka Kinoshita, Lisa C. McNeill, Chandong Chang, Jonathan C. Lewis, Yuzuru Yamamoto, Demian M. Saffer, J. Casey Moore, Hung-Yu Wu, Takeshi Tsuji, Yasuhiro Yamada, Marianne Conin, Saneatsu Saito, Takatoshi Ito, Harold J. Tobin, Gaku Kimura, Kyuichi Kanagawa, Juichiro Ashi, Michael B. Underwood, Toshiya Kanamatsu

    TECTONOPHYSICS　692　120-130　2016/12

    DOI： 10.1016/j.tecto.2015.05.008 　

    ISSN： 0040-1951

    eISSN： 1879-3266

  41. Physics-based seismic evaluation method: Evaluating possible seismic moment based on microseismic information due to fluid stimulation Peer-reviewed

    Yusuke Mukuhira, Hiroshi Asanuma, Takatoshi Ito, Markus O. Haring

    GEOPHYSICS　81　(6)　KS195-KS205　2016/11

    DOI： 10.1190/GEO2015-0648.1 　

    ISSN： 0016-8033

    eISSN： 1942-2156

  42. Development of the deep rock stress tester Peer-reviewed

    Takatoshi Ito, Toshiyuki Nayuki, Kazumasa Kalo, Akio Funalo, Takashi Satoh, Yuichi Kitagawa, Harumi Kato

    ISRM International Symposium on In-Situ Rock Stress, ISRS 2016　2016-May　376-384　2016

  43. Stress state analysis of a fault plane with large induced seismicity Peer-reviewed

    Y. Mukuhira, T. Ito, H. Asanuma, M. Haring

    50th US Rock Mechanics / Geomechanics Symposium 2016　4　3287-3293　2016

  44. X線CT を利用した未固結砂層の破壊と出砂の室内実験 Peer-reviewed

    松原 大樹, 伊藤 高敏, 長野 優羽

    Journal of the Japanese Association for Petroleum Technology　80　(5)　410-411　2015/09

  45. Flow-coupled DEM modeling for hydraulic fracturing in unconsolidated sands Peer-reviewed

    H. Shimizu, M. Shazree, T. Ito, H. Narita

    Computer Methods and Recent Advances in Geomechanics - Proceedings of the 14th Int. Conference of International Association for Computer Methods and Recent Advances in Geomechanics, IACMAG 2014　1697-1701　2015

  46. Development of experimental apparatus for real-time observation of hydraulic fracture in unconsolidated sands by x-ray CT method Peer-reviewed

    T. Ito, Y. Nagano

    49th US Rock Mechanics / Geomechanics Symposium 2015　2　1595-1603　2015

  47. コア変形法（DCDA）の室内検証実験 Peer-reviewed

    船戸明雄, 伊藤高敏, 三上 央

    Journal of MMIJ　130　(12)　515-521　2014/12

    DOI： 10.2473/journalofmmij.130.515 　

  48. Comprehensive evaluation of the initial rock stress carried out as part of a 2000m all core borehole investigation Peer-reviewed

    T. Nayuki, K. Ando, K. Onishi, N. Nishizaka, Y. Ishikawa, Y. Ohno, S. Kato, T. Ito

    ISRM International Symposium - 8th Asian Rock Mechanics Symposium, ARMS 2014　2215-2223　2014

  49. Flow-coupled DEM simulation for hydraulic fracturing in pre-fractured rock Peer-reviewed

    H. Shimizu, M. Hiyama, T. Ito, T. Tamagawa, K. Tezuka

    48th US Rock Mechanics / Geomechanics Symposium 2014　1　715-721　2014

  50. Real-time observation of hydraulic fracture growth in soft rocks under confining stress using X-ray CT Peer-reviewed

    T. Ito, Y. Omori, Y. Nagano

    ISRM International Symposium - 8th Asian Rock Mechanics Symposium, ARMS 2014　1632-1637　2014

  51. Laboratory study for pore water effect on hydraulically-induced fracture behavior in unconsolidated sands Peer-reviewed

    T. Ito, H. Narita

    48th US Rock Mechanics / Geomechanics Symposium 2014　2　834-838　2014

  52. Possibility to remedy CO<inf>2</inf> leakage from geological reservoir using CO<inf>2</inf> reactive grout Peer-reviewed

    Takatoshi Ito, Tianfu Xu, Hidenori Tanaka, Yuhki Taniuchi, Atsushi Okamoto

    International Journal of Greenhouse Gas Control　20　310-323　2014/01

    DOI： 10.1016/j.ijggc.2013.11.014 　

    ISSN： 1750-5836

  53. The Japan beyond-brittle project Peer-reviewed

    H. Muraoka, H. Asanuma, N. Tsuchiya, T. Ito, T. Mogi, H. Ito

    Scientific Drilling　17　(17)　51-59　2014

    DOI： 10.5194/sd-17-51-2014 　

    ISSN： 1816-8957

    eISSN： 1816-3459

  54. Numerical thermo-elastic simulation for change in fracture aperture associated with cold fluid injection Peer-reviewed

    Kosuke Kaneta, Yusuke Mukuhira, Takatoshi Ito

    Transactions - Geothermal Resources Council　38　301-304　2014

    ISSN： 0193-5933

  55. Diametrical Core Deformation Analysis (DCDA) Developed for In-situ Rock Stress Measurements

    FUNATO Akio, ITO Takatoshi

    Shigen-to-Sozai　129　(8)　577-584　2013/08/01

    Publisher: The Mining and Materials Processing Institute of Japan

    DOI： 10.2473/journalofmmij.129.577 　

    ISSN： 1881-6118

    More details Close

    DCDA is a new method for evaluating the in-situ stress of rocks based on the elliptical deformation of boring cores with stress relief. When a rock core sample is carved out by drilling, it becomes free from in-situ stress, and the expansion should occur elastically. If the condition of in-situ stress is anisotropic, the core must deform in an asymmetric manner. With the precise measurement of core diameters in each directions, the deviatoric stress SHmax <tt>－</tt>Shmin and azimuths of SHmax and Shmin could be determined from the circumferential variation of the measured diameter. In order to confirm the reliability of DCDA, laboratory verifications were conducted. The estimated stresses by DCDA agreed well with the applied stresses, and the directions of dmax coincide to the directions of the applied stresses. From these results, the effectiveness of DCDA was confirmed.

  56. In situ stress and pore pressure in the kumano forearc basin, offshore SW Honshu from downhole measurements during riser drilling Peer-reviewed

    D. M. Saffer, P. B. Flemings, D. Boutt, M. L. Doan, T. Ito, L. McNeill, T. Byrne, M. Conin, W. Lin, Y. Kano, E. Araki, N. Eguchi, S. Toczko

    Geochemistry, Geophysics, Geosystems　14　(5)　1454-1470　2013/05/01

    DOI： 10.1002/ggge.20051 　

    eISSN： 1525-2027

  57. ボアホールブレイクアウトに対する中間主応力の影響の実験的検討 Peer-reviewed

    青柳和平, 石田 毅, 村田澄彦, 山本晃司, 関根孝太郎, 伊藤高敏, 陳 渠

    Journal of MMIJ　129　(4)　107-115　2013/04

    Publisher: The Mining and Materials Processing Institute of Japan

    DOI： 10.2473/journalofmmij.129.107 　

    ISSN： 1881-6118

    More details Close

    Borehole breakout, which is shear failure of the borehole wall, is one of the serious problems in drilling wells for oil/gas exploration and production. Investigation of stress condition causing breakout helps to avoid this problem. Conventionally, simple failure criteria, such as Mohr-Coulomb, which disregard the effect of the intermediate principal stress, were used to evaluate the stress condition. However, many researchers have reported that the intermediate principal stress affects the stress condition causing breakout. In this paper, the authors conducted true triaxial experiments using cubic rock specimens with a borehole to investigate the effect of the intermediate principal stress. In these experiments, measurements of tangential strains around the borehole wall and a weight of failed rock fragments by the scale, and observation of the wall using video camera were conducted to detect the failure development process. The effect of the intermediate principal stress was evaluated in five points along failure development detected by the measurements and the observations described above. The experimental results elucidated that the magnitudes of stress causing breakout clearly increase with increase of the intermediate principal stress in the all points along the failure development. However, when the authors compared the results with the three failure criteria, Modified-Lade, Drucker-Prager and Mogi, which consider the effect of the intermediate principal stress, the three failure criteria underestimated the stress condition causing breakout.

  58. Determination of stress state in deep subsea formation by combination of hydraulic fracturing in situ test and core analysis: A case study in the IODP Expedition 319 Peer-reviewed

    Takatoshi Ito, Akio Funato, Weiren Lin, Mai-Linh Doan, David F. Boutt, Yasuyuki Kano, Hisao Ito, Demian Saffer, Lisa C. McNeill, Timothy Byrne, Kyaw Thu Moe

    JOURNAL OF GEOPHYSICAL RESEARCH-SOLID EARTH　118　(3)　1203-1215　2013/03

    DOI： 10.1002/jgrb.50086 　

    ISSN： 2169-9313

    eISSN： 2169-9356

  59. 海底浅部地層を模擬した試験片によるフラクチャリング室内実験 Peer-reviewed

    伊藤高敏, 大森康雅, 成田英夫

    第１３回岩の力学国内シンポジウム講演論文集　1　371-375　2013/01

  60. Distinct element analysis for hydraulic fracturing in shale - Effect of brittleness on the fracture propagation Peer-reviewed

    Michiharu Hiyama, Hiroyuki Shimizu, Takatoshi Ito, Tetsuya Tamagawa, Kazuhiko Tezuka

    47th US Rock Mechanics / Geomechanics Symposium 2013　2　1405-1412　2013

  61. Experimental study of hydraulic fracturing in unconsolidated sands using X-ray CT method Peer-reviewed

    Y. Omori, S. Jin, T. Ito, Y. Nagano, K. Sekine

    47th US Rock Mechanics / Geomechanics Symposium 2013　3　1974-1980　2013

  62. Operational review of the first wireline in situ stress test in scientific ocean drilling Peer-reviewed

    Moe Kyaw Thu, Takatoshi Ito, Weiren Lin, Mai Linh Doan, David Boutt, Yoshihisa Kawamura, Chee Kin Khong, Lisa McNeill, Timothy Byrne, Demian Saffer, Eiichiro Araki, Nobu Eguchi, Ikuo Sawada, Peter Flemings, Yasuyuki Kano, Casey Moore, Masataka Kinoshita, Harold Tobin

    Scientific Drilling　(13)　35-39　2012/04

    DOI： 10.2204/iodp.sd.13.06.2011 　

    ISSN： 1816-8957

    eISSN： 1816-3459

  63. Scale dependence of in-situ permeability measurements in the Nankai accretionary prism: The role of fractures Peer-reviewed

    David F. Boutt, Demian Saffer, Mai-Linh Doan, Weiren Lin, Takatoshi Ito, Yasuyuki Kano, Peter Flemings, Lisa C. McNeill, Timothy Byrne, Nicholas W. Hayman, Kyaw Thu Moe

    GEOPHYSICAL RESEARCH LETTERS　39　(7)　2012/04

    DOI： 10.1029/2012GL051216 　

    ISSN： 0094-8276

    eISSN： 1944-8007

  64. Stress State at the Expedition 319 Drilling Site Estimated from Hydrofracturing Data and Core Deformation Taking account of the System Compliance Effect

    T. Ito, A. Funato, H. Ito

    Abstract Book for International Conference on a New Perspective of Great Earthquake along Subduction Zone　2012/02/28

  65. A new laboratory test for shear fracture formation and its permeability measurement Peer-reviewed

    T. Ito, T. Shono, K. Sekine, K. Yamamoto

    Harmonising Rock Engineering and the Environment - Proceedings of the 12th ISRM International Congress on Rock Mechanics　645-648　2012

  66. Laboratory verification of the Diametrical Core Deformation Analysis (DCDA) developed for in-situ stress measurements Peer-reviewed

    Akio Funato, Takatoshi Ito, Taito Shono

    46th US Rock Mechanics / Geomechanics Symposium 2012　2　1407-1412　2012

  67. The distinct element analysis for hydraulic fracturing in unconsolidated sand considering fluid viscosity Peer-reviewed

    Hiroyuki Shimizu, Sumihiko Murata, Takatoshi Ito, Tsuyoshi Ishida

    ISRM Regional Symposium - 7th Asian Rock Mechanics Symposium, ARMS 2012　806-813　2012

  68. Challenges to stress measurements in deep and/or unconsolidated rock formations for frontier rock engineering Peer-reviewed

    Takatoshi Ito

    ISRM Regional Symposium - 7th Asian Rock Mechanics Symposium, ARMS 2012　19-25　2012

  69. Effect of anisotropic confining stresses on hydraulically-induced fracture propagation from perforated cased-hole in unconsolidated sands Peer-reviewed

    T. Ito, K. Yamamoto, S. Nagakubo

    45th US Rock Mechanics / Geomechanics Symposium　2011

  70. 未固結砂層のフラクチャリング挙動を模擬する室内実験 Peer-reviewed

    伊藤高敏, 五十嵐哲, 山本晃司

    Journal of MMIJ　127　(6,7)　243-248　2011

    Publisher: The Mining and Materials Processing Institute of Japan

    DOI： 10.2473/journalofmmij.127.243 　

    ISSN： 1881-6118

    More details Close

    In order to clarify fracture initiation and propagation in unconsolidated sand, we carried out hydraulic fracturing tests in laboratory focusing on moderate-permeability sand. Silica sand with particle size of about 100 μm has been generally used as the simulated formation materials in laboratory fracturing experiments. Permeability of such sand is high in the order of few darcy. Thus we mixed finer particles of kaolinite with sand, and finally succeeded to prepare the mixture of sand and kaolinite with permeability of about 5 mD. We layered the mixture in a mold to form a cubical specimen of 200 x 200 x 200 mm3. At fracturing tests, the specimen was set in a loading frame of a newly-developed test system. Tri-axial compressive stresses of 2∼3 MPa were applied to the specimen. Fracturing fluid of a machine oil with viscosity of 300 cP was pumped by a constant rate of 10∼100 mL / min into a simulated borehole of a steel pipe which was buried vertically in the specimen, and then the fluid flew out inside the specimen passing through the slit of the steel pipe. After the tests, we excavated the specimen bit by bit and observed how the fracturing fluid invaded into the specimen. <BR>The laboratory tests demonstrated that fracture-like parting / fracture formation at macro scale was induced in the specimen by fluid injection. During fracture propagation, the pore pressure in the vicinity ahead of fracture tip seemed to increase due to fluid invasion. Fracture patters were obviously changed with injection flow rate. Lower injection flow rate led to a single and straight fracture and higher injection rate led to branching fractures, while in all cases, overall alignment of fractures was in the direction of the maximum horizontal compressive stress. Such phenomena are different from those observed in competent rocks.

  71. Present-day principal horizontal stress orientations in the Kumano forearc basin of the southwest Japan subduction zone determined from IODP NanTroSEIZE drilling Site C0009 Peer-reviewed

    Weiren Lin, Mai-Linh Doan, J. Casey Moore, Lisa McNeill, Timothy B. Byrne, Takatoshi Ito, Demian Saffer, Marianne Conin, Masataka Kinoshita, Yoshinori Sanada, Kyaw Thu Moe, Eiichiro Araki, Harold Tobin, David Boutt, Yasuyuki Kano, Nicholas W. Hayman, Peter Flemings, Gary J. Huftile, Deniz Cukur, Christophe Buret, Anja M. Schleicher, Natalia Efimenko, Kuniyo Kawabata, David M. Buchs, Shijun Jiang, Koji Kameo, Keika Horiguchi, Thomas Wiersberg, Achim Kopf, Kazuya Kitada, Nobuhisa Eguchi, Sean Toczko, Kyoma Takahashi, Yukari Kido

    GEOPHYSICAL RESEARCH LETTERS　37　(L13303)　2010/07

    DOI： 10.1029/2010GL043158 　

    ISSN： 0094-8276

    eISSN： 1944-8007

  72. Proposed Concept of In-situ Reaction Barrier to Remedy Leakage from Reservoirs of Geological CO2 Storage Invited

    T.Ito

    Proc. of the 2nd International Symposium of Experimental-Integrated Computational Chemistry on Multiscale Fluidics　1　55-56　2010/02/24

  73. Dynamic monitoring of fracture extension in unconsolidated sand specimen by GPR Peer-reviewed

    Dong Hun Kim, Motoyuki Sato, Takatoshi Ito

    Proceedings of the 13th Internarional Conference on Ground Penetrating Radar, GPR 2010　2010

    DOI： 10.1109/ICGPR.2010.5550158 　

  74. Deep rock stress measurement by hydraulic fracturing method taking account of system compliance effect Peer-reviewed

    T. Ito, T. Satoh, H. Kato

    Rock Stress and Earthquakes - Proceedings of the 5th International Symposium on In-Situ Rock Stress　1　43-49　2010

  75. Laboratory Test of Hydraulic Fracturing in Unconsolidated Deformable Rocks Peer-reviewed

    T. Ito, A. Igarashi, K. Yamamoto

    PORO-MECHANICS IV　1001-+　2009

  76. Effect of pore pressure gradient on fracture initiation in fluid saturated porous media: Rock Invited Peer-reviewed

    Takatoshi Ito

    ENGINEERING FRACTURE MECHANICS　75　(7)　1753-1762　2008/05

    DOI： 10.1016/j.engfracmech.2007.03.028 　

    ISSN： 0013-7944

  77. Numerical simulation of supercritical CO2 injection into subsurface rock masses Peer-reviewed

    Kenta Sasaki, Takashi Fujii, Yuichi Nilbori, Takatoshi Ito, Toshiyuki Hashida

    ENERGY CONVERSION AND MANAGEMENT　49　(1)　54-61　2008/01

    DOI： 10.1016/j.enconman.2007.05.015 　

    ISSN： 0196-8904

  78. Detection of Flow-pathway Structure based on Pore Pressure Distribution Estimated from Microseismic Events Peer-reviewed

    Takatoshi Ito, Kazuo Hayashi, Kazuyoshi Osada, Roy Baria

    Journal of the Geothermal Research Society of Japan　30　(1)　49-60　2008

    DOI： 10.11367/grsj1979.30.49 　

    ISSN： 1883-5775 0388-6735

  79. Renewable Geo-energy Development at Practical Srage Invited Peer-reviewed

    Takatoshi ITO, Yuichi NIIBORI

    Journal of the Heat Transfer Society of Japan　46　(196)　28-37　2007/07

  80. High-resolution aftershock observations in the source region of the 2004 mid-Niigata Prefecture Earthquake Peer-reviewed

    Aitaro Kato, Masakatsu Arao, Keisuke Ariyoshi, Youichi Asano, Keiji Doi, Bogdan Enescu, Shinya Fujieda, Hiroko Hagiwara, Toshio Haneda, Akira Hasegawa, Shin'ichi Hashimoto, Satoshi Hirahara, Naoshi Hirata, Yasuhiro Hirata, Issei Hirose, Shusaku Hondo, Kumiko Hori, Shuichiro Hori, Shigeki Horiuchi, Toshihiko Igarashi, Takashi Iidaka, Yoshihisa Iio, Ryoya Ikuta, Takeo Ito, Takaya Iwasaki, Aya Kamimura, Toshihiko Kanazawa, Yasuyuki Kano, Hiroshi Katao, Satoshi Kawamoto, Tomonori Kawamura, Saeko Kita, Masaru Kobayashi, Yuhki Kohno, Toshio Kono, Masahiro Kosuga, Atsuki Kubo, Eiji Kurashimo, Satoshi Matsumoto, Takeshi Matsushima, Toru Matsuzawa, Noa Mitsui, Reiko Miura, Masatoshi Miyazawa, Tomoko Mizukami, Satoko Murotani, Satoru Nagai, Junichi Nakajima, Takashi Nakayama, Hiroaki Negishi, Kinya Nishigami, Izumi Ogino, Shiro Ohmi, Tomomi Okada, Hiroki Onaha, Shantha S.N. Gamage, Mamoru Saka, Shin'ichi Sakai, Katsuhito Sato, Toshiya Sato, Masato Serizawa, Takuo Shibutani, Junpei Shimizu, Junichi Suganomata, Kiyoko Tagami, Keisuke Takahashi, Kaori Takai, Fumiaki Takeuchi, Yasuda Takumi, Kazuo Tanaka, Ken'ichi Tatsumi, Takashi Tonegawa, Hiroaki Tsushima, Naoki Uchida, Kenji Uehira, Tomotake Ueno, Norihito Umino, Hiroo Wada, Kazutoshi Watanabe, Shigeru Watanabe, Yasuo Yabe, Tadashi Yaginuma, Mamoru Yamada, Shunroku Yamamoto, Yoshiko Yamanaka, Futoshi Yamashita, Fumihito Yamazaki, Satoshi Yui, Yohei Yukutake

    Earth, Planets and Space　59　(8)　923-928　2007

    DOI： 10.1186/BF03352030 　

    ISSN： 1343-8832

    eISSN： 1880-5981

  81. Numerical simulation of injection for CO2 geological sequestration with a treatment of CO2 dissolution into water Peer-reviewed

    K. Sasaki, T. Fujii, Y. Niibori, T. Ito, T. Hashida

    WATER DYNAMICS　898　45-+　2007

    DOI： 10.1063/1.2721247 　

    ISSN： 0094-243X

  82. On Reliability of Stress Determined by Hydraulic Fracturing Stress Measurement Using Transverse Fractures Peer-reviewed

    Hayashi, K, Sato, A, Ito, T

    Geother. Resour. Coun. Trans.　31　285-290　2007

  83. BABHY-A new strategy of hydrofracturing for deep stress measurements Peer-reviewed

    Takatoshi Ito, Kentaro Omura, Hisao Ito

    Scientific Drilling　Special Issue　(1)　113-116　2007

    DOI： 10.2204/iodp.sd.s01.38.2007 　

    ISSN： 1816-8957 1816-3459

  84. Effects of Thermal Stresses on Rock Permeability with Application to the Thermal Extraction from Supercritical Rock Masses

    Chiba, R, Takashima Y, Takahashi, T, Ito, T, Hayashi, K, Hashida, T

    Proc. Renewable Energy 2006 – Advanced Technology Paths to Global Sustainability –　1575-1577　2006/10/09

  85. Estimation of Flow Pathway Structure in Enhanced Geothermal Systems by Analyzing Microseismic Events

    Ito, T, Osada, K, Baria, R

    Proc. Renewable Energy 2006 – Advanced Technology Paths to Global Sustainability –　1571-1574　2006/10/09

  86. Application of Point Stress Method to Hydro-fracturing Tectonic Stress Measurement

    Ito, T

    Proc. of the 16th European Conference of Fracture　1117-1118　2006/07/03

  87. Detection of Pressure and Flow Distribution in Reservoirs from Hydraulically-induced Microseismic Events and Application to the Soultz HDR Field

    Ito, T

    Workshop Proc. Stimulation of Reservoir and Induced Microseismicity　73-79　2006/06/29

  88. Laboratory Study of Trapping Enhancement by the In-situ Reaction Method for Geological Storage of CO2

    Ito, T, Kawamura, Y, Sekine, K, Hayashi, K

    Proc. 31st Workshop Geother. Reservoir Eng. (CD-ROM)　P02_04_01　2006/06/19

  89. A New Approach for Monitoring Pressure Propagation in Reservoirs based on Microseismic Events Caused by Hydraulic Stimulation

    Ito, T, Chiba, T, Osada, K, Hayahi, K

    Proc. 31st Workshop Geother. Reservoir Eng.　31　372-377　2006/01/30

  90. Innovative concept of hydrofracturing for deep stress measurement

    T. Ito, H. Kato, H. Tanaka

    In-Situ Rock Stress Measurement, Interpretation and Application　53-60　2006

  91. Crucial effect of system compliance on the maximum stress estimation in the hydrofracturing method: Theoretical considerations and field-test verification Peer-reviewed

    Takatoshi Ito, Akira Igarashi, Harumi Kato, Hisao Ito, Osam Sano

    EARTH PLANETS AND SPACE　58　(8)　963-971　2006

    DOI： 10.1186/BF03352601 　

    ISSN： 1343-8832

  92. Mapping of propagating pressure in reservoir from the data of microseismic events in the 1993 hydraulic stimulation at the Soultz HDR site Peer-reviewed

    Osada, K, Ito, T, Hayashi, K, Baria, R

    GRC Transactions　29　109-114　2005/09

  93. 微小地震情報に基づく水圧破砕時の貯留層における圧力伝播挙動の解析 Peer-reviewed

    長田和義, 伊藤高敏, 林 一夫, Roy Baria

    日本地熱学会誌　27　(3)　211-222　2005/07

    Publisher: THE GEOTHERMAL RESEARCH SOCIETY OF JAPAN

    DOI： 10.11367/grsj1979.27.211 　

    ISSN： 0388-6735

    More details Close

    In the hydraulic stimulation, massive fluid is injected into subsurface rock through drilled wells. Then a number of micro-seismic events are commonly observed. By analyzing the data of microseismic event associated with hydraulic stimulation, we can estimate the orientation, i.e. dip and strike, of the fracture which slides to induce micro-seismic event. From the estimated orientation taking into account the in-situ stresses and the Mohr-coulomb criterion to describe the critical condition of fracture sliding, we can estimate the pore pressure at the location of sliding fracture and at the time when the sliding occurs, in other words, when micro-seismic event occurs. The estimated values of pore pressure are sorted in a certain manner for each equally-divided spatial region, i.e. block, to give spatial distribution of pore pressure and its variation with time during hydraulic stimulation. For an example, we applied this method to the micro-seismic data observed during the hydraulic stimulation performed in September 1993 at Soultz field in France. We obtained successfully the estimated pore pressure distribution.

  94. Problem for the Maximum Stress Estimation by Hydrofracturing Method and Its Potential Solution Peer-reviewed

    Ito, T, Igarashi, A, Ito, H, Sano, O

    Proc. of the 40 th US Rock Mech. Symp. Alaska Rocks 2005　2005/06

  95. Thermoelastically-induced Fracture Permeability Enhancement Associated with Cold Fluid Injection and its Laboratory Verification Peer-reviewed

    Takatoshi Ito, Hisashi Watanabe, Kazuo Hayashi, Daniel Swenson

    Journal of the Geothermal Research Society of Japan　27　(2)　101-113　2005

    DOI： 10.11367/grsj1979.27.101 　

    ISSN： 1883-5775 0388-6735

  96. Effect of thermal deformation on fracture permeability in stressed rock masses Peer-reviewed

    Takatoshi Ito, Daniel Swenson, Kazuo Hayashi

    Elsevier Geo-Engineering Book Series　2　(C)　673-678　2004

    DOI： 10.1016/S1571-9960(04)80117-4 　

    ISSN： 1571-9960

  97. Utilization of mud weights in excess of the least principal stress to stabilize wellbores: Theory and practical examples Peer-reviewed

    T Ito, MD Zoback, P Peska

    SPE DRILLING & COMPLETION　16　(4)　221-229　2001/12

    ISSN： 1064-6671

  98. Laboratory and field verification of a new approach to stress measurements using a dilatometer tool Peer-reviewed

    T Ito, A Sato, K Hayashi

    INTERNATIONAL JOURNAL OF ROCK MECHANICS AND MINING SCIENCES　38　(8)　1173-1184　2001/12

    DOI： 10.1016/S1365-1609(01)00073-9 　

    ISSN： 1365-1609

  99. Role of Stress Controlling Flow Pathways in Geothermal Reservoirs

    T. Ito, K. Hayashi

    Proc. of the 3rd Euroconference on Rock Physics and Rock Mechanics-Thermo-Hydro-Mechanical Coupling in Fractured Rock　47　2000/11

  100. Fracture permeability and in situ stress to 7 km depth in the KTB Scientific Drillhole Peer-reviewed

    T Ito, MD Zoback

    GEOPHYSICAL RESEARCH LETTERS　27　(7)　1045-1048　2000/04

    DOI： 10.1029/1999GL011068 　

    ISSN： 0094-8276

  101. Laboratory verification of a new dilatmeter tool for stress measurement

    T Ito, K Hayashi, A Sato

    PACIFIC ROCKS 2000: ROCK AROUND THE RIM　881-884　2000

  102. Hydraulic fracture reopening pressure and the estimation of maximum horizontal stress Peer-reviewed

    T Ito, K Evans, K Kawai, K Hayashi

    INTERNATIONAL JOURNAL OF ROCK MECHANICS AND MINING SCIENCES　36　(6)　811-825　1999/09

    DOI： 10.1016/S0148-9062(99)00053-4 　

    ISSN： 0148-9062

  103. Stress and rock mechanics issues of relevance to HDR/HWR engineered geothermal systems: review of developments during the past 15 years Peer-reviewed

    KF Evans, FH Cornet, T Hashida, K Hayashi, T Ito, K Matsuki, T Wallroth

    GEOTHERMICS　28　(4-5)　455-474　1999/08

    DOI： 10.1016/S0375-6505(99)00023-1 　

    ISSN： 0375-6505

  104. Experimental study for stress measurements on electrical resistivity of rocks

    Y. Ito, S. Oyama, K. Hayashi

    Proceedings of the '99 Japan-Korea Joint Symposium on Rock Engineering　311　1999/08

  105. A Study on Stress Controlling Flow Pathways in HDR/HWR Geothermal Reservoirs Peer-reviewed

    ITO Takatoshi

    Geothermal Resources Council Transactions　223　259　1999

  106. Utilization of mud weights in excess of the least principal stress in extreme drilling environments

    T Ito, MD Zoback, P Peska

    ROCK MECHANICS FOR INDUSTRY, VOLS 1 AND 2　253-259　1999

  107. Stress concentration at the bottom of a borehole and its effect on borehole breakout formation Peer-reviewed

    T Ito, K Kurosawa, K Hayashi

    ROCK MECHANICS AND ROCK ENGINEERING　31　(3)　153-168　1998/07

    DOI： 10.1007/s006030050016 　

    ISSN： 0723-2632

  108. Utilization of Directional Drilling to Maximize Wellbore Pressures during Drilling

    T. Ito, M. Zoback

    Stanford Rock Physics & Borehole Geophysics Project　68　F9-1　1998/06

  109. Effects of Pressure Gradient around the Borehole on Pressure Decay at the Pressure Pulse Test

    伊藤 高敏

    Reports of Toyota Physical and Chemical Research Institute　50　25　1997/05

  110. Two methods for hydraulic fracturing stress measurements without the ambiguous reopening pressure Peer-reviewed

    T. Ito, A. Sato, K. Hayashi

    International journal of rock mechanics and mining sciences &amp; geomechanics abstracts　34　(3-4)　499　1997/04

    DOI： 10.1016/S1365-1609(97)00121-4 　

    ISSN： 0148-9062

  111. Conventional hydrofrac method in arbitrarily oriented stress fields

    A Sato, T Ito, K Hayashi

    ROCK STRESS　107-110　1997

  112. Residual stress in rock core samples and stress state at great depths

    T Ito, K Watanabe, K Hayashi

    ROCK STRESS　167-170　1997

  113. A study for in-situ stress measurements from circumferential deformation of borehole wall due to pressurization Peer-reviewed

    T Ito, K Hayashi

    ROCK MECHANICS TOOLS AND TECHNIQUES, VOLS 1 AND 2　891-896　1996

  114. In Situ Stress Measurements by Hydraulic Fracturing for a Rock Mass with Many Planes of Weakness Peer-reviewed

    ITO Takatoshi

    International Journal of Rock Mechanics and Mining Sciences & Geomechanics Abstracts　34　(1)　45　1996

    DOI： 10.1016/S0148-9062(96)00044-7 　

  115. Reliability of In Situ Stress Due to Similarity of Crack Orientation in Hydraulic Fracturing Stress Measurement Peer-reviewed

    ITO Takatoshi

    Transaction of the Japan Society of Mechanical Engineers　62　(603)　161-2566　1996

    Publisher: The Japan Society of Mechanical Engineers

    DOI： 10.1299/kikaia.62.2561 　

    ISSN： 0387-5008

    More details Close

    Hydraulic fracturing rock stress measurement utilizing shut-in pressures of transverse cracks, the reliability of evaluated in situ stress state depends upon the independence of crack orientation, qualitatively speaking, the reliability improves when orientation of cracks differs significantly from each other. In order to evaluate the relationship between independence and reliability, we introduced the condition number of a matrix which is completely determined by the orientation of transverse cracks induced by hydraulic fracturing. We examined 30 sets of artificial data, each set of which consisted of ten cracks generated by random sampling, under two given stress states, and investigated the relationship between the condition number and the reliability of the estimated stress state. It was revealed that the reliability and the condition number had strong correlation and, thus, the condition number is a very useful measure of the reliability of the estimated stress state.

  116. Shut-in pressure determination for hydraulic fracturing stress measurements under high temperature Peer-reviewed

    Takatoshi Ito, Tadasu Sasaki

    Journal of the Geothermal Research Society of Japan　17　(3)　233-242　1995

    DOI： 10.11367/grsj1979.17.233 　

    ISSN： 1883-5775 0388-6735

  117. Reliability of In Situ Stress evaluated by Hydraulic Fnacturing Stress Measurement Peer-reviewed

    ITO Takatoshi

    Transaction of the Japan Society of Mechanical Engineers　61　(592)　2599-2604　1995

    Publisher: The Japan Society of Mechanical Engineers

    DOI： 10.1299/kikaia.61.2599 　

    ISSN： 0387-5008

    More details Close

    Hydraulic fracturing stress measurement technique is the most well-known method for in situ stress measurements. However, a general method has not yet been established for estimating the reliability of the evaluated in situ stress. This paper presents a new method for estimating the reliability of the in situ stress evaluated by hydraulic fracturing stress measurement technique which utilizes a shut-in pressure and an orientation of cracks induced by hydraulic fracturing. The validity of the method was examined by applying it to two sets of artificial data constructed for eight cracks under a given stress state. The shut-in pressure for each crack was given by assuming the shut-in pressure to be equal to the normal stress acting perpendicularly to the crack. It was revealed that the shut-in pressure for each crack was most crucial for obtaining reliable results.

  118. MEASUREMENT OF IN-SITU HYDRAULIC PROPERTIES FROM THE PULSE TEST FOR THE CASE OF UNKNOWN INSITU PORE PRESSURE AND ITS APPLICATION TO HDR MODEL FIELDS Peer-reviewed

    T ITO, Y HIROSE, K HAYASHI

    GEOTHERMAL RESOURCES COUNCIL TRANSACTIONS, VOL 18　18　445-451　1994

    ISSN： 0193-5933

  119. IN-SITU STRESS MEASUREMENT BY HYDRAULIC FRACTURING AT THE KAMAISHI MINE Peer-reviewed

    K HAYASHI, T ITO

    INTERNATIONAL JOURNAL OF ROCK MECHANICS AND MINING SCIENCES & GEOMECHANICS ABSTRACTS　30　(7)　951-957　1993/12

    ISSN： 0148-9062

  120. ANALYSIS OF CRACK REOPENING BEHAVIOR FOR HYDROFRAC STRESS MEASUREMENT Peer-reviewed

    T ITO, K HAYASHI

    INTERNATIONAL JOURNAL OF ROCK MECHANICS AND MINING SCIENCES & GEOMECHANICS ABSTRACTS　30　(7)　1235-1240　1993/12

    DOI： 10.1016/0148-9062(93)90101-I 　

    ISSN： 0148-9062

  121. Reopening Behavior of Transverse Cracks in Hydraulic Fracturing Tectonic Stress Measurements Peer-reviewed

    ITO Takatoshi

    Transactions of the Japan Society of Mechanical Engineers　59　(561)　1287-1291　1993

    Publisher: The Japan Society of Mechanical Engineers

    DOI： 10.1299/kikaia.59.1287 　

    ISSN： 0387-5008

    More details Close

    The reopening behavior of a transverse crack which is induced on the surface of a borehole by hydraulic fracturing is analyzed to establish the methodology for hydraulic fracturing tectonic stress measurements, where, as a typical transverse crack, a penny-shaped crack which is induced perpendicularly to the borehole axis is considered. To this end, a model is constructed for analyzing the coupled problem of fluid flow in the crack and crack reopening behavior in an impermeable rock. The model takes into account the fact that the crack does not reclose perfectly upon deflation due to crack surface damage and minor shear displacement. The results show that the apparent reopening pressure, i.e., borehole pressure at which the pressure-time history clearly deviates from linearity, decreases and approaches the compressive tectonic stress normal to the crack plane with decreasing injection flow rate, and that it is almost proportional to the compressive tectonic stress independently of injection flow rate.

  122. ANALYSIS OF STRESS-INDUCED WELLBORE BREAKOUTS IN AN ARBITRARILY ORIENTED TECTONIC STRESS-FIELD Peer-reviewed

    T ITO, K HAYASHI, MD ZOBACK

    JSME INTERNATIONAL JOURNAL SERIES I-SOLID MECHANICS STRENGTH OF MATERIALS　35　(3)　265-270　1992/07

    ISSN： 0914-8809

  123. Regulation of water flow by actin-binding protein-induced actin gelatin Peer-reviewed

    T. Ito, A. Suzuki, T. P. Stossel

    Biophysical Journal　61　(5)　1301-1305　1992

    DOI： 10.1016/S0006-3495(92)81938-0 　

    ISSN： 0006-3495

  124. Relation between Reopening Pressure and Tectonic Stresses for Hydraulic Fracturing Tectonic Stress Measurements Peer-reviewed

    ITO Takatoshi

    Transactions of the Japan Society of Mechanical Engineers　58　(545)　1992

    DOI： 10.1299/kikaia.58.72 　

  125. Closure Process of Transverse Cracks after Shut-in in Hydraulic Fracturing Tectonic Stress Measurements Peer-reviewed

    ITO Takatoshi

    Transactions of the Japan Society of Mechanical Engineers　58　(547)　367-371　1992

    Publisher: The Japan Society of Mechanical Engineers

    DOI： 10.1299/kikaia.58.367 　

    ISSN： 0387-5008

    More details Close

    Closure process of a transverse crack crossing a wellbore is analyzed to discuss physical meanings of the pressure decay curve after shut-in during hydraulic fracturing tectonic stress measurements, where the crack is assumed to be perpendicular to the wellbore axis and one of the principal axes of the tectonic stress is assumed to be parallel to the wellbore axis. The analysis is based on the linear theory of elasticity and linear fracture mechanics. It is shown that the whole crack closes instantaneously when the downhole water pressure is equal to the compressive tectonic stress acting perpendicularly to the crack plane. The instantaneous crack closure appears as a point of maximum curvature on the pressure decay curve after shut-in. Therefore, the compressive tectonic stress normal to the crack plane is determined as the pressure at the point of maximum curvature. Although the point of maximum curvature appears less clearly on pressure decay curve when the fluid loss coefficient is large, the instantaneous crack closure can always be detected clearly by utilizing the relation of the inverse of the decrease rate of the downhill water pressure Vs the downhill pressure.

  126. CHARACTERISTICS OF SHUT-IN CURVES OF TRANSVERSE CRACKS IN HYDRAULIC FRACTURING STRESS MEASUREMENTS Peer-reviewed

    T ITO, K HAYASHI

    20TH ANNIVERSARY - GEOTHERMAL RESOURCES COUNCIL　16　651-656　1992

    ISSN： 0193-5933

  127. PHYSICAL BACKGROUND TO THE BREAKDOWN PRESSURE IN HYDRAULIC FRACTURING TECTONIC STRESS MEASUREMENTS Peer-reviewed

    T ITO, K HAYASHI

    INTERNATIONAL JOURNAL OF ROCK MECHANICS AND MINING SCIENCES & GEOMECHANICS ABSTRACTS　28　(4)　285-293　1991/07

    DOI： 10.1016/0148-9062(91)90595-D 　

    ISSN： 0148-9062

  128. Theoretical Analysis of Crack Reopening Behavior in Hydraulic Fracturing Tectonic Stress Measurements Peer-reviewed

    ITO Takatoshi

    Transactions of the Japan Society of Mechanical Engineers　57　(540)　1715-1719　1991

    Publisher: The Japan Society of Mechanical Engineers

    DOI： 10.1299/kikaia.57.1715 　

    ISSN： 0387-5008

    More details Close

    The reopening behavior of longitudinal cracks which are induced by hydraulic fracturing on the surface of a borehole is analyzed to establish the methodology of hydraulic fracturing tectonic stress measurements. To this end, a model is constructed to analyze the coupled problem of fluid flow in the crack and the crack reopening behavior in impermeable rock, based on the linear theory of elasticity and also on the linear fracture mechanics and taking into account that the crack does not reclose perfectly upon deflation due to crack surface damage and some minor shear displacement. The results show that the borehole pressure at the instant when the crack reopening occurs is just half of the pressure value predicted by the conventional theory. The borehole pressure at which the pressure-time history apparently deviates from a linear behavior is somewhat higher than the true pressure value at the crack reopening, and it increases with water injection rate.

  129. Determination of the Minimum Horizontal Principal Stress from Pressure Decay after Breakdown in Hydraulic Fracturing Peer-reviewed

    ITO Takatoshi

    Geothermal Resources Council Transactions　15　1991

  130. Closure Pressures for Hydraulic Fracturing Tectonic Stress Measurements Peer-reviewed

    ITO Takatoshi

    Transactions of the Japan Society of Mechanical Engineers　57　(542)　2345-2348　1991

    Publisher: The Japan Society of Mechanical Engineers

    DOI： 10.1299/kikaia.57.2345 　

    ISSN： 0387-5008

    More details Close

    A concept of crack closure pressure is proposed for evaluating tectonic stresses by the hydraulic fracturing stress measurement technique, based on the linear theory of elasticity and the linear fracture mechanics. The crack closure pressure is defined as a pressure value at a turning point appearing in the decrease rate of the downhole pressure vs the downhole pressure curve after the complete closure of the pressurizing circuit for hydraulic fracturing, i.e., shut-in. This is interpreted as a pressure at the instant when the crack which was induced by the hydraulic fracturing on the surface of a borehole closes completely after the shut-in. The relationship between the crack closure pressure and the tectonic stresses is very simple, and no material constants, such as the fracture toughness and hydraulic properties of the rock, appear in the relationship. Thus, it can be applied as a new and extremely useful formula for evaluating tectonic stresses by the hydraulic fracturing tectonic stress measurement technique.

  131. Effects of Fluid Penetration on Breakdown Pressures in Hydraulic Fracturing Tectonic Stress Measurements and Estimations of Breakdown Pressures Peer-reviewed

    ITO Takatoshi

    Transactions of the Japan Society of Mechanical Engineers　56　(526)　1432-1435　1990

    Publisher: The Japan Society of Mechanical Engineers

    DOI： 10.1299/kikaia.56.1432 　

    ISSN： 0387-5008

    More details Close

    A new method is proposed for the estimation of the so-called breakdown pressure in the hydraulic fracturing tectonic stress measurements. The stress field around the well bore was analyzed taking into account the influence of the fluid penetration into the porous rock due to the pressurization of the well bore. By the use of the stress field, the breakdown pressure, i. e., the well bore pressure required to induce cracks on the well bore was estimated based on a newly constructed fracture criterion. The criterion determines the breakdown pressure as a pressure value at which the maximum tensile effective stress at a characteristic depth beyond the well bore surface, reaches the tensile strength of the rock. To verify the new method, laboratory hydraulic fracturing experiments were conducted on cubical rock specimens under uniaxial compression. Results show that the breakdown pressures predicted by the classical method are erroneously lower than the experimental data when the uniaxial compressive stress is large. On the other hand, the breakdown pressures predicted by the present method perfectly agree with the experimental data independent of the magnitude of the uniaxial compressive stress.

  132. A Study for the Hydrofracture Breakdown Pressure Based on the Point Stress Criterion Peer-reviewed

    ITO Takatoshi

    Journal of the Mining and Materials Processing Institute of Japan　106　(3)　1990

    DOI： 10.2473/shigentosozai.106.115 　

  133. INSITU STRESS DETERMINATION BY HYDRAULIC FRACTURING - A METHOD EMPLOYING AN ARTIFICIAL NOTCH Peer-reviewed

    K HAYASHI, T ITO, H ABE

    INTERNATIONAL JOURNAL OF ROCK MECHANICS AND MINING SCIENCES & GEOMECHANICS ABSTRACTS　26　(3-4)　197-202　1989/07

    ISSN： 0148-9062

  134. A NEW METHOD FOR THE DETERMINATION OF INSITU HYDRAULIC-PROPERTIES BY PRESSURE PULSE TESTS AND APPLICATION TO THE HIGASHI HACHIMANTAI GEOTHERMAL-FIELD Peer-reviewed

    K HAYASHI, T ITO, H ABE

    JOURNAL OF GEOPHYSICAL RESEARCH-SOLID EARTH AND PLANETS　92　(B9)　9168-9174　1987/08

    ISSN： 0148-0227

  135. A New In-Situ Tectonic Stress Measurements and its Application to a Geothermal Model Field Peer-reviewed

    K. Hayashi, T. Shoji, H. Niitsuma, T. Ito, H. Abé

    Geothermal Resources Council Trans.　9　99-104　1985

  136. Growth Behavior of Hydraulically Created Crack and its Size Evaluation Using Well Logging Data - Crustal Rock Fracture Mechanics Approach - Peer-reviewed

    T. Shoji, K. Hayashi, T. Kojima, T. Ito, H. Takahashi, H. Abé

    Geothermal Resources Council Trans.　9　579-584　1985

Show all ︎Show first 5

Misc. 66

  1. Microseismic cloud growth process controlled by regional stress

    椋平祐輔, 伊藤高敏, 岡本京祐, 石橋琢也, 浅沼宏, 熊野裕介, 森谷祐一, YANG Meihua, YAN Kangnan, ZUO Yunhei, RUBINSTEIN Justin, HAERING Markus O.

    日本地熱学会学術講演会講演要旨集　2021　2021

  2. Environmental Impact of Telework with Direct Uses of Geothermal Heat: A Case Study of Naruko Area

    長谷川諒, 鈴木杏奈, 伊藤高敏, 稗貫峻一, 窪田ひろみ

    日本地熱学会学術講演会講演要旨集　2021　(3)　111-122　2021

    Publisher: THE GEOTHERMAL RESEARCH SOCIETY OF JAPAN

    DOI： 10.11367/grsj.44.111 　

    ISSN： 0388-6735

    eISSN： 1883-5775

    More details Close

    Geothermal potential area in Japan has been depopulated recently, and there have been distances between the geothermal potentials and most energy consumers living in urban areas. Since 2020, working from home (home-based telework) has spread rapidly due to the influence of the COVID-19. If some of the energy consumers work from the geothermal potential area, namely onsen areas, it would help to reduce the extra fossil fuel consumption, to reduce the environmental impact, and to save commuting costs and time. In this study, we quantitatively evaluated the advantages and feasibility of working from onsen in Naruko area, Osaki City, Miyagi Prefecture, as a case study. The environmental effects were analyzed by using the annual CO2 emissions and the costs, based on the perspective of the form of stay and the life-cycle assessments with four scenario conditions ((a) base system, (b) home-based telework in a city, (c) onsen-based telework (using hot spring only for bathing), and (d) onsen-based telework (using hot spring for bathing and heating)). Compared to the base system, the use of public baths in the onsen area can reduce CO2 emissions by about 1/3, and the use of bathing and heating by hot springs can reduce CO2 emissions by about 1/4. In the case of a short-term stay in the onsen area, the effects of reducing CO2 emission differed depending on the area where the worker is based and the season. The results indicates that some conditions of the short-term stay may results in higher CO2 emission than when nothing is done. Therefore, we expect that each of urban workers, companies, and onsen areas will change their awareness and take actions to be able to stay in the onsen area for a mid- to long-term.

  3. Constraint on the range of the focal mechanism of microseismicity with In-situ Stress Information

    椋平祐輔, 直井誠, 森谷祐一, 伊藤高敏, 浅沼宏, HAERING Markus O.

    石油技術協会誌(CD-ROM)　85　(1-6)　2020

    ISSN： 2436-2840

  4. Physical prosess of fault sliding driven by fluid pressure stimulation and its prevention

    伊藤高敏, 横山佳祐, 熊澤明信, 手塚和彦, 小川浩司, 横山幸也, 船戸明雄

    資源・素材(Web)　2020　2020

  5. Field tests of the Dual Bit Coring tool for Stress Measurement at Kamioka mine

    手塚和彦, 山本俊也, 伊藤高敏, 小川浩司, 横山幸也, 船戸明雄

    石油技術協会誌(CD-ROM)　85　(1-6)　2020

    ISSN： 0370-9868

  6. 水圧・減圧破砕による人工超臨界地熱貯留層造成に関する研究

    渡邉則昭, 坂口清敏, 平野伸夫, 鈴木杏奈, 後藤遼太, 三浦崇宏, BAILONG Liu, 伊藤高敏, 駒井武, 土屋範芳, 渡邉教弘, 石橋琢也, 浅沼宏

    日本地熱学会学術講演会講演要旨集　2019　35-35　2019/11

  7. Topological data analysis for estimating flow characteristics of 3D fracture network

    Suzuki Anna, Miyazawa Miyuki, Ito Takatoshi

    Proceedings of the 16th International Conference of Flow Dynamics　598-599　2019/11

  8. 地殻応力情報を用いた微小地震の断層面解範囲絞り込み

    椋平祐輔, 直井誠, FEHLER Michael C., 森谷祐一, 伊藤高敏, 浅沼宏, HAERING Markus O.

    日本地熱学会学術講演会講演要旨集　2019　2019

  9. 二重コアリングで得られたコアを用いる地殻応力測定法の研究

    熊澤明信, 伊藤高敏, 船戸明雄, 手塚和彦, 横山幸也

    資源・素材(Web)　2019　2019

  10. 二重解放コアを用いた地殻応力測定法の研究開発

    伊藤高敏, 手塚和彦, 横山幸也, 船戸明雄

    日本地熱学会学術講演会講演要旨集　2019　2019

  11. Crustal stress states around Nojima fault measured by using a new testing system for hydraulic fracturing

    Tatsuya Yokoyama, Aiming Lin, Weiren Lin, Takashi Danjo, Takatoshi Ito

    2018 AGU Fall Meeting,　2018/12

  12. A new flow model based on pore-scale network method for supercritical CO2 fracturing

    Liu Bailong, Suzuki Anna, Ito Takatoshi

    Proceedings of the 15th International Conference on Flow Dynamics　2018/11

  13. Link between tracer and microseismic analysis to comprehensive understanding of hydraulic feature of fractured geothermal reservoir

    Suzuki Anna, Mukuhira Yusuke, Ito Takatoshi, Horne Ronald N, Fehler M. C, Kang Peter

    Proceedings of the 18th International Symposium on Advanced Fluid Information　66-67　2018/11

  14. Analysis of rock fracture pattern and fluid flow by persistent homology

    Miyazawa Miyuki, Suzuki Anna, Okamoto Atsushi, Shimizu H, Obayashi Ippei, Ito Takatoshi

    Proceedings of the 15th International Conference on Flow Dynamics　2018/11

  15. 数値シミュレーションと組み合わせた構造解析による蛇紋岩の形成メカニズム推定

    宮澤美幸, 鈴木杏奈, 岡本敦, 清水浩之, 大林一平, 平岡裕章, 平岡裕章, 伊藤高敏

    日本地質学会学術大会講演要旨　125th　116　2018/09

    ISSN： 1348-3935

  16. き裂システムに対する注水時の間隙水圧伝播

    椋平祐輔, 森谷祐一, 伊藤高敏, 浅沼宏, HAERING M. O.

    日本地熱学会学術講演会講演要旨集　2018　2018

  17. 主応力比の大きい岩盤応力状態下における水圧破砕試験でのき裂挙動

    横山幸也, 坂口清敏, 伊藤高敏

    資源・素材(Web)　2018　2018

  18. Estimation of crack width in porous media by nano/micro particles Peer-reviewed

    Junzhe Cui, Anna Suzuki, Satoshi Uehara, Keiichi Shirasu, Takatoshi Ito

    Proceedings of the 15th International Conference of Flow Dynamics　2018

  19. Hybrid focal mechanism determination: Constraining focal mechanisms of injection induced seismicity using in situ stress data

    Y. Mukuhira, Y. Mukuhira, K. Fuse, M. Naoi, M. C. Fehler, H. Moriya, T. Ito, H. Asanuma, M. O. Häring

    Geophysical Journal International　215　1427-1441　2018/01/01

    DOI： 10.1093/GJI/GGY333 　

    ISSN： 0956-540X

  20. 南アフリカ金鉱山M2-5.5地震発生場掘削ICDPワークショップ報告

    小笠原宏, 矢部康男, 伊藤高敏, ワークショップ参加者

    J-DESCニュースレター　(9)　14　2016/04

  21. 主応力比の大きい岩盤応力下における水圧破砕試験でのき裂の再開口と閉口挙動に関する考察

    横山幸也, 坂口清敏, 伊藤高敏, LIN Weiren

    地盤工学研究発表会発表講演集(CD-ROM)　51st　2016

  22. 非在来型資源

    伊藤高敏

    岩の力学連合会50周年記念式典 記念誌「岩の力学 50年の歩みと未来への展望」　149-152　2014/06

    Publisher: 岩の力学連合会

  23. Fracturing Technology and its Experimental Research for Methane Hydrate Development

    ITO Takatoshi, TEZUKA Kazuhiko

    75　(12)　783-785　2011/12/05

    Publisher: 化学工学会

    ISSN： 0375-9253

  24. Development of borehole tangential deformation gage and its application for determining the stress in rock

    A. Igarashi, T. Ito, K. Sekine, K. Hayashi

    Proceeding of the 42nd US Rock Mech.Symp.　2008

  25. 地熱型再生可能エネルギー利用の実用化研究

    伊藤高敏, 新堀雄一

    伝熱　46　(196)　285-38　2007/07

  26. 195 Numerical simulation of CO_2 injection for CO_2 geological sequestration

    Sasaki Kenta, Fujii Takashi, Niibori Yuichi, Ito Takatoshi, Hashida Toshiyuki

    2007　(42)　187-188　2007/03/13

    Publisher: The Japan Society of Mechanical Engineers

  27. ボアホール変形メーターの試作と大滝根鉱山での検証試験

    五十嵐 哲, 伊藤 高敏, 林 一夫

    春季大会講演集. I, 資源編　18　(1)　109-110　2006/03/27

    ISSN： 1343-9898

  28. CO2地中固定のための人工バリアー形成の室内実験

    伊藤 高敏, 川村 典久, 関根 孝太郎, 林 一夫

    春季大会講演集. I, 資源編　18　(2)　1-2　2006/03/27

    ISSN： 1343-9898

  29. Progress in Advanced Geothermal Technology

    ITO Takatoshi

    Journal of the Japan Society of Mechanical Engineers　108　(1045)　928-929　2005/12/05

    Publisher: The Japan Society of Mechanical Engineers

    ISSN： 0021-4728

  30. 先進地熱エネルギー技術の新展開

    伊藤 高敏

    日本機械学会誌　108　(1045)　110-111　2005/12

  31. 臨界き裂に基づく地殻応力評価法に及ぼすき裂配向性の影響

    伊藤 高敏, 林 一夫

    春季大会講演集. I, 資源編　17　(1)　157-158　2005/03/28

    ISSN： 1343-9898

  32. き裂開口検出を目的とした坑壁変形センサの現位置試験

    五十嵐 哲, 加藤 春實, 伊藤 高敏, 林 一夫

    春季大会講演集. I, 資源編　17　(1)　159-160　2005/03/28

    ISSN： 1343-9898

  33. Review of the Hijiori HDR project : Concept of reservoir creation

    ITO T., ASANUMA H., OKABE T., KARASAWA H., TAKEHARA T., TEZUKA K.

    2004　A19　2004/11/20

  34. The hydromechanical behavior of a shear fracture in laboratory hydraulic fracture experiments

    SEKINE K., OKU H., NEMOTO K., ITO T., HAYASHI K.

    2004　A25　2004/11/20

  35. Estimation of flow-pathway structure based on micro-seismicity at Ogachi HDR field

    OSADA K., ITO T., KAIEDA H., HAYASHI K.

    2004　A34　2004/11/20

  36. Analysis of Injection Data at Kakkonda Geothermal Field Based on the Thermally-induced Stress-drop Model

    ITO T., KAJIWARA T., HAYASHI K.

    2003　63-63　2003/11/20

  37. Research of the Water Injection into the Rock Under High Temperature and High Pressure Water Conditions

    CHIBA R., TAKASHIMA Y., ITO T., HAYASHI K., HASHIDA T.

    2003　P03　2003/11/20

  38. Estimation of change in pore pressure distribution based on microseismicity at Soultz field

    OSADA K., ITO T., HAYASHI K., BARIA R.

    2003　87-87　2003/11/20

  39. ボアホール周方向変位計測のための新型センサーと地殻応力評価への応用

    伊藤 高敏, 小野 雅俊, 林 一夫

    春季大会講演集. I, 資源編　15　(1)　195-196　2003/03/27

    ISSN： 1343-9898

  40. Role of stress-controlled flow pathways in HDR geothermal reservoirs

    Takatoshi Ito, Kazuo Hayashi

    Pure and Applied Geophysics　160　(5-6)　1103-1124　2003

    Publisher: Birkhauser Verlag AG

    DOI： 10.1007/PL00012563 　

    ISSN： 0033-4553

  41. A Newly-Developed Transducer to Measure Circumferential Deformation of Borehole Wall in Sleeve Fracturing and its Application to Stress Estimation

    T. Ito, K. Hayashi

    Proceedings of 3rd. International Symposium of Rock Stress　289-294　2003

  42. Numerical Study on Optimum Injection Temperature Inferred from Coupled-Hydro-Thermal-Mechanical Behavior of Rock

    T. Ito, D. Swenson, K. Sekine, K. Hayashi

    Geothermal Resources Council Transaction　27　695-698　2003

  43. 坑井壁面の引張き裂 (Drilling Induced Tensile Wall Fracture) 発生挙動の室内実験による検討

    伊藤 高敏, 岩谷 悠平, 林 一夫

    春季大会講演集. I, 資源編　14　(1)　91-92　2002/03/28

    ISSN： 1343-9898

  44. 岩石の電気伝導性を利用した坑井壁面き裂の開口評価に関する研究

    伊藤 高敏, 斎藤 政人, 林 一夫

    東北大学流体科学研究所報告　13　39-52　2002

    Publisher: 東北大学流体科学研究所

    ISSN： 0916-2860

  45. A study on variation of facture permeability due to cooling

    ITO T., ISHII Y., HAYASHI K.

    2001　A07　2001/12/01

  46. A method to detect spatial distribution of flow pathway in geothermal reservoir based on microseismicity

    ITO T., OSADA K., HAYASHI K.

    2001　P18　2001/12/01

  47. 真のき裂開口圧による最大地殻応力評価法とその実用化システム

    伊藤 高敏, 加藤 春實, 狩野 嘉昭, 林 一夫

    資源・素材　2001　17-18　2001/09/24

    ISSN： 0919-7915

  48. 透水性き裂と地殻応力の関係に基づく地殻応力評価の可能性

    伊藤 高敏, 斉藤 美歌, 林 一夫

    一般発表(研究・業績発表)講演要旨集　2001　(1)　203-204　2001/03/01

    ISSN： 0919-293X

  49. Modeling of residual stress and micro-crack in rock caused by stress relief due to coring

    T Ito, K Hayashi

    ROCK MECHANICS: A CHALLENGE FOR SOCIETY　493-498　2001

  50. 水圧破砕法の標準法

    伊藤 高敏, 林 一夫

    資源・素材　2000　(1)　81-84　2000/10/03

    ISSN： 0919-7915

  51. Effect of stress on HDR/HWR reservoir formation at Ogachi and Soultz fields

    ITO T., MORIYA Y., HAYASHI K.

    1999　1999/12/01

  52. HDR/HWR型地熱貯留層の形成機構に関する最近の知見

    伊藤 高敏, 林 一夫

    資源・素材　1999　(1)　117-120　1999/11/01

    ISSN： 0919-7915

  53. 地殻応力と岩石コア中の残留応力の関係についての二次元有限要素モデルによる理論解析

    伊藤 高敏, 渡辺 耕一郎, 林 一夫

    一般発表(研究・業績発表)講演要旨集　1997　(1)　254-254　1999/03/25

    ISSN： 0919-293X

  54. 室内実験によるボアホール変形直接計測法の検討と地殻応力評価への応用

    佐藤 晃, 伊藤 高敏, 林 一夫

    一般発表(研究・業績発表)講演要旨集　1997　(1)　91-91　1999/03/25

    ISSN： 0919-293X

  55. 岩石電気抵抗の応力による変化特性と地殻応力評価

    伊藤 高敏, 小山 直, 林 一夫

    一般発表(研究・業績発表)講演要旨集　1999　(1)　134-135　1999/03

    ISSN： 0919-293X

  56. 掘削プロセスを考慮したボアホールブレイクアウト形成過程の数値シミュレーション

    伊藤 高敏, 服部 明, 林 一夫

    一般発表(研究・業績発表)講演要旨集　1999　(1)　74-75　1999/03

    ISSN： 0919-293X

  57. 水圧破砕法による釜石フィールドの現位置応力計測

    伊藤 高敏, 佐藤 晃, 林 一夫

    資源・素材　1996　(2)　91-94　1996/10/21

    ISSN： 0919-7915

  58. パルステスト透水特性評価法におよぼす不均一な初期間隙水圧分布の影響の解析

    伊藤 高敏, 大原 常好, 林 一夫

    一般発表(研究・業績発表)講演要旨集　1996　(1)　173-173　1996/03/29

    ISSN： 0919-293X

  59. 三次元地殻応力場とボアホールブレイクアウトの関係

    伊藤 高敏, 林 一夫

    資源・素材　1995　9-12　1995/09/18

    ISSN： 0919-7915

  60. ボアホール変形挙動に基づく地殻力学情報評価のための基礎研究

    伊藤 高敏, 林 一夫

    資源・素材　1995　9-9　1995/09/18

    ISSN： 0919-7915

  61. ボアホールブレイクアウト発生に及ぼす坑底応力場の影響

    伊藤 高敏, 黒澤 宏一, 林 一夫

    一般発表(研究・業績発表)講演要旨集　1995　(1)　67-67　1995/03/28

    ISSN： 0919-293X

  62. Evaluation of In Situ Hydraulic Properties of Formation at Great Depth

    K. hayashi, T. Ito, H. Abe

    Geothermal Sciences and Technology　4　(3)　145-157　1995

  63. 大深度地下岩体の現位置通水特性の計測評価法に関する研究

    林 一夫, 伊藤 高敏

    地下水学会誌　36　(2)　147-154　1994

    Publisher: Japanese Association of Groundwater Hydrology

    DOI： 10.5917/jagh1987.36.147 　

    ISSN： 0913-4182

    More details Close

    In the course of field experiments demonstrating engineering feasibility of HDR (Hot Dry Rock) geothermal heat extraction conducted in USA, UK and Japan, low recovery rate of water, which circulates through the heat extraction system consisting of injection and production wellbores and reservoir cracks, has been revealed to be one of the most serious problems against realizing the concept of HDR geothermal heat extraction. Thus it is definitely desirable to be able to estimate the amount of waterloss from the reservoir cracks beforehand prior to hydraulic fracturing for creating the reservoir cracks. The recovery rate of water is directly relating to the in-situ hydraulic properties of the rock mass which is surrounding the reservoir cracks. In the present paper, we propose a new method for measuring insitu hydraulic properties of a rock mass at great depth, more than a thousand meters. The method is based on the analysis of flow of water from the pressurized interval of a straddle packer system, set in a wellbore, back to the sections of wellbore outside the straddle packer system due to permeation through the rock. The method utilizes the time variation of the volumetric flow rate of the back flow stated above for a given level of pressure in the pressurized interval. Since this method can be applied to a variety of levels of the pressure in the pressurized interval, it will be possible to estimate the dependency of hydraulic properties on the reservoir pressure by applying the method proposed in the present paper.

  64. INVERSE PROBLEM ON THE EVALUATION OF HYDRAULIC-PROPERTIES OF ROCKS DEEP IN THE EARTHS CRUST AND EFFECT OF TUBULAR COMPLIANCE

    K HAYASHI, K NISHIBE, T ITO, H ABE

    JSME INTERNATIONAL JOURNAL SERIES I-SOLID MECHANICS STRENGTH OF MATERIALS　34　(4)　459-463　1991/10

    ISSN： 0914-8809

  65. Development of an Automatic and Objective Method for Evaluating Hydraulic Properties of Formations in a Depth

    K. Hayashi, K. Niiyama, T. Ito, H. Abe

    Geothermal Resoureces council Transactions　15　477-482　1991

  66. Scale Effect in Breakdown Pressure of Hydraulic Stress Mesurements

    T. Ito, K. Hayashi

    Scale Effects in Rock Masses, ed. A. P. Da Cunha, Balkema　289-295　1990

Show all ︎Show first 5

Books and Other Publications 3

  1. Proceedings of the 6th International Symposium on In-situ Rock Stress

    Ito, T

    ISRM Specialized Conference 2013　2013/08

  2. Nano-Mega Scale Flow Dynamics in Energy System

    Maruyama, S, Kobayashi, H, Maruta, K, Mizusaki, J, Nitsuma, H, Ito, T, Yamamoto, K, Aoyagi, R, Suekane, T, Akaku, K, Hashida, T

    Tohoku University Press　2008/03

  3. JSME Mechanical Engineer's Handbook, Fundamentals, Materials and Mechanics

    Ito, T

    2005/04/25

Presentations 217

  1. Environmental impact of telework with direct uses of geothermal heat: A case study of Naruko area

    Suzuki, A, Hasegawa, R, Hienuki, S, Kubota, H, Ito, T

    47th Stanford Geothermal Workshop

  2. アフターコロナの働き方はこれだ！温泉地域テレワークによる環境負荷提言効果の検証

    鈴木杏奈, 長谷川諒, 稗貫峻一, 窪田ひろみ, 伊藤高敏

    第8回東北大学若手研究者アンサンブルワークショップ

  3. テレワークと温泉熱利用による環境負荷低減効果の評価：鳴子地域のケーススタディ

    長谷川諒, 鈴木杏奈, 伊藤高敏, 稗貫峻一, 窪田ひろみ

    日本地熱学会令和3年学術講演会

  4. 地殻応力にスケールされる微小地震クラウドの成長過程

    椋平祐輔, 伊藤高敏, 岡本京祐, 石橋琢也, 浅沼宏, 熊野裕介, 森谷祐一, Meihua Yang, Kangnan Yan, Yunhei Zuo, Justin Rubinstein, Markus O. Häring

    日本地熱学会令和3年学術講演会

  5. 注水によるせん断すべり挙動解明のための実験的研究

    青木晃司, 椋平祐輔, 伊藤高敏

    日本地熱学会令和3年学術講演会

  6. 大深度地熱井における地殻応力測定を目的とした大口径8-1/2”用二重ビットコアリングツールの開発,

    手塚和彦, 永嶋希望, 伊藤高敏, 小川浩司, 船戸明雄, 横山幸也

    日本地熱学会令和3年学術講演会

  7. 地熱井への適用を考慮した二重解放コア変形原理による地殻応力測定法の室内実験による検討

    伊藤高敏, 手塚和彦, 小川浩司, 船戸明雄, 横山幸也

    日本地熱学会令和3年学術講演会

  8. Topological data analysis for mass tracer transport in fracture networks

    Goto, K, Suzuki, A, Minto, J, Ito, T

    18th International Conference on Flow Dynamics

  9. Application of core-based inversion to reconstruct stress field in an underground geoscience laboratory

    Ma, X, Mukuhira, Y, Ito, T

    the 21st International Symposium on Advanced Fluid Information

  10. Understanding failure phenomena accelerated by machine learning for subsurface energy development

    Aoki, K, Mukuhira, Y, Naoi, M, Ito, T

    the 21st International Symposium on Advanced Fluid Information

  11. Numerical simulation of permeability development along closed fracture by methane hydrate dissociation

    Zhang, R, Ito, T, Komai, T, Sakamoto, Y, Tenma, N

    the 21st International Symposium on Advanced Fluid Information

  12. Detection of P-S travel time for Low SNR Event by particle motion analysis

    Jingyi, S, Mukuhira, Y, Nagata, T, Nonomura, T, Moriya, H, Ito, T

    the 14th SEGJ International Symposium

  13. Characteristic of Pore Pressure Migration Clarified by Multidisciplinary Microseismic Analysis

    Mukuhira, Y, Ito, T, Moriya, H, Asanuma, H, Häring, M. O

    World Geothermal Congress 2020+1　2021/07/06

  14. Development and application of high stiffness fracturing systems for stress measurements corresponding to new standard in Japan

    Yokoyama, T, Funato, A, Ito, T, Ogawa, K, Nayuki, T

    55th US Rock Mechanics/Geomechanics Symposium

  15. Effect of system compliance on pressure-time curve at reopening and new standard in Japan

    Ito, T, Yokoyama, T

    55th US Rock Mechanics/Geomechanics Symposium

  16. A new method developed for rock stress measurement at deep depth in high temperature environment

    Ito, T, Kumazawa, A, Funato, A, Tezuka, K, Yokoyama, T

    World Geothermal Congress 2020+1　2021/06/15

  17. メタンハイドレートの分解を利用したフラクチャー浸透性改良の数値シミュレーション

    張 溶昌, 伊藤高敏, 天満則夫

    2021 (令和3) 年度 資源・素材学会 東北支部 総会・春季大会　2021/06/09

  18. Experimental study on fluid injection-induced fault slip

    Aoki, K, Mukuhira, Y, Ito, T

    JpGU Meeting 2021

  19. プロパントによる未固結砂層フラクチャー内の流動性保持に関する研究

    張 溶昌, 伊藤高敏, 駒井 武, 坂本靖英, 天満則夫

    第15 回岩の力学国内シンポジウム

  20. 二重解放コア変形原理による地殻応力測定法のため特殊ビット開発と実証

    手塚和彦, 小川浩司, 横山幸也, 船戸明雄, 伊藤高敏

    第15 回岩の力学国内シンポジウム

  21. In-situ crustal stress in inland Japan with application of DCDA method to rock core samples of seismic observation wells

    Omura, K, A. Funato, T. Ito

    American Geophysical Union (AGU) Fall Meeting 2020

  22. 微粒子を用いた砂層内フラクチャー伸展の制御技術とＣＴによる可視化実験

    伊藤高敏

    砂層型メタンハイドレートフォーラム　2020/12/16

  23. 二重解放コアを用いた地殻応力測定法の研究開発 －小口径ツールの実証―

    手塚和彦, 伊藤高敏, 小川浩司, 横山幸也, 船戸明雄

    日本地熱学会令和2年学術講演会

  24. 主応力比情報を用いた微小地震の断層面解範囲絞り込み

    椋平祐輔, 伊藤高敏, 浅沼 宏, M.O. Häring

    日本地熱学会令和2年学術講演会

  25. A breakthrough in rock stress measurement applicable deep and high temperature environment Invited

    Ito, T, Kumazawa, A, Tezuka, K, Ogawa, K, Yokoyama, T, Funato, A

    International Conference on Coupled Processes in Fractured Geological Media: Observation, Modeling, and Application (CouFrac)

  26. ICDP DSeis計画:M5.5余震発生帯におけるコア変形法（DCDA）による空間応力変化の評価

    美間良大, 田所遼悟, 吉田 峻輔, 東 充也, 阪口健介, L. Bennie, M. Siyanda, 矢部康男, 船戸明雄, 伊藤高敏, D. Raymond, 小笠原 宏

    日本地震学会秋季大会

  27. 神岡鉱山における二重コアビットによる地殻応力測定法の検証

    手塚和彦, 山本俊也, 伊藤高敏, 小川浩司, 横山幸也, 船戸明雄

    石油技術協会令和2年度学術大会

  28. 注水に伴う断層の動的すべり発生メカニズムの検討

    伊藤高敏, 横山圭祐, 椋平祐輔

    石油技術協会令和2年度学術大会

  29. 地殻応力情報を用いた微小地震の断層面解限定

    椋平祐輔, 直井 誠, 森谷祐一, 伊藤高敏, 浅沼 宏, M.O. Häring

    石油技術協会令和2年度学術大会

  30. First application result of DCDA method to the rock core samples from underground geoscience laboratory

    Ma, X, Y. Mukuhira, T. Ito

    20th International Symposium on Advanced Fluid Information

  31. 岩石内の流れを推定するパーシステントホモロジー

    鈴木杏奈, 宮澤美幸, 大林一平, 平岡裕章, 伊藤高敏

    日本応用数理学会2020年度年会

  32. 流体圧刺激による断層すべり発生のメカニズムと対策 Invited

    伊藤高敏, 横山佳祐, 熊澤明信, 手塚和彦, 小川浩司, 横山幸也, 船戸明雄

    資源・素材関係学協会合同秋季大会

  33. Estimating flow characteristics of 3D fracture network based on persistent homology

    Suzuki, A, M. Miyazawa, T. Ito, P. Kan

    InterPore2020

  34. Stress heterogeneity in the source region of the 2014 Orkney earthquake (M5.5), South Africa, estimated by ICDP-DSeis

    Yabe, Y, M. Kanematsu, M. Higashi, R. Tadokoro, S. Yoshida, K. Sugimura, H. Ogasawara, T. Ito, A. Funato, M. Ziegler, B. Liebenbeng, B. Watson, S. Mngadi, M. Manzi, R. Durrheim

    JpGU-AGU Joint Meeting 2020

  35. Estimation of focal mechanisms of more number of induced seismicity to understand fracture system in the geothermal reservoir

    Yan, K, M. Mukuhira, T. Ito, Y. Zuo, H. Asanuma, M.O. Häring

    JpGU-AGU Joint Meeting 2020

  36. Investigation of the physical link between the injection induced seismicity and information from borehole logging

    Mukuhira, Y, M. Ziegler, T. Ito, H. Asanuma, M.O. Häring

    JpGU-AGU Joint Meeting 2020

  37. Characterization of permeability based on topological data of fracture network

    Suzuki, A, M. Miyazawa, James Minto, T. Tsuji, T. Ito

    JpGU-AGU Joint Meeting 2020

  38. Experimental verification of the Dual Bit Coring method developed for stress measurement applicable in deep and high temperature environment

    Ito, T, A. Kumazawa, K. Tezuka, T. Yokoyama, K. Ogawa, A. Funato

    54th US Rock Mechanics/Geomechanics Symposium

  39. 地下3km以深の太古代泥質変成堆積岩中のランプロファイアー上で発生したM5.5地震の余震発生帯掘削調査

    小笠原宏, 矢部康男, 伊藤高敏, 船戸明雄, 廣野哲朗, 山本裕二, ICDP DSeis team

    日本材料学会第69回学術講演会

  40. The seismogenic zones of an M2.0-5.5 earthquakes successfully recovered in deep South African gold mines: the outcomes and the follow-up plan

    Ogasawara, H, B. Liebenberg, Y. Yabe, Y. Yokoyama, T. Hirono, D. Nisson, T.C. Onstott, T. Kieft, E. Cason, T. Wiersberg, M. Manzi, S. Mngadi, R. Durrheim, Y. Yamamoto, T. Ito, A. Funato, M. Ziegler, J. Mori, C. Dinske, the DSeis team

    European Geosciences Union (EGU) General Assembly 2020

  41. Stress state in the upper margin of aftershock zone of the 2014 Orkney earthquake (M.5.5), South Africa, estimated from analyses of drill cores and borehole breakout of ICDP-DSeis drillings

    Yabe, Y, M. Kanematsu, M. Higashi, R. Tadokoro, S. Yoshida, K. Sugimura, H. Ogasawara, T. Ito, A. Funato, M. Ziegler, B. Liebenbeng, B. Watson, S. Mngadi, M. Manzi, R. Durrheim

    European Geosciences Union (EGU) General Assembly 2020

  42. オイルサンド開発を⽬的とした間隙圧上昇によるせん断膨張と浸透性変化の検討

    楊 徳殻, 伊藤高敏, 柏原巧治, 内田 優

    資源・素材関係学協会合同春季大会

  43. Singular Behavior and Its Control of Hydraulic Fracture in Sands Verified in Laboratory Experiments with Aid of CT Scanner

    Ito, T., Yoshida, H., Mukuhira, Y., Yamamoto, K., Tsuchiya, Y.

    AGU fall meeting 2019　2019/12/09

  44. Understanding of the physics of induced seismicity from natural fracture and in-situstress information from borehole logging

    Mukuhira, Y., Ziegler, M., Ito, T.

    AGU fall meeting 2019　2019/12/09

  45. Stress state in the upper margin of aftershock zone of the 2014 Orkney earthqauke (M5.5), South Africa, measured from boring cores of ICDP-DSeis project

    31. Yabe, Y., Kanematsu, M., Higashi, R., Tadokoro, R., Yoshida, S., Sugimura, K., Ogasawara, H., Ito, T., Funato, A., Liebenberg, B., Watson, B., Mngadi, M., Manzi, M. and Durrheim, R.

    AGU fall meeting 2019　2019/12/09

  46. Potential borehole observatory in the aftershock zone at about 3.5 km depth of a 2014 M5.5 sinistral earthquake that the ICDP DSeis project has probed

    Ogasawara, H., Onstotte, T.C., Kieft, T., Wiersberg, T., Zimmer, M., Yabe, Y., Durrheim, R., Manzi, M., Cason, E., Leibenberg, B., Ziegler, M., Hirono, T., Ito, T., Funato, A., Yamamoto, Y. and ICDP DSeis team

    AGU fall meeting 2019　2019/12/09

  47. Consistency evaluation of three advanced stress measurement techniques upon Dual Core-bit Coring, Compact Conical-ended Borehole Overcoring and High Stiffness Hydraulic Fracturing at Kamioka mine, Japan

    Yokoyama, T., Ito, T., Tezuka, K. and Funato, A.

    AGU fall meeting 2019　2019/12/09

  48. Practical application of the dual core-bit tool for drilling stress record cores to stress measurements at Kamioka mine, Japan

    Tezuka, K., Yamamoto, T., Ito, T., Yokoyama, T. and Funato, A.

    AGU fall meeting 2019　2019/12/09

  49. A new method of rock stress measurements on stress record core obtained by the dual bit coring and its laboratory verification

    Kumazawa, A., Ito, T., Funato, A., Tezuka, K. and Yokoyama, T.

    AGU fall meeting 2019　2019/12/09

  50. Introduction of natural fracture information to induced seismicity analysis

    Mukuhira, Y., Ziegler, M., Ito, T., Asanuma, H., Häring, M. O.

    YSRM2019 & REIF2019　2019/12/01

  51. メタンハイドレート開発に関わる未固結地層破壊挙動の解明～フラクチャー・クリーンアウト現象の再現と可視化～

    伊藤高敏

    砂層型メタンハイドレートフォーラム　2019/12/03

  52. 注水による断層すべりの発生機構に関するシミュレーション

    横山佳祐,椋平祐輔,伊藤高敏

    日本地熱学会令和元年学術講演会　2019/11/20

  53. 地殻応力情報を用いた微小地震の断層面解範囲絞り込み

    椋平祐輔,直井 誠,M. C. Fehler, 森谷祐一,伊藤高敏,浅沼 宏,M.O. Häring

    日本地熱学会令和元年学術講演会　2019/11/20

  54. Topological data analysis for estimating flow characteristics of 3D fracture network

    The 16th International Conference of Flow Dynamics　2019/11/06

  55. Application of core-based inversion to reconstruct stress field in an underground geoscience laboratory

    Ma, X., Mukuhira, Y., Ito, T.

    19th International Symposium on Advanced Fluid Information　2019/11/06

  56. メタンハイドレート開発に関わる未固結地層破壊挙動の解明～フラクチャー・クリーンアウト現象の再現と可視化～

    伊藤高敏

    JOGMEC-TRCウィーク　2019/10/28

  57. irst field test of the dual core-bit tool for drilling stress record cores at kamioka mine, Japan

    Tezuka, K., Yamamoto, T., Ito, T., Yokoyama, T. and Funato, A.

    25th Formation Evaluation Symposium of Japan　2019/09/25

  58. 二重コアリングで得られたコアを用いる地殻応力測定法の研究

    熊澤明信, 伊藤高敏,船戸明雄,手塚和彦,横山幸也

    資源素材学会秋季大会　2019/09/24

  59. In-situ stress constraints on the focal mechanisms of induced seismicity

    Mukuhira, Y., Ito, T., Fehler, M. C., Naoi, M., Moriya, H., Asanuma, H., Häring, M. O.

    14th international congress on rock mechanics and rock engineering　2019/09/13

  60. Development of stress record coring method for stress measurement

    Ito, T.

    Annual Meeting of ISRM Commission on Crustal Stress and Earthquake　2019/09/15

  61. Effect of capillary force on performance of shale rock fracturing

    Liu, B., Suzuki, A. and Ito, T.

    53rd US Rock Mechanics / Geomechanics Symposium　2019/06/23

  62. Experimental study of tip screenout fracturing by using CT scanner

    Ito, T., Yoshida, H., Yamamoto, K. and Tsuchiya, Y.

    53rd US Rock Mechanics/Geomechanics Symposium　2019/06/23

  63. The 2019 overview of Drilling into Seismogenic zones of M2.0-5.5 earthquakes in South African gold mines (DSeis)

    Ogasawara, H., Liebenberg, B., Ziegler, M., Yabe, Y., Durrheim, R.J., Mngadi, S., Tau, S., Kaneki, S., Yokoyama, Y., Hirono, T., Onstott, T.C., Wiesberg, T., Zimmer, M., Kujawa, C., Conze, R., Aswegen, G.V., Wechsler, N. and ICDP DSeis team

    9th Int. Conf. on Deep Mining　2019/06/24

  64. In-situ stress around earthquake source faults in and beneath South African deep gold mines

    Yabe, Y., Abe, S., Ito, T., Ishida, A., Sugimura, K., Kanematsu, M., Higashi, M., Tadokoro, R. and Ogasawara, H.

    9th Int. Conf. on Deep Mining　2019/06/24

  65. A Novel Method to Estimate Fracture Permeability: Combining microseismic observational data and reservoir engineering model

    Yang, M., Mukuhira, Y., and Ito, T.

    JpGU meeting 2019　2019/05/26

  66. Constraint of focal mechanisms of induced seismicity by using misfit angles based on known in-situ stress

    Mukuhira, Y., Naoi, M., Fehler, M., Moriya, H., Ito, T., Asanuma, H., and Häring, M.O.

    JpGU meeting 2019　2019/05/26

  67. Topological characterization of 3D printing fracture networks

    Suzuki, A., Miyazawa, M., Konno, M. and Ito, T.

    JpGU meeting 2019　2019/05/26

  68. Estimation of fracture apertures in fractured porous media by nano-/microparticles

    Suzuki, A., Cui, J., Zhang, Y., Li, K., Horne, R.N. and Ito, T.

    JpGU meeting 2019　2019/05/26

  69. Causality between induced seismicity b-value reduction and stress state of existing fractures

    Mukuhira, Y., Fehler, M., Ito, T., Asanuma, H., and Häring, M.O.

    JpGU meeting 2019　2019/05/26

  70. Comparison of stress field change around a fault by dynamic fault rupture simulation using 3D-FEM

    Iwata, N., Kiyota, R., Aydan, O., Ito, T. and Miura, F.

    Rock Dynamics Summit　2019/05/07

  71. Effects of fault geometry and subsurface structure model on the strong motion and surface rupture induced by the 2014 Kamishiro Fault Nagano Earthquake

    Iwata, N., Kiyota, R., Aydan, Ö., Ito, T. and Miura, F.

    Rock Dynamics Summit　2019/05/07

  72. Spatial variation in stress in seismogenic zones in South African gold mines

    Ogasawara, H., Ishida, A., Sugimura, K., Yabe, Y., Abe, S., Ito, T., Funato, A., Kato, H., Liebenberg, B., Hofmann, G., Scheepers, L., Durrheim, R.J. and The SATREPS & DSeis teams,

    Rock Dynamics Summit　2019/05/07

  73. Rock stresses around actual faults measured by using a hydraulic fracturing technique

    Yokoyama, T., Lin, W., Danjo, T. and Ito, T.

    Rock Dynamics Summit　2019/05/07

  74. Experimental study on hydraulic fracturing in unconsolidated sands for its application to methane hydrate development

    Ito, T. and Tenma, N.

    AAPG Geosciences Technology Workshop: Gas Hydrates – From Potential Geohazard to Carbon-Efficient Fuel?　2019/04/15

  75. An overview of the completed ICDP project, Drilling into Seismogenic zones of M2.0-5.5 earthquakes in South African gold mines (DSeis)

    Ogasawara, H., Liebenberg, B.,Yabe, Y., Durrheim, R., Ziegler, M., Manzi, M., Mngadi, S., Onstott, T., Funato, A., Ito, T., Hirono, T., Kaneki, S., Yokoyama, Y., Yamamoto, Y. and ICDP DSeis team

    EGU　2019/04/07

  76. In-situ stress around earthquake source faults in and beneath South African deep gold mines

    Yabe, Y., Abe, S., Ito, T., Ishida, A., Sugimura, K., Kanematsu, M., Higashi, M., Tadokoro, R., Ogasawara, H., Funato, A., Kato, H., Watson, B., Mngadi and Durrheim, R.

    EGU　2019/04/07

  77. 断層面の形状や地質構造の違いによる強震動と断層変位の比較：神城断層地震を事例として

    岩田 直樹, 清田 亮二, 藍檀 オメル, 伊藤 高敏, 三浦 房紀

    第46回岩盤力学に関するシンポジウム　2019/01/12

  78. 3次元有限要素法による動的破壊シミュレーションに基づく断層パラメータの 違いによる断層周辺の応力変化

    岩田 直樹, 清田 亮二, 藍檀 オメル, 伊藤 高敏, 三浦 房紀

    第４６回岩盤力学に関するシンポジウム　2019/01/12

  79. Topological data analysis and 3D printing technologies for understanding of flow in fracture networks

    Suzuki, A, Miyazawa, M, Ito, T

    American Geophysical Union Fall Meeting 2018　2018/12/10

  80. Constraint of focal mechanisms of induced seismicity by analyzing consistency of slip vector using in-situ stress

    Mukuhira, Y, Fuse, K, Naoi, M, Ito, T, Fehler, M.C, Moriya, H, Asanuma. H, Haring, M.O

    American Geophysical Union Fall Meeting 2018　2018/12/10

  81. き裂システムに対する注水時の間隙水圧伝播 International-presentation

    椋平祐輔, 森谷祐一, 伊藤高敏, 浅沼 宏, Haring Marcus

    日本地熱学会平成30年学術講演会　2018/11/13

  82. A Numerical Study on Permeability enhancement caused by pore-pressure driven shear dilation for oil sands development

    Watanabe, M, Ito, T, Tamagawa, T, Tezuka, K

    International Conference on Coupled Processes in Fractured Geological Media: Observation, Modeling, and Application　2018/11/12

  83. Numerical study to learn different fracturing performance induced by supercritical CO2 and aqueous fluids

    Liu, B, Suzuki, A, Ito, T

    International Conference on Coupled Processes in Fractured Geological Media: Observation, Modeling, and Application　2018/11/12

  84. Estimation of crack width in porous media by nano/micro particles

    Cui, J, Suzuki, A, Ito, T

    International Conference on Coupled Processes in Fractured Geological Media: Observation, Modeling, and Application　2018/11/12

  85. Introduction of in-situ stress information from borehole logging to source characterization of microseismic events

    Mukuhira, Y, Fuse, K, Naoi, M, Ito, T, Fehler, M.C, Moriya, H, Asanuma. H, Haring, M.O

    The 13th SEGJ International Symposium　2018/11/12

  86. A new flow model based on Pore Scale Netwrok Method for supercritical CO2 fracturing

    Liu, B, Suzuki, A, Ito, T

    The 15th International Conference on Flow Dynamics　2018/11/07

  87. Analysis of rock fracture pattern and fluid flow by persistent homology

    The 15th International Conference on Flow Dynamics　2018/11/07

  88. Estimation of crack width in porous media by nano/micro particles

    Cui, J, Suzuki, A, Uehara, S, Shirasu, K, Ito, T

    The 15th International Conference on Flow Dynamics　2018/11/07

  89. Dependency of the injection induced seismicity b-value on the stress state of existing fractures

    Mukuhira, Y, Fehler, M, Ito, T, Asanuma, H, Haring, M.O

    Banff 2018 International Induced Seismicity Workshop　2018/10/24

  90. 誘発地震b値のせん断応力依存性 International-presentation

    椋平祐輔, 伊藤高敏, Fehler, M.C, 浅沼 宏, Haring, M.O

    日本地震学会2018年度秋季大会　2018/10/09

  91. 南アフリカ大深度金鉱山で発生したMw2.2の地震の震源域の応力場 International-presentation

    矢部康男, 阿部周平, 小笠原宏, 伊藤高敏, 船戸明雄, Drurheim, R, Yilmaz, H, Hofmann, G

    日本地震学会2018年度秋季大会　2018/10/09

  92. ICDP 南アフリカ金鉱山 地震発生場掘削の完了 International-presentation

    小笠原宏, 矢部康男, 伊藤高敏, DSeisチーム(ICDP

    日本地震学会2018年度秋季大会　2018/10/09

  93. 主応力比の大きい地盤応力状態下における水圧破砕試験でのき裂挙動 International-presentation

    横山幸也, 坂口清敏, 伊藤高敏

    資源素材学会秋季大会　2018/09/10

  94. 数値シミュレーションによるフラクチャー分岐特性の考察 International-presentation

    伊藤高敏

    資源素材学会秋季大会　2018/09/10

  95. 数値シミュレーションと組み合わせた構造解析による蛇紋岩の形成メカニズム推定 International-presentation

    宮澤美幸, 鈴木杏奈, 岡本敦, 清水浩之, 大林一平, 平岡裕章, 伊藤高敏

    日本地質学会第125年学術大会　2018/09/05

  96. 大深度南アフリカ金鉱山の地震発生場での岩盤応力測定 International-presentation

    小笠原宏, 石田亮壮, 小笠原宏幸, 杉村幸佑, 野田 拓, 阿部周二, 矢部康男, 加藤春實, 伊藤高敏, 船戸明雄

    第53回地盤工学研究発表会　2018/07/24

  97. エネルギー資源開発のための注水による断層すべりに及ぼす岩盤応力の影響 International-presentation

    伊藤高敏, 横山圭祐

    第53回地盤工学研究発表会　2018/07/24

  98. Current Status of Research and Development on Supercritical Geothermal Resources in Japan

    Asanuma, H, Mogi, T, Tsuchiya, N, Watanabe, N, Naganawa, S, Ogawa, Y, Fujimitsu, Y, Kajiwara, T, Osato, K, Shimada, K, Horimoto, S, Sato, T, Ito, T, Yamada, S, Kondo, S, Watanabe, K, Gotoh, Y, Okada, H, Yoshida, Y, Nagasawa, Y, Koyama, A

    Grand Renewable Energy 2018 International Conference and Exhibition　2018/07/17

  99. 間隙圧上昇によるシェアダイレーションと浸透性変化挙動の数値シミュレーション International-presentation

    渡辺雅大, 伊藤高敏, 玉川哲也, 手塚和彦

    平成30年度石油技術協会春季講演会　2018/06/13

  100. CT スキャナを用いた室内実験によるスクリーンアウト現象の検討 International-presentation

    吉田日向, 伊藤高敏, 山本晃司, 土屋慶洋

    平成30年度石油技術協会春季講演会　2018/06/13

  101. タンハイドレート開発を目的とした未固結砂層のフラクチャリングに関する基礎研究 International-presentation Invited

    伊藤高敏, 天満則夫

    平成30年度石油技術協会春季講演会　2018/06/13

  102. 既存岩石コアへコア変形法を適用した原位置地殻応力測定 International-presentation

    小村健太郎, 林 為人, 伊藤高敏, 船戸明雄

    日本地球惑星科学連合2018大会　2018/05/20

  103. 個別要素法シミュレーションによるせん断帯き裂構造に及ぼす応力状態の影響の解析 International-presentation

    布施知正, 岡本 敦, 伊藤高敏, 清水浩之

    日本地球惑星科学連合2018大会　2018/05/20

  104. Analysis of rock fracture patterns by Persistent Himology

    Suzuki, A, Miyazawa, M, Okamoto, A, Shimizu, H, Hirooka, Y, Obayashi, I, Ito, T

    Japan Geoscience Union Meeting　2018/05/20

  105. The status of on-going drilling into seismogenic zones of M2.0 - M5.5 earthquakes from deep South African gold mines (DSeis)

    Ogasawa, H, Durrheim, R, Manzi, M, Yabe, Y, Onstott, T, Ziegler, M, Ito, T, Liebenberg, B, Grobbelaar, M, Ellsworth, W, Boettcher, M, Wechsler, W, Aswegen, G, Somala, S.N, the ICDP DSeis team

    European Geosciences Union General Assembly 2018　2018/04/08

  106. Core and borehole logging and stress measurements of a 817 m long borehole drilled from 2.9 km depth toward the Moab Khotsong 2014 M5.5 aftershock zone (ICDP DSeis project in South Africa)

    Ziegler, M, Rickenbacher, M, Berset, N, Liebenberg, B, Ishida, A, Sugimura, K, Noda, T, Ogasawara, H, Mngadi, S, Durrheim, R, Ito, T, Funato, A, the ICDP DSeis team

    European Geosciences Union General Assembly 2018　2018/04/08

  107. コア変形法（DCDA）における改良ビットの効果について International-presentation

    船戸明雄, 伊藤高敏

    野島プロジェクト研究成果報告会　2018/03/25

  108. 南アフリカ金鉱山の地震発生場における応力・強度・ひずみ変化の現位置計測 International-presentation

    小笠原宏, 石田亮壮, 阿部周平, 矢部康男, 伊藤高敏, 船戸明雄, 小笠原宏幸, 安富達就, 杉村幸佑, 野田 拓, DSeis研究チーム

    「災害の軽減に貢献するための地震火山観測研究計画」成果報告　2018/03/14

  109. Constraining of focal mechanisms of induced seismicity using borehole logging information

    Mukuhira, Y, Fuse, K, Naoi, K, Fehler, M, Ito, T, Moriya, H, Asanuma, H, Haring, M.O

    The 43rd Stanford Geothermal Workshop　2018/02/12

  110. 3次元有限要素法による2014年神城断層地震の地震動再現解析 International-presentation

    岩田 直樹, 清田 亮二, 足立 光, 藍檀 オメル, 伊藤 高敏, 三浦 房紀

    第45回岩盤力学に関するシンポジウム　2018/01/15

  111. X線CTスキャナを利用した水圧破砕き裂伸展挙動の研究

    長野優羽

    第14回岩の力学国内シンポジウム　2017/01/10

  112. Determination of Focal Mechanism of Induced Seismicity by using Regional Stress Data International-presentation

    AGU Fall Meeting　2016/12

  113. Estimate of the Stress State in an Earthquake Source Region in a South African Deep Gold Mine by Diametrical Core Deformation Analysis (DCDA) International-presentation

    AGU Fall Meeting　2016/12

  114. Investigation into the Physical Process of Sand Production in Unconsolidated Sands by Laboratory Experiments using X-ray CT for Methane Hydrate Development International-presentation

    AGU Fall Meeting　2016/12

  115. Propagation Speed of Pore Pressure throughout Permeable Fracture during Hydraulic Stimulation International-presentation

    AGU Fall Meeting　2016/12

  116. 個別要素法による未固結地層フラクチャリング挙動に影響を与える要因の検討

    第8回メタンハイドレート総合シンポジウム (CSMH-8)　2016/12

  117. Effect of Shear Dilation on Fault Slip Induced by Fluid Injection International-presentation

    The 13th International Conference on Flow Dynamics (ICFD2016)　2016/10

  118. Investigation of Distinct Element Modeling to Represent Hydraulic Fracturing Behavior in Unconsolidated Sand International-presentation

    The 13th International Conference on Flow Dynamics (ICFD2016)　2016/10

  119. 主応力比の大きい岩盤応力下における水圧破砕試験でのき裂の再開口と閉口挙動に関する考察

    第51回地盤工学研究発表会　2016/09

  120. 水圧破砕法による初期地圧測定方法の基準化について

    第51回地盤工学研究発表会　2016/09

  121. 地震発生に伴う震源断層近傍の応力変化

    第51回地盤工学研究発表会　2016/09

  122. 地熱貯留層の力学と応力

    地熱協会技術部講演会　2016/07/11

  123. Stress State Analysis of Fault Plane of Large Induced Seismicity International-presentation

    The 50th US Rock Mechanics / Geomechanics Symposium　2016/06

  124. A proposed Method and Its Application of Deep Stress Measurements International-presentation

    Japan Geoscience Union Meeting 2016　2016/05/22

  125. Development of the Deep Rock Stress Tester, DRST International-presentation

    The 7th International Symposium on In-situ Rock Stress　2016/05

  126. Estimate of the Stress State of Earthquake Source Region in a South African Deep Gold Mining by Diametrical Core Deformation Analysis (DCDA) International-presentation

    Japan Geoscience Union Meeting 2016　2016/05

  127. Laboratory Study of Sand Production in Unconsolidated Sands by Using X-ray CT for Methane Hydrate Development International-presentation

    SPE Workshop“Sand Management Workshop”　2016/04/25

  128. Causality between Expansion of Seismic Cloud and Maximum Magnitude of Induced Seismicity in Geothermal Feld International-presentation

    EGU General Assembly 2016　2016/04

  129. Drilling into Seismogenic Zones of M2.0-M5.5 Earthquakes in Deep South African Gold Mines (DSeis) International-presentation

    EGU General Assembly 2016　2016/04

  130. 圧力変化を利用したＣＯ2地中貯留層からの漏洩防止法の検討

    資源・素材学会 平成28(2016)年度 春季大会　2016/03/28

  131. 南アフリカ金鉱山の地震発生場における応力・強度・ひずみ変化の現位置計測

    平成27年度「災害軽減に貢献するための地震火山観測研究」成果報告シンポジウム　2016/03

  132. 個別要素法による特異な未固結地層フラクチャリング挙動再現の試み

    第7回メタンハイドレート総合シンポジウムCSMH-7　2015/12/02

  133. 未固結層からの出砂過程の室内実験による可視化観察

    第7回メタンハイドレート総合シンポジウムCSMH-7　2015/12/02

  134. 未固結地層の力学特性および拘束圧がフラクチャリング挙動に与える影響に対する個別要素法解析

    資源・素材学会東北支部平成27年度秋季大会研究発表講演会　2015/11/16

  135. Hydro fracturing method and stress estimation by analyzing core shape International-presentation

    The ICDP DSeis Workshop“Drilling into Seismogenic Zones of M2.0-5.5 earthquakes in South African gold mines　2015/11/01

  136. How the information of rock stress is useful for subsurface development and how it is measured at deep depths International-presentation

    The 21st Formation Evaluation Symposium of Japan　2015/10/13

  137. 「Slip-able area」の概念に基づく水圧刺激時の誘発地震リスクアセスメント法の提案

    日本地熱学会平成27年学術講演会　2015/10

  138. DEM Simulation for the Evaluation of Fracture Toughness during Hydraulic Fracturing International-presentation

    The Twelfth International Conference on Flow Dynamics ICFD2015　2015/10

  139. Numerical Modeling of Fault Shear Slip Induced by Fluid Injection International-presentation

    The Twelfth International Conference on Flow Dynamics ICFD2015　2015/10

  140. 南アフリカ大深度金鉱山での地震被害低減のための震源至近距離観測研究 – SATREPS等６カ年の活動のまとめ –

    日本地震学会2015年度秋季大会　2015/10

  141. 注水による断層すべりの数値シミュレーション

    平成27年度資源・素材関係学協会合同秋季大会　2015/09/10

  142. 個別要素法によるフラクチャリングシミュレーションにおける破壊じん性値評価手法の開発

    平成27年度資源・素材関係学協会合同秋季大会　2015/09/08

  143. メタンハイドレート開発を目的とした未固結地層におけるフラクチャー挙動の実験的研究

    第50回地盤工学研究発表会　2015/09/02

  144. Development of Experimental Apparatus for Real-time Observation of Hydraulic Fracture in Unconsolidated Sands by X-ray CT Method International-presentation

    School of Civil and Environmental Engineering, Georgia Institute of Technology　2015/08/04

  145. X線CT を利用した未固結砂層の破壊と出砂の室内実験

    平成27 年度石油技術協会春季講演　2015/06/11

  146. 石油傾斜井のkm 級深度における原位置の地殻応力評価へのコア変形法の適用

    平成27 年度石油技術協会春季講演　2015/06/11

  147. Development of Experimental Apparatus for Real-time Observation of Hydraulic Fracture in Unconsolidated Sands by X-ray CT method International-presentation

    49th US Rock Mechanics Geomechanics Symposium　2015/06

  148. 不均質構造で生じる岩石内部残留応力モデル

    日本材料学会第６４期学術講演会　2015/05/23

  149. 粒状体個別要素法による既存き裂を考慮した岩盤フラクチャリングのシミュレーション

    日本材料学会第６４期学術講演会　2015/05/23

  150. 供試体力学物性が未固結堆積層水圧破砕に及ぼす影響に関する個別要素法解析

    第6回メタンハイドレート総合シンポジウム　2014/12/03

  151. 模擬未固結地層内フラクチャー伸展挙動の可視化手法の開発

    第6回メタンハイドレート総合シンポジウム　2014/12/03

  152. Estimation of the Cumulative Fault Area Under Critical State Based on Microseismic Dataset at Hydraulic Stimulation for Seismic Risk Assessment International-presentation

    2014 AGU Fall Meeting　2014/12

  153. A New Concept for Measuring Rock Stress at Depth Using a Core Obtained by Drilling International-presentation

    The eleventh International Conference on Flow Dynamics (ICFD2014)　2014/10

  154. Comprehensive Evaluation of the Initial Rock Stress Carried Out as Part of a 2000m All Core Borehole Investigation International-presentation

    2014 ISRM International Symposium - the 8th Asian Rock Mechanics Symposium (ARMS8)　2014/10

  155. Hydro-thermal-mechanical Coupled Simulation of Fluid Flow in Fracture at Depths for Geothermal Development International-presentation

    The eleventh International Conference on Flow Dynamics (ICFD2014)　2014/10

  156. Real-time Observation of Hydraulic Fracture Growth in Soft Rocks under Confining Stress Using X-ray CT International-presentation

    2014 ISRM International Symposium - the 8th Asian Rock Mechanics Symposium (ARMS8)　2014/10

  157. 封圧を受ける岩体の熱収縮による単一き裂の開口挙動

    日本地熱学会平成26年学術講演会　2014/10

  158. Flow-coupled DEM modeling for hydraulic fracturing in unconsolidated sands International-presentation

    14th International Conference of the International Association for Computer Methods and Advances in Geomechanics (14th ICIACMAG)　2014/09

  159. WG13（水圧破砕法）基準化委員会の方向性

    第49回地盤工学研究発表会　2014/07/15

  160. 熊野海盆における大水深海底地層での水圧破砕地殻応力評価

    第49回地盤工学研究発表会　2014/07/15

  161. 弾性異方性を考慮したコア変形モデル

    資源・素材学会東北支部平成26年度春季大会　2014/06/17

  162. Laboratory Study for Pore Water Effect on Hydraulicallyinduced Fracture Behavior in Unconsolidated Sands International-presentation

    48th US Rock Mechanics Geomechanics Symposium　2014/06/04

  163. Flow-coupled DEM simulation for hydraulic fracturing in pre-fractured rock International-presentation

    48th US Rock Mechanics Geomechanics Symposium　2014/06/02

  164. 水圧刺激時の微小地震データに基づく破壊可能な断層面積 ”Slip-able area” 評価の試み

    日本地球惑星科学連合2014年大会　2014/05/02

  165. 低温水流入に伴うき裂開口幅変化の数値解析

    日本地球惑星科学連合2014年大会　2014/05/02

  166. メタンハイドレートと地熱と日本

    平成２５年度触媒学会東北地区講演会「化石燃料を上手に使う！ ～ポスト原発のエネルギー資源～」　2013/09/17

  167. Development of Unconsolidated Sand Model Using Distinct Element Method for Hydraulic Fracturing International-presentation

    6th Int. Symposium on In-situ Rock Stress　2013/08/20

  168. Diametrical Core Deformation Analysis (DCDA) – Measuring Device and Laboratory Verification - International-presentation

    6th Int. Symposium on In-situ Rock Stress　2013/08/20

  169. Distinct Element Analysis of the Effect of Brittleness Index in Hydraulic Fracturing International-presentation

    6th Int. Symposium on In-situ Rock Stress　2013/08/20

  170. Experiments to Investigate Effects of the Intermediate Principal Stress on the Borehole Breakout Development International-presentation

    6th Int. Symposium on In-situ Rock Stress　2013/08/20

  171. Hydraulic Fracturing Behavior in Soft Rocks under Confining Stresses Observed by X-ray CT Method International-presentation

    6th Int. Symposium on In-situ Rock Stress　2013/08/20

  172. Systematic Approach for Initial Rock Stress Estimation Using Borehole and Core Sample in a Deep Geological Location International-presentation

    6th Int. Symposium on In-situ Rock Stress　2013/08/20

  173. Difficulties and Possible Solutions for Deep Stress Measurements International-presentation

    6th Int. Symposium on In-situ Rock Stress　2013/08/20

  174. Distinct Element Analysis for Hydraulic Fracturing in Shale –Effect of Brittleness on the Fracture Propagation - International-presentation

    47th US Rock Mechanics / Geomechanics Symp.　2013/06/23

  175. Experimental Study of Hydraulic Fracturing in Unconsolidated Sands Using X-ray CT Method International-presentation

    47th US Rock Mechanics / Geomechanics Symp.　2013/06/23

  176. Development of Unconsolidated Sand Model Using Distinct Element Method and Calibration of Micro Parameters for Hydraulic Fracturing

    メタンハイドレート総合シンポジウムCSMH-4　2012/12

  177. 延性帯EGSの岩石力学

    日本地熱学会平成24年度学術講演会　2012/10

  178. Numerical Simulation of Cavity Expansion in Unconsolidated Sand Using Distinct Element Method

    2012年資源素材学会秋季大会　2012/09

  179. CO2 貯留層からの漏洩修復法を検証するためのX線CT法による室内実験

    2012年資源素材学会秋季大会　2012/09

  180. 破砕流体の浸透を伴う未固結地層フラクチャリング挙動のX線CT法による検討

    石油技術協会2012年春季大会　2012/06

  181. 微小地震に基づく流体移動の評価法と地熱開発への応用

    日本地球惑星科学連合大会2012　2012/05/20

  182. Stress State at the Expedition 319 Drilling Site Estimated from Hydrofracturing Data and Core Deformation Taking account of the System Compliance Effect International-presentation

    International Conference on a New Perspective of Great Earthquake along Subduction Zone　2012/02/28

  183. Laboratory Verification of the Core Deformation Method Using Specimens Simulating the Rock at the c0009 Site International-presentation

    JPG International Conference on a New Perspective of Great Earthquakes along Subduction Zones in KOCHI　2012/02

  184. Determination of Stress State in Deep Subsea Formation by Combination of Hydrofracturing Test and Core Analysis: A Case Study in the Integrated Ocean Drilling Program (IODP) Expedition 319 International-presentation

    AGU Fall Meeting　2010/12/13

  185. フラクチャリングによる未固結地層応力評価法の検討

    第2回メタンハイドレート総合シンポジウム　2010/12/02

  186. 微小地震に基づく貯留層内の圧力伝播挙動評価方の客観性向上に関する研究

    日本地熱学会22年度学術講演会　2010/11/26

  187. Laboratory Study on Hydraulic Fracturing in Unconsolidated Sands International-presentation

    International Symposium on Methane Hydrate Resources from Mallik to Nankai Trough　2010/11/17

  188. 堆積軟岩層を対象としたフラクチャリング挙動の可視化に関する研究

    JOGMEC-TRCウィーク2010　2010/11/08

  189. Deep Rock Stress Measurement by Hydraulic Fracturing Method Taking Account of System Compliance Effect International-presentation

    The 5th International Symposium of In-situ Rock Stress　2010/08/25

  190. Measurement of Pressure and Flow Distribution in Fractured Geothermal Reservoirs at Few Km Deep International-presentation

    G-COE Symposium 2010 Dynamic Earth and Heterogeneous Structure　2010/07/15

  191. CO2地中貯留層からの原位置反応法による漏洩修復と数値シミュレーションによる検討

    平成22年度石油技術協会春季講演会　2010/06/09

  192. 未固結地層フラクチャリング模擬実験のX線CTによる可視化

    平成22年度石油技術協会春季講演会　2010/06/09

  193. 大水深海底下の地層を対象にしたフラクチャリング技術

    資源・素材学会平成22年度春季大会　2010/04/01

  194. Proposed Concept of In-situ Reaction Barrier to Remedy Leakage from Reservoirs of Geological CO2 Storage International-presentation

    The 2nd International Symposium of Experimental-Integrated Computational Chemistry on Multiscale Fluidics　2010/02/24

  195. 未固結地層フラクチャリング挙動解明のための実験的アプローチ

    第1回メタンハイドレート総合シンポジウム　2010/02/16

  196. A Preliminary Result of Stress Orientation Obtained from Drilling Induced Fractures and Borehole Breakouts at Site C0009 of Expedition 319, NanTroSEIZE International-presentation

    EOS Trans. AGU, Fall Meet. Suppl.,　2009/12

  197. Downhole Hydrologic Testing in the Kumano Basin and Underlying Sediments: Results from NanTroSEIZE Expedition 319 International-presentation

    EOS Trans. AGU, Fall Meet. Suppl.,　2009/12

  198. Hydraulic Fracture Measurements at Site C0009 of IODP Expedition 319, NanTroSEIZE International-presentation

    EOS Trans. AGU, Fall Meet. Suppl.,　2009/12

  199. In Situ Stress and Deformation Patterns across the Nankai Kumano Basin and Forearc: Results from IODP Expedition 319 International-presentation

    EOS Trans. AGU, Fall Meet. Suppl.,　2009/12

  200. Stress and Pore Pressure Measurement in IODP Riser Drilling: An Example from Expedition 319, Kumano Basin offshore SW Honshu, Japan International-presentation

    EOS Trans. AGU, Fall Meet. Suppl.,　2009/12

  201. NanTroSEIZE第319次航海におけるライザー掘削孔でのMDT応力試験

    日本地震学会2009年秋季大会　2009/10

  202. NanTroSEIZE第319次航海におけるライザー掘削孔でのMDT水理試験

    日本地震学会2009年秋季大会　2009/10

  203. Outline of the In-situ Hydraulic Tests Using MDT Tool at 2.7 – 3.6 km below Sea Level in the First Riser Hole on the NanTroSEIZE Operation International-presentation

    the 15th Formation Evaluation Symposium of Japan　2009/09

  204. Outline of the In-situ Stress Tests Using MDT Tool at 2.7 – 3.6 km below Sea Level in the First Riser Hole on the NanTroSEIZE Operation International-presentation

    the 15th Formation Evaluation Symposium of Japan　2009/09

  205. Overview of NanTroSEIZE Rise Logging: Operational Planning and Reality International-presentation

    the 15th Formation Evaluation Symposium of Japan　2009/09

  206. キロメートル級深度における地殻応力計測の課題と解決策

    日本資源素材学会秋季大会　2009/09

  207. Laboratory Test of Hydraulic Fracturing in Unconsolidated Deformable Rocks International-presentation

    4th Biot Conf. on Poromechanics　2009/06

  208. 未固結砂層の水圧破砕挙動を模擬する室内実験

    平成21年度石油技術協会春季講演会　2009/06

  209. CO2地中貯留層からの漏洩修復法の検討

    日本地球惑星科学連合2009年大会　2009/05

  210. 微小地震による流路構造評価法の高度化

    藤村修一郎, 伊藤高敏, 海江田秀志

    日本地熱学会平成１９年度学術講演会　2007/11/28

  211. 未固結層に対するフラクチャリング室内実験

    五十嵐哲, 伊藤高敏, 鈴木清史, 長久保定雄, 松澤真樹, 山本晃司

    平成１９年度石油技術協会春季講演会　2007/06/05

  212. AEによる貯留層内圧力と流路構造評価−勇払油ガス田でのケーススタディ−

    伊藤高敏, 藤村修一郎, 林一夫, 手塚和彦

    平成１９年度石油技術協会春季講演会　2007/06/05

  213. き裂面加熱に伴う周囲岩体の熱膨張によるき裂内流動性変化の室内実験による検討

    伊藤高敏, 関根孝太郎, 山本晃司, 伊藤久男, 小村健太朗, 加藤春實, 田中博

    日本地球惑星科学連合2007年大会　2007/05/19

  214. 最大応力計測問題を解決する高剛性型水破砕地殻応力計測法（BABHY方式）の開発

    伊藤高敏, 関根孝太郎, 伊藤久男, 小村健太朗, 加藤春實, 田中博

    日本材料学会第56期学術講演会　2007/05/19

  215. 松代町におけるBABHY式水圧破砕法による地殻応力計測試験

    伊藤高敏, 関根孝太郎, 山本晃司, 伊藤久男, 小村健太朗, 加藤春實, 田中博

    資源・素材学会平成１９年度春季大会　2007/03/29

  216. 大深度地殻応力計測を目的としたBABHY式水圧破砕法とその実用化

    伊藤高敏, 伊藤久男, 小村健太朗, 田中博, 加藤春實, 狩野嘉昭

    第３７回岩盤力学に関するシンポジウム　2007/01/10

  217. Spatial variation in stress state in the source region of Orkeny earthqauke (M5.5) based on analyses of the ICDP-DSeis borehole cores

    Yabe, Y., Ishida, A., Sugimura, K., Kanematsu, M., Higashi, M., Yoshida, S., Ito, T., Funato, A., Watson, B., Durrheim, R., Liebenberg, B. and Ogasawara, H.

    JpGU meeting 2019　2019/05/26

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Industrial Property Rights 2

  1. 地殻応力測定方法

    伊藤 高敏, 玉川 哲也

    特許第6883811号

    Property Type: Patent

  2. 地殻応力測定法

    伊藤高敏, 手塚和彦, 玉川哲也

    特許第6332653号

    Property Type: Patent

Research Projects 31

  1. 既存コアとコア変形法による東北・北海道の地殻応力マップの生成と地熱開発への応用

    伊藤 高敏

    Offer Organization: 日本学術振興会

    System: 科学研究費助成事業

    Category: 基盤研究(C)

    Institution: 東北大学

    2021/04/01 - 2024/03/31

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    JOGMEC（（独）石油天然ガス・金属鉱物資源機構）は、地熱資源ポテンシャルの評価を目的とする調査を東北・北海道で2017年から実施しており、ヒートホールと呼ばれる調査井を深度1000m程度まで掘削して全深度のコアが採取されている。そこでJOGMECと交渉の上、東北大学に近い八幡平地域のヒートホール（A井と呼ぶ）のコアを一昨年に入手した。続いて昨年には、同地域の別の２カ所で掘削されたヒートホール（BおよびC井と呼ぶ）の深度約1000～1400ｍの範囲で採取されたコアを入手した。これらのコアの直径分布を測定し、その結果とコア変形法によってコア直交面内の地殻応力差を評価する作業を進めている。また、後者のBおよびC井では、一部の深度でディスキングつまりコアが直径方向に割れて薄い円盤になる現象が起こっていた。この現象は地殻応力状態を表す１つの指標とされ、坑井軸方向と直交方向の地殻応力差が極端に大きい場合に起こると理解されている。しかし、1000mを越える大きな深度でディスキングが起こる原因は明らかではない。そこで、ディスキング現象とコア変形情報を組み合わせることで地殻応力状態を評価する解析を進めている。一方、コア形状から地殻応力差を求める際には、コアのヤング率が必要となる。その測定を行うには、コアから円柱試験片を切り出し、それで一軸圧縮試験を行うという煩雑で時間を要する作業が必要となる。また、このことが原理的には非常にシンプルなコア変形法を煩雑にする要因となっている。そこで、より簡便にコアのヤング率を測定する方法を考案して検証した。これによれば、コア表面にひずみゲージを貼り付けるだけで、非破壊で測定することが可能となる。今後は、それを実行するための測定システムを構築し、これまで入手したコアに適用していく。

  2. Study on quantitative evaluation of fault activity for energy resource development

    Ito Takatoshi

    Offer Organization: Japan Society for the Promotion of Science

    System: Grants-in-Aid for Scientific Research

    Category: Grant-in-Aid for Scientific Research (B)

    Institution: Tohoku University

    2016/04/01 - 2020/03/31

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    Fracturing is a key technique for energy source industries to create fractures by injecting massive fluid into rock. We examined by numerical simulations why felt earthquakes are triggered by the fracturing. As a result, we found that when injected fluid propagates to raise pore pressure in a preexisting fault even by the MPa order, the raised pressure can generate dynamic slip of fault in area of the km2 order. However, such large dynamic slip of fault requires two conditions that friction coefficient of fault plane decreases with increasing slip velocity, and the fault is subjected to a large shear stress at critical level. The slip velocity dependency of friction coefficient and the stress state can be measured. This means that we can predict the felt earthquake possibility due to fracturing from those measured frictional characteristics and stress values.

  3. Experimental study of fracture tip screen-out with aid of X-ray CT considering its application to fracture control

    ITO Takatoshi, YAMAMOTO KOJI

    Offer Organization: Japan Society for the Promotion of Science

    System: Grants-in-Aid for Scientific Research

    Category: Grant-in-Aid for Challenging Exploratory Research

    Institution: Tohoku University

    2016/04/01 - 2018/03/31

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    We succeeded in reproducing the screenout phenomenon which is a problem in the fracturing technique indispensable for oil and natural gas production by laboratory experiments and visualizing the fracture behavior with the CT scanner. To this end, by using a soft material, fracture has become possible to open to a size that can be visualized even with a small test specimen, and by using a pressure vessel that well combines CFRP and engineering plastic with excellent X-ray transparency, it has become possible to apply any axisymmetric compressive stresses to a cylindrical specimen. Moreover, it has been found that the fluid to which barium sulfate was added is effective for observation of flow and clogging at fracture tip.

  4. Development of Deep Rock Stress Tester Based upon Hydraulic Fracturing and Diametrical Core Deformation Analysis

    ITO Takatoshi, SHIMIZU Hiroyuki, LIN Weiren, FUNATO Akio, NAYUKI Toshinori, KATO Kazumasa

    Offer Organization: Japan Society for the Promotion of Science

    System: Grants-in-Aid for Scientific Research

    Category: Grant-in-Aid for Scientific Research (A)

    Institution: Tohoku University

    2012/04/01 - 2015/03/31

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    We are developing new methods based upon hydraulic fracturing (HF), which allow us to measure in-situ stress at few km deep. It is assumed here that a drill string containing a wireline retrievable core barrel assembly has been set in the borehole in advance. The tool is conveyed on a wireline through the drill string, while the outer barrel remains at the bottom of the borehole. This way contributes greatly to avoid the risk of trouble occurring in boreholes such as the tool getting stuck. Then the HF test is carried out in a short hole additionally-drilled at the bottom of the original borehole, which is referred to the baby hole. The core retrieved from the baby hole can be applied to the Diametrical Core Deformation Analysis, DCDA, and we can have additional information on stress state independently of HF. By combining those data obtained from HF and DCDA, we can validate the estimated magnitude and azimuth of the in-situ stresses.

  5. Downhole experiments for in situ state and property assessment of seismogenic processes

    KINOSHITA Masataka, ITO Hisao, LIN Weiren, ITO Takatoshi, KANO Yasuyuki, ARAKI Eiichiro, YAMAOKA Koshun

    Offer Organization: Japan Society for the Promotion of Science

    System: Grants-in-Aid for Scientific Research

    Category: Grant-in-Aid for Scientific Research on Innovative Areas (Research in a proposed research area)

    Institution: Japan Agency for Marine-Earth Science and Technology

    2009/07/23 - 2014/03/31

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    Various experiments were conducted in order to assess insitu state and property of the seismogenic processes of subduction zone earthquakes. At Nankai Trough, insitu stresses were estimated through core measurements, resistivity-image logging, hydro-fracturing, vertical seismic profiling, etc., all of which show maximum horizontal compression parallel to the plate conversion. Borehole observatory data suggest that the temperature at the mega-splay fault at 5000 m below sea floor is 130-150 degC. At Japan Trtench, stress drop in the shallow portion was detected after the 3.11 Tohoku event. Insitu temperature monitoring at the fault zone revealed only +0.3degC increase, suggesting a very low friction (<0.1) during the fault slip. These are consistent with a large slip inferred along the shallow fault zone.

  6. Development of the method to remedy leakage from geological CO2 reservoir using CO2 reactive grout

    ITO Takatoshi, SEKINE Kotaro, SATO Akira, TOSHA Toshiyuki

    Offer Organization: Japan Society for the Promotion of Science

    System: Grants-in-Aid for Scientific Research

    Category: Grant-in-Aid for Scientific Research (B)

    Institution: Tohoku University

    2009 - 2011

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    In order to remedy CO_2 leakage through pre-existing and/or induced fractures from storage reservoirs, we studied a concept to use an aqueous solution. The solution will have a sufficiently-low viscosity for passing through even small aperture, and it will not impact formation permeability as long as the solution is left as it is. When the solution encounters dissolved CO_2, precipitation will occur due to chemical reaction. As a result, the permeability will be reduced by filling the pores and fractures in the rocks with the precipitates. We demonstrated first this idea through laboratory experiments simulating subsurface condition at 1000 m deep, i. e. 10 MPa and 40 deg. C. The results show that the present method led to a 99 %permeability reduction in a glass-bead artificial rock even its initially-high permeability of few darcy. Such reduction of permeability was reproduced successfully by the non-isothermal reactive geochemical transport program TOUGHREACT. Based upon these success, the present method was applied by numerical modeling to a 2-D caprock-aquifer system under field physical and chemical conditions. The results show that the precipitates were produced and they filled up pores around outlet of the leakage path so sufficiently that the CO_2 migration was blocked, and the condition was confirmed stable over a long time.

  7. メタンハイドレート開発のためのCO2ハイドレートを利用した浸透特性改質の研究

    伊藤 高敏

    Offer Organization: 日本学術振興会

    System: 科学研究費助成事業

    Category: 挑戦的萌芽研究

    Institution: 東北大学

    2009 - 2010

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    日本近海の深海底面下にあるメタンハイドレート(MH)が天然ガス代替エネルギーとして期待されている.MH層にフラクチャーを導入できれば,刺激の負荷とメタンガスの生産を効率よく実施できるはずである.しかし,MH層ではフラクチャー表面からの逸水が大きく,フラクチャーを十分に大きくすることが容易ではないことが予想される.一方,MHが存在する温度・圧力環境ではCO2もハイドレート化を起こす.本研究では、この性質を利用してフラクチャー面からの逸水を抑制する可能性を検討した.昨年度には,噴霧ノズルを用いることで微粒状のCO2を分散させた水(CO2エマルション)を作成できること,また,そのエマルションを適当な温度・圧力環境に置くことでCO2ハイドレートが形成され,攪拌を行えば十分間程度の短い時間でハイドレートの形成が起こることを明らかにした.それを踏まえて本年度では,エマルションを多孔質体に圧入したときの挙動を調べる室内実験を行った.そこで,圧入に必要な量のエマルションを作成するための装置,ならびに,そのエマルションを円柱状多孔質体に開けた坑井に圧入するための装置を作製した.実験の結果,水を流しただけでは何も変化が起きなかったのに対して,エマルションを流した場合には,攪拌や保持時間を要すことなく,流量一定の条件でも注入圧が徐々に大きくなっていくことがわかった.この現象は,発生したCO2ハイドレートが多孔質体の間隙を埋め,浸透率を低下させたことで起きたものと考えられる.これらのことから,CO2ハイドレートによってフラクチャー面からの逸水を抑制できる可能性が明らかとなった.

  8. Establishment of design methodology of EIMY : Experimental approach at Iwase Yumoto

    NIITSUMA Hiroaki, ASANUMA Hiroshi, MORIYA Hirokazu, ITO Takatoshi, MURAOKA Hirofumi, SOMA Nobukazu

    Offer Organization: Japan Society for the Promotion of Science

    System: Grants-in-Aid for Scientific Research

    Category: Grant-in-Aid for Scientific Research (A)

    Institution: Tohoku University

    2006 - 2008

  9. CO2地中固定のための人工バリアー

    伊藤 高敏, 関根 孝太郎

    Offer Organization: 日本学術振興会

    System: 科学研究費助成事業

    Category: 萌芽研究

    Institution: 東北大学

    2006 - 2007

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    地球温暖化抑制のため、火力発電所等の排ガスから分離・回収したCO2を,地下深度1km前後にあって,間隙率の比較的大きな岩石からなる地下帯水層に圧入して溶解・固定化するという方法が検討されている.また,この方法では,浸透性が小さい天然の構造性バリアー,すなわちキャップロックが存在することを前提とし,その下部にCO2を圧入することになっている.しかし,地殻活動が盛んな日本では,そのように健全で広大なキャップロックがある場所は限られている.そこで本研究では,現位置反応法で形成した人工バリアーによってキャップロックの欠損部を覆い,また,断層等の移動経路を遮断してCO2の漏洩を防止するという,従来にない新技術を開発する.この目的を達成するために本年度は,以下のことを実施した.まず昨年度の実験結果を再検討した結果,模擬岩石の浸透率を計測する際の差圧の測定方法に問題があって計測値に大きな誤差を含む可能性のあることが判明した.そこで,高圧環境下で作動する高精度の差圧計を導入し,さらに,模擬岩石内部の流れが均一になるような工夫を新たに加えることで,その問題点を解決した.また,CO2と反応する溶液(反応性グラウト)の新たな候補として水ガラス溶液を用いて実験を行った結果,昨年度に用いたCa (OH)2水溶液よりも粘性が十分小さい上に現位置反応による浸透性低下量も大きく,実用に十分適するものと判断された.

  10. 最大応力計測問題を打開する水圧破砕法国際スタンダードの構築と検証

    伊藤 高敏, 関根 孝太郎, 伊藤 久男, 小村 健太朗

    Offer Organization: 日本学術振興会

    System: 科学研究費助成事業

    Institution: 東北大学

    2006 - 2007

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    水圧破砕法は,km級の大深度における地殻応力の現位置計測を可能とする唯一の実用的手段として従来から広く用いられてきた.しかし,この方法では,坑井直交面内における最大応力を評価する要領に致命的な欠陥のあることが最近明らかになっている.その原因は,従来の仮定に反し,(a)残留き裂開口幅の存在によって,き裂の開口以前から坑井水圧がき裂内に浸入してしまうこと,(b)加圧システムのコンプライアンスC(システム内の水圧を単位量だけ増加させるのに必要な水の体積,換言すると剛性の逆数)が大きすぎるために,き裂開口の影響が坑井水圧の変化挙動に現れにくいことにある.これらを考慮して大深度での計測を可能にすべく我々は,坑井底部に直径の小さい試験孔(以下,ベビー孔)を新たに掘削して,その中で水圧破砕を実施するという新方式(Baby Borehole Hydro-fracturing, BABHY(ベイビー方式と呼ぶ))を提案した.その実用化を図るために本年度には,当初計画の通りにポンプユニットの製作に成功し,そして,それを組み込んだ,深度1キロまでの測定に耐える地殻応力測定装置の開発に成功した.さらに、地表から掘削された鉛直井に同装置を適用して,深度811mでの実証試験に成功した.また,同フィールド試験で用いたパッカー装置と大型試験片(700×700×1000mm3)による室内水圧破砕実験を実施した,圧力データと模擬地殻応力の関係が,我々の提案する理論(1/2理論と命名)通りであることを再検証した.

  11. A New Strategy and Its Verification for In-situ Measurements of the Maximum and Minimum Stresses at Deep Depths by Hydraulic Fracturing

    ITO Takatoshi, SEKINE Kotaro, ITO Hisao, OMURA Kentaro

    Offer Organization: Japan Society for the Promotion of Science

    System: Grants-in-Aid for Scientific Research

    Category: Grant-in-Aid for Scientific Research (B)

    Institution: Tohoku University

    2006 - 2007

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    Hydraulic fracturing is suitable in principle for in-situ stress measurements at deep depths. However, as has been pointed out recently, its current testing systems and procedure involve essential problems which have to be solved before putting the principle into practice. The most serious problem is associated with the hydraulic compliance of fracturing systems. For measuring the reopening pressure, it is necessary to use the fracturing system with sufficiently small compliance. If not, there is no way to estimate the maximum horizontal stress from the reopening pressure assuming a vertical borehole, even though the maximum horizontal stress is the greatest concern in the stress measurement. This limitation makes it difficult to apply hydraulic fracturing for the stress measurement, because the compliance of the conventional system is so large. Taking into account of these facts, we have proposed recently a new method which will allow us to measure both of the maximum and minimum stresses by in-situ tests of hydraulic fracturing at a depth greater than a few km. We have proceeded to test and verify the method step by step so far through laboratory and field experiments using a borehole of 80 m in depth drilled from the ground surface at Matsushiro. Finally, we succeeded to apply the method to an in-situ test of hydraulic fracturing at a depth of 811 m in a vertical borehole drilled from the ground surface at Tazawako.

  12. マグマ内揮発性物質による火道内部の増圧過程の解明

    西村 太志, 吉田 武義, 中村 美千彦, 伊藤 高敏, 中嶋 悟, 寅丸 敦志

    Offer Organization: 日本学術振興会

    System: 科学研究費助成事業

    Category: 特定領域研究

    Institution: 東北大学

    2002 - 2006

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    本研究は,火山爆発の発生前のマグマの状態と爆発的噴火プロセスの関係を明らかにすることを目的とし,これら爆発的噴火の準備に関する一連のプロセスを,発泡過程,脱ガス過程,火道開口・閉塞過程などの素過程に分解し,主に,実験的,理論的な研究を進めた.また,これらの過程を統合したモデルの構築や,噴出物の複数解析や他現象との比較検討に基づき,火道内の増圧過程やマグマプロセスを調べた.脱ガス過程について,主に室内実験の結果から以下のことが明らかとなった.マグマ内に剪断破壊により生じた通路や気泡連結による通路が生じている場合,浸透脱ガス流とともに気泡吸収がマグマ内で生じ,マグマ内に気泡の無い層を形成する可能性がある.また,発泡が十分進んでいない深い領域でも,剪断応力が大きい火道壁近傍などでは気泡が十分連結するため,脱ガスが進行することがある.火道や亀裂の閉塞過程の実験によって,高温マグマの貫入時には熱により周辺岩体が大きく変形し通路を閉塞することがあること,火山下の熱水流動による火山ガラスの水和・変質・溶脱過程により火山体を構成する媒質の浸透率が3桁以上変化すること,が明らかとなった.また,カルデラ崩壊とプルトン貫入の関係をもとに,カルデラの火道形成過程を考察した.マグマ上昇モデルの数値計算から,爆発的噴火前には,マグマが浅部に近づくにつれ揮発性物質の発泡によるマグマの体積増のため地殻変動が急速に進行するのに対し,非爆発的噴火の前には,脱ガスによるマグマ体積の減少が起こるため,急速な地殻変動は観測されないことが明らかとなった.火山噴出物解析を行い,火山灰の火山ガラスの特徴と,地震観測等の力学的条件から区別される桜島の爆発的噴火様式の関係を調べた.また,火山噴出物の水の実効的な拡散係数,色変化特性,浸透率測定から,発泡のその場観測などからマグマ上昇過程に関連した時間スケールを議論した.

  13. Thermoelastically-induced fracture permeability enhancement associated with cold fluid injection

    ITO Takatoshi

    Offer Organization: Japan Society for the Promotion of Science

    System: Grants-in-Aid for Scientific Research

    Category: Grant-in-Aid for Scientific Research (C)

    Institution: Tohoku University

    2003 - 2004

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    When cold fluid flows into fractures within a rock, the rock cools down and the cooling causes thermal contraction of the rock around the fractures. As a result, the fractures are likely to open and to be more permeable. We analyze the effect of remote compressive stresses on fracture opening associated with cold fluid flow by using a 2D FEM code. The results show that the fracture opening will be suppressed by remote compressive stresses, but even in such a condition, the considerable increase in fracture opening and permeability will appear when the temperature of injected fluid is smaller than a critical value T_c. This value is given as a function of remote compressive stresses, fracture pressure, and elastic properties of rock. In order to verify the theoretical prediction, we carried out laboratory experiments using a cylindrical specimen. There exists an artificial fracture passing through the specimen in the axial direction, and the experiments were proceeded as follows ; (i)apply a confining stress to the specimen, (ii)elevate the specimen's temperature to a certain level, (iii)inject cold water into the fracture by a constant pressure, and measure the injection rate, (iv) estimate the fracture permeability from the measured injection rate. From the results of experiments, we confirmed that the fracture permeability increases gradually with decreasing the injection temperature, and the increasing rate changes dramatically when the injection temperature becomes lower than the critical value T_c as theoretically predicted.

  14. Theoretical and Experimental Study on Physical Mechanism behind the Formation of Drilling Induced Tensile Wall Fracture (DTF) for Borehole Stabilization

    ITO Takatoshi, YAMAMOTO Koji, HAYASHI Kazuo

    Offer Organization: Japan Society for the Promotion of Science

    System: Grants-in-Aid for Scientific Research

    Category: Grant-in-Aid for Scientific Research (C)

    Institution: Tohoku University

    2001 - 2002

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    The advanced logging tools such as FMI and BHTV/UBI tools allow us to see the structure of borehole wall in very detail. The results show that there appear frequently the multiple fractures in an en-echelon pattern on opposite sides of the borehole wall. They are called as the Drilling Induced Tensife Wall Fractures, DTF for short. It is known that they are formed in the borehole wall while drilling, however, it has been not clarified yet how they are formed. In this paper, we investigate the mechanism behind the formation or DTF. To this end, we developed theoreticai models to estimate the critical borehole pressure necessary to initiate inclined fractures at the borehole wall, P_<frac>, and that necessary to link them near the borheole wall, P_<link>. The models are taken into account of thermal stress caused by the difference in temperature of rock and borehole fluid, Dt. Our modeling shows that P_<frac> and P_<link> are changed with borehole orientation, in-situ stresses and Dt. P_<link> can become to be larger than P_<frac> DTF may be observed in such a case. Note that DTF has a small fracture length along the borehole wall suggests a small fracture opening at the borehole wall compared to the opening of large, axial fractures that occur once the small fractures have linked up. If the fracture opening is small, the opening could be sealed with the drilling mud, and significant circulation loss could be prevented. This may be the reason why there was not any indication of lost circulation at the depths where DTF were observed. To verify the present models, laboratory experiments were performed on the PMMA cubical specimens under biaxial compressions. The specimens are transparent, and it allows us to see directly the fracture formation on borehole wall. The borehole was cooled down by injection of liquid nitrogen, and the cooling caused thermal tensile stress to induce DTF on the borehole wall. The experimental results agree well with the model prediction.

  15. In-situ stress monitoring based on variation in electrical property of rock associated with micro-crack closure

    ITO Takatoshi, SAITO Hiroyuki, HAYASHI Kazuo

    Offer Organization: Japan Society for the Promotion of Science

    System: Grants-in-Aid for Scientific Research

    Category: Grant-in-Aid for Scientific Research (C)

    Institution: Tohoku University

    1999 - 2000

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    It is known that electrical resistivity of rocks are defined as a function of porosity, pore inter-connectivity and resistivity of pore fluid. Resistivity of rocks changes with also stress as has been shown experimentally by Glover et al.(1994). Such dependency of resistivity on stress is likely, since porosity and pore inter-connectivity should change with stress condition. On the other hand, when a borehole is drilled into a formation, a stress disturbance is introduced in the vicinity of the borehole. As inferred from the relationship between resistivity and stress, the stress disturbance possibly induces an additional disturbance in resistivity around the borehole. The resistivity disturbance should be a function of remote stresses as same as the stress disturbance. Therefore, it may be possible to estimate remote stresses from resistivity distribution around the borehole, if we can measure the resistivity distribution somehow. To accomplish this idea, first we conduct laboratory experiments to measure resistivity of rock under uniaxial loading condition by using a cylindrical specimen. Then we examine how the specimen's resistivity in axial and transverse directions of the specimen changes with axial loading. Based on these results, we propose a new method to estimate in-situ stress state from resistivity distribution in the vicinity of borehole.

  16. Research on Surface Modification System by Using a Cavitating Jet

    SOYAMA Hitoshi, URANISHI Kazuo, WATANABE Yutaka, ITO Takatoshi

    Offer Organization: Japan Society for the Promotion of Science

    System: Grants-in-Aid for Scientific Research

    Category: Grant-in-Aid for Scientific Research (B).

    Institution: Tohoku University

    1998 - 2000

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    1.Surface modification system has been developed considering scale effects of nozzle diameter. Diameter of nozzle is from 0.4mm to 1.9mm. 2.Cavitation impacts were measured by a PVDF transducer for various cavitating conditions. When the nozzle diameter was increased, the frequencies of the cavitation impacts were not only increased but also the intensity of the cavitation impacts increased. Reducing air contents ration in the test water also increased the cavitation impacts. 3.Optimum peening time or optimum scanning speed was demonstrated by measuring hardness or residual stress. The cavitating jet can introduced compressive residual stress in the surface of the materials. The value of the compression was saturated at certain processing time or speed. In case of the improvement of the corrosion resistance by using a cavitating jet, optimum processing time was obtained by the relation between the potential by means of an electrochemical method and the processing time. 4.Regarding test liquid of the cavitating jet, several liquids ware tested changing with pH.Suitable test liquids for iron were clarified referring Pourbaix diagram of iron. 5.Peening for gears and specimens with a notch was carried out. It was revealed that the peened surface by a cavitating jet was very smooth comparing with that of the shot peening. The cavitating jet can also introduce the compressive residual stress into hard materials such as tool alloy SKD61. 6.In order to demonstrate improvement of fatigue strength by suing a cavitating jet, a rotating bending fatigue test was carried out. It was shown that the cavitating jet could improve the fatigue strength. It was also revealed that the cavitating jet could improve the corrosion resistance about 30% by means of an electrochemical method.

  17. Estimating Stress at Great Depth from Borehole Breakout

    HAYASHI Kazuo, SONG Insun, SAITO Hiroyuki, ITO Takatoshi, HAIMSON Bezalel

    Offer Organization: Japan Society for the Promotion of Science

    System: Grants-in-Aid for Scientific Research

    Category: Grant-in-Aid for international Scientific Research

    Institution: Tohoku University

    1997 - 1998

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    The objective of the present study is to clarify the mechanism of nucleation of borehole breakout and to examine the growth process of the borehole breakout, emphasizing the effect of the bottom of the borehole. Firstly, the characteristics of the three-dimensional elastoplastic stress field around the bottom were studied by FEM analysis, paying special attention to the singular stress field around the bottom. Then, a model of a pseudo two-dimensional stress field simulating the three-dimensional stress field was constructed, and the growth process was examined by using the pseudo stress field. The results are summarized as follows : 1) Near the bottom of the borehole, stress concentration takes place at a circumferential position that is different from that at a borehole section far from the bottom. The region of stress concentration is very localized. 2) Thus, for a rock that is insensitive to a local stress field in fracture nucleation, borehole break out is not formed at the bottom of borehole. 3) Variation of the stress field with respect to the distance between the bottom and the observation position, can be seen as the time variation of stress at a fixed depth during drilling. The geometry of borehole breakout calculated by following exactly the loading path just mentioned is almost the same as that estimated by two-dimensional approach. 4) Therefore, the breakout can be considered to be formed on the wall of a cylindrical cavity in an elastoplastic medium subjected to a monotonically increasing load at infinity. 5) The width of the breakout is almost the same as that estimated by purely elastic stress state, indicating the validity of the hypothesis proposed by Haimson et al. on the relationship between the width and the far field stress.

  18. Estimation of In Situ Rock Stress at a Great Depth by Means of Drilling Induced Tensile Fractures

    HAYASHI Kazuo, OKABE Takashi, ITO Takatoshi

    Offer Organization: Japan Society for the Promotion of Science

    System: Grants-in-Aid for Scientific Research

    Category: Grant-in-Aid for Scientific Research (B)

    Institution: Tohoku University

    1996 - 1998

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    The main objective of the present project is the development a new technique estimating in situ stress in rock masses at great depths under high temperature and high confining pressure conditions, by taking advantages of drilling-induced tensile fractures (DTF). DTF is characterized by two factors, i.e. circumferential position of two macroscopic longitudinal fractures on the borehole wall and inclination of short cracks consisting of the macroscopic longitudinal fractures. Thus, at each depth range of a borehole, two sets of information are available for estimating stress state. Therefore, if there are more than three depth ranges with DTF's, it is possible in principle to set up more than six observation equations for six unknown stress components. Based on this fact, an inverse problem has been constructed, as well as the new technique for solving the inverse problem, where a statistical approach is employed to overcome the ambiguity due to the errors that are inevitably included in DTF data observed. Furthermore, a program code that is applicable for solving the inverse problem by using personal computers, has also been developed. Data of borehole breakout can also be incorporated in the new technique, if available. The validity has been confirmed by applying the technique to fictitious data sets that were constructed numerically. Finally, the new technique was applied to field DTF data obtained from three boreholes to demonstrate the applicability of the new technique to field data. The three boreholes are TG-2 of Yunomori HWR test site, HDR-2 of Hijiori HDR test site and RH-15 of British HDR test site. All these trials are satisfactory.

  19. 微小き裂閉口に伴う岩体の電気特性変化を利用した地殻応力モニタリング

    伊藤 高敏

    Offer Organization: 日本学術振興会

    System: 科学研究費助成事業

    Category: 奨励研究(A)

    Institution: 東北大学

    1997 - 1997

  20. 地下き裂開口挙動直接計測による地殻応力の高精度評価に関する基礎研究

    伊藤 高敏

    Offer Organization: 日本学術振興会

    System: 科学研究費助成事業

    Category: 奨励研究(A)

    Institution: 東北大学

    1996 - 1996

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    本研究では,パッカーを膨張させて縦き裂のあるボアホール壁面に押しつけることで壁面に圧力を負荷した際の壁面の周方向変位から,岩体の地殻応力(初期応力)を計測評価する新たな方法を検討した.このため,バッカー外周にとりつける周方向変位測定素子を試作した.試行錯誤の結果,同素子としては,ひずみゲージを絶縁性の材料で挟み込んだ構造で,また,パッカーが膨張して坑井壁面に押しつけられるまでに発生するひずみを極力除去するために,接着せず,浮かせてパッカー表面に取り付ける構造とするのがよいことがわかった.この測定素子を,本研究で新たに作成した室内実験用の小型パッカーに取り付け,その特性を模擬坑井を使って調べた.模擬坑井はアルミ製および天然の安山岩製の二種類で,坑井中心を通る対称面が分離できる構造をしており,その分離面をき裂面と見なし,地殻応力を模擬するために試験片側面に加えた圧縮応力と上記で測定したボアホール壁面の周方向ひずみの関係を調べた.この結果,上記測定法によれば,ボアホール壁面の周方向ひずみとパッカー膨張圧の関係が,昨年度の数値シミュレーションで明らかにしたようにき裂開口圧付近で大きく変化する現象を明確に捕らえられることがわかった.これにより,上記測定法によっていわゆるき裂開口圧を精度良く評価できることがわかった.また,測定された周方向ひずみとパッカー膨張圧の関係より,岩体の縦弾性係数とポアソン比を計測する方法を提案した.この方法を上記の実験結果に適用して弾性定数を求め,他の実験結果と比較した結果,両者が非常に良く一致していることがわかった.

  21. 電気容量型変位計の原理による地下き裂開口挙動評価のための基礎研究

    伊藤 高敏

    Offer Organization: 日本学術振興会

    System: 科学研究費助成事業

    Category: 奨励研究(A)

    Institution: 東北大学

    1995 - 1995

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    本研究では,パッカーを膨張させて縦き裂のあるボアホール壁面に押しつけることで壁面に圧力を負荷した際の壁面の周方向変位から,岩体の地殻応力(初期応力)を計測評価する新たな方法を検討した.このため,有限要素法によって壁面圧力によるボアホール変形挙動を解析した.また,ボアホール壁面の周方向変位を測定する具体的方法について実験的に検討した.得られた知見をまとめると次のようになる.(1)ボアホール壁面圧力S_Pが零の状態からの壁面上における周方向ひずみの増分Δε_θは,初めのうちはS_Pに対して線形に増加するが,き裂開口開始から両関係のこう配が変化する.(2)この傾向は,ボアホールに直交する平面内に作用する地殻応力の比S_1/S_2を1から3の範囲で種々変化させた結果についても同様であった.(3)よって,何らかの方法でΔε_θを測定できれば,測定して得られたΔε_θ vs S_P曲線のこう配の変化からき裂の開口開始を検出でき,き裂開口開始時のS_Pの大きさとしてき裂開口圧P_rの大きさを評価できる.さらに,その結果をき裂閉口圧等の通常の水圧破砕計測結果を組み合わせればS_1およびS_2それぞれの大きさを決定できる.(4)上記方法具体化のため,加圧中のボアホール壁面上の周方向ひずみを測定する装置を試作し,その性能をボアホールを鋼管で模擬した室内実験で評価した.この結果,当初予定していた電気容量型変位計の原理では測定が困難であることがわかった.そこで,ひずみゲージを基本とする素子を作成し,それを用いれば加圧中に周方向ひずみを測定できることを明らかにした.

  22. Stability of the Solidified Magma Region for Direct Utilization of Magma Energy

    HAYASHI Kazuo, ITO Takatoshi

    Offer Organization: Japan Society for the Promotion of Science

    System: Grants-in-Aid for Scientific Research

    Category: Grant-in-Aid for General Scientific Research (C)

    Institution: Tohoku University

    1994 - 1995

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    Stability of the solidified region for the direct extraction of energy from molten magma was examined from the view point of solid mechanics. Firstly, the constitutive law of the solidified magma was investigated, by using the Norton law to express the dependency of creep strain on stress, for the uni-axial stress-creep strain relation. With regard to the dependency of creep strain on time, the creep strain was set to be linear with respect to time as usually used in the secondary creep stage and the Arrhenius law is introduced to express the temperature dependency of creep strain. Based on the uni-axial stress-creep strain relation, the constitutive equation was constructed by employing the J_2 flow theory which utilized the second invariant of deviatric stress the creep potential. Three kinds of rock, i.e. granite, anorthosite and olivine, were introduced. As for the temperature condition, following two cases was considered. The first case is that convection of molten magma flow is very weak and thus the size of the solidified region is primarily determined by the solidus temperature. The second case is that the convection of magma is sufficiently strong so that the size of the solidified magma is almost determined by the heat balance between the heat extracted and the heat supplied by the convective magma from the outside of the solidified region. The temperature distribution was analyzed for the both cases and the stress distribution and the deformation were clarified, shedding light on the formation of fracture network within the solidified region, based on the constitutive equations and the temperature fields mentioned above. It was revealed that, for both of the two cases, olivine was the most potential candidate from the view point of formation of fracture network and anorthosite came next. Granite would not be appropriate for the direct extraction of magma energy.

  23. 地下き裂の力学特性を応用した地殻応力計測評価のための真のき裂開口圧計測法の開発

    伊藤 高敏

    Offer Organization: 日本学術振興会

    System: 科学研究費助成事業

    Category: 奨励研究(A)

    Institution: 東北大学

    1994 - 1994

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    本研究では,水圧破砕で作成したき裂が再加圧によって開き始めるときのボアホール水圧(真のき裂開口圧)から地殻応力を評価することを目的として,一定圧入流量で再加圧した際のボアホール水圧一時間曲線が線形から非線形になるときのボアホール水圧(見かけのき裂開口圧)の情報から真のき裂開口圧を評価する方法を明らかにし,これを実フィールド実験によって検証した.得られた知見をまとめると次のようになる.(1)真のき裂開口圧と見かけのき裂開口圧の間に差が生じる主な原因は,き裂が開口したことによって増加する加圧体積の水圧に対する増加率(以下,き裂体積増加率と呼ぶ)の大きさにある.つまり,き裂が開口した直後では,き裂体積増加率があまり大きくないために,二つのき裂開口圧の間に差が生じてしまう.(2)ただし,有効加圧系体積と呼ぶ加圧系内の水の体積に相当する量を小さくすることによって,再加圧時のボアホール水圧一時間曲線に及ぼすき裂体積増加率の影響を大きくすることが可能である.この結果,有効加圧系体積が小さいほど,見かけのき裂開口圧は真のき裂開口圧に近づいて行く.(3)したがって,有効加圧系体積を十分小さい水圧破砕システムを用いれば,そのとき測定された見かけのき裂開口圧から真のき裂開口圧を近似的に評価することができる.さらに,き裂面垂直方向の地殻圧縮応力の大きさがき裂閉口圧を利用するなどして既知であるものとすると,その結果と真のき裂開口圧の測定結果からき裂線方向の地殻圧縮応力の大きさを評価できる.(5)なお,有効加圧系体積の大きさは,単純に図面上の幾何学的形状か評価される加圧系内の水の体積とは必ずしも一致せず,加圧系全体のコンプライアンスを考慮して評価しなければならない.

  24. 注水停止後の逸水に伴う地下き裂閉口特性を応用した地殻応力計測評価に関する研究

    伊藤 高敏

    Offer Organization: 日本学術振興会

    System: 科学研究費助成事業

    Category: 奨励研究(A)

    Institution: 東北大学

    1993 - 1993

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    本研究では、ボアホールと直交する横き裂が存在する場合を対象として、シャットイン後のき裂閉口挙動を解析し、シャットイン後のボアホール水圧降下曲線(シャットイン曲線)とき裂閉口挙動との関係を解明して、き裂閉口圧決定法を提案するとともに室内実験による検証を行った。この結果得られた知見をまとめると次のようになる。(1)ボアホールと直交し、かつ、ボアホール軸に対して軸対称な地殻圧縮応力を受ける横き裂を対象とし、シャットイン後のき裂閉口挙動を解析してシャットイン曲線を求め、それに及ぼす諸因子の影響について検討した。その結果、次のことがわかった。すなわち、ボアホール水圧の大きさがき裂面垂直方向の地殻圧縮応力の大きさに等しくなったとき、き裂全体が同時に閉じてしまう。また、シャットイン曲線の形状はき裂長さが変わってもほとんど変化しないが、逸水係数の影響は強く、逸水係数が大きくなるほどシャットイン曲線のこう配が大きくなる。また、逸水係数が同じでも、き裂閉口挙動の違いから、縦き裂の場合の方が横き裂の場合よりシャットイン曲線のこう配が全体的に大きくなる。(2)横き裂のシャットイン後の水圧降下には、シャットイン直後に起こるき裂進展が終了してからき裂が閉じるまでの段階およびき裂全体が閉じた以降の段階の各段階で、ボアホール水圧の時間変化率の逆数がボアホール水圧に比例するという特性がある。(3)上記の特性を利用すれば、き裂閉口圧を明確に決定できる。すなわち、シャットイン曲線をボアホール水圧の時間変化率の逆数とボアホール水圧との関係に整理し直し、それを二直線近似したときの二直線の好転を検出すれば、その交点のボアホール水圧として、き裂閉口圧が与えられる。

  25. 流体圧による地下き裂開口挙動特性を応用した地殼応力計測評価法に関する研究

    伊藤 高敏

    Offer Organization: 日本学術振興会

    System: 科学研究費助成事業

    Category: 奨励研究(A)

    Institution: 東北大学

    1992 - 1992

  26. 地下岩体の現位置通水特性の高精度計測評価法に関する研究

    林 一夫, 伊藤 高敏

    Offer Organization: 日本学術振興会

    System: 科学研究費助成事業

    Category: 重点領域研究

    Institution: 東北大学

    1992 - 1992

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    平成2年度では,従来圧力パルス試験のネックとなっていた圧送水の遷流の問題及び加圧系コンプライアンスの問題の2つの問題を解決した。平成3年度では,微細き裂の選択方位により生じる異方性の問題を解決した。計画の最終段階に当たる平成4年度では,圧力依存性の検討を行うことのできる方法を開発した。この方法は,基本的には,加圧区間水圧を一定に保ったときの,還流流量の応答を見るものである。まず,試験坑井の加圧区間に所要の一定圧力を負荷し保持したときの熱交換層内の流れを解析し,このときにパッカーエレメントを越えて試験坑井内に還流してくる水量の経時変化と通水特性との相関を定量的に明らかにした。次に,この相関を基準にして,フィールド計測データから,現位置通水特性を評価するための方法を開発した。具体的には,以下の手順で行う。ストラドルパッカーシステムを,ボアホールの所定深度にセットし,加圧区間を所要の設定圧に一定に保って加圧し,ボアホール内への還流流量の経時変化を計測する。これを保数時間軸に対しプロットし,時間が十分経過した部分で得られる直線部の傾きと,この直線部を還流流量が零となる所へ外挿したときの時刻を求める。設定圧に対する通水特性は,この傾きと時刻から,本研究で得た算定式を用いて求めることができる。この手順による現位置計測及び評価を,加圧区間水圧の設定値を種々変化させて実施することにより,通水特性の貯留層圧依存性を把握することができる。前述の算定式には,ストラドルパッカーシステムの加圧区間長さ,パッカーエレメント長さ及びボアホール半径の諸寸法によって決まる係数が入っているが,本研究では,この係数の寸法依存性に関するデータも明らかにしており,従って,本方法はパッカーシステムの寸法によらず用いることができる。また,本方法では,加圧系内の水圧の経時変化はないので,コンプライアンスの影響を受けない。

  27. Pressure Data in 3-D Hydrofrac Stress Measurement

    HAYASHI Kazuo, ITO Takatoshi, LEE M. Y., ZHAO Z., HAIMSON Bezarel C.

    Offer Organization: Japan Society for the Promotion of Science

    System: Grants-in-Aid for Scientific Research

    Category: Grant-in-Aid for international Scientific Research

    Institution: Tohoku University

    1991 - 1992

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    For in situ measurement of tectonic stress in the deep earth's crust, hydraulic fracturing technique is most promising. In the present project, physical background of the pressure data which are used in the technique to evaluate the tectonic stresses are clarified and several new methods for determining the pressure data from pressure-time records during hydraulic fracturing are proposed. Firstly, we introduced a new criterion for initiation of a crack from a wellbore surface subjected to a fluid pressure and succeeded to explain quantitatively the dependency of breakdown pressure on the wellbore diameter and also on the injection flow rate to show that the breakdown pressure can be useful pressure data bringing the information on the stress component acting parallel to the crack surface. Secondly, we analyzed, based on the fracture mechanics, closure process of the crack after shut in to find that the closure process consists of three stages : from cessation of crack growth until crack tip closure, from just after crack tip closure until complete crack closure, and from just after complete crack closure until the test is stopped. It is revealed that the inverse of the wellbore pressure decrease rate after shut-in is linear with respect to the fluid pressure in the first and the last stages. It is also shown that the far field minimum compressive stress can be determined on the basis of these characteristics. Finally, we also analyzed the reopening behavior of the crack during repressurization cycles, based on fracture mechanics and fluid dynamics. It is found that the so-called reopening pressure does not coincide the pressure at which the crack really opens. The so-called reopening pressure is highly dependent on the injection flow rate and approaches the magnitude of the compressive stress acting normally to the crack.

  28. マグマエネルギ-抽出のための地下システムの力学的安定性に関する固体力学的研究

    林 一夫, 伊藤 高敏

    Offer Organization: 日本学術振興会

    System: 科学研究費助成事業

    Category: 一般研究(C)

    Institution: 東北大学

    1991 - 1991

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    マグマからの直接熱抽出における地下熱抽出システムの坑井周囲に形成される固化域の挙動を解明した。まず、固化域、部分凝固域および溶融マグマ内の温度場の熱抽出に伴う過渡的な応答の解析を行い、温度分布の経時変化を求めるとともに、固化域の成長、さらに熱抽出停止時の固化域の消滅過程を検討した。次に、得られた温度場を用いて、クリ-プを考慮した応力解析を花崗岩質、カンラン岩質および斜長岩質マグマに対して実施し、各岩質に対する固化域の応力分布の特徴およびその経時変化の特徴を明かにした。さらに、この応力解析をもとに、各岩質のマグマエネルギ-直接抽出システムに対する適用性について、開放型システムにおける坑井近傍の破砕帯形成の観点から評価した。得られた知見を要約すると以下の通りである。1.閉鎖型システムにおいては、熱抽出開始後短時間(400ー500時間)で固化域の成長がほとんどなくなる。これに対し開放型システムでは、はるかに長時間(1500時間以上)にわたって成長を続けその半径は坑井半径の30倍以上に達する。2.閉鎖型は、熱抽出停止後約1日で固化域が消失するのに対し、開放型では、消失までに約30日以上を要し、従って緊急停止後復旧までの猶予時間を十分長く見込める。3.坑壁での応力を調べた結果、花崗岩質クリ-プ特性を有する場合には、常に大きな圧縮応力が作用し周方向の割れは極めて生じにくい。これに対し、カンラン岩質クリ-プ特性を有する場合には、約5km以浅で、坑壁で周方向に引張応力が作用する。斜長岩石の場合には、この両者の中間の傾向がみられる。以上から、花崗岩質、カンラン岩質、斜長岩質の三者の内、カンラン岩質が熱抽出に伴って坑井周辺に破砕帯を最も形成しやすい性質を有し、開放型システムに適しており、斜長岩がこれに次ぐことになる。これに対し、花崗岩質の場合は、開放型熱抽出システムには不向きである。

  29. 流体を内部に含むき裂の力学特性を応用した地殼応力計測法を確立するための基礎研究

    伊藤 高敏

    Offer Organization: 日本学術振興会

    System: 科学研究費助成事業

    Category: 奨励研究(A)

    Institution: 東北大学

    1991 - 1991

  30. Study on Evaluation of Hydraulic Properties of Rocks Competitive

    System: Grant-in-Aid for Scientific Research

    1989/04 -

  31. Study on In-situ Stress Evaluation Competitive

    System: Grant-in-Aid for Scientific Research

    1989/04 -

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Social Activities 1

  1. みやぎ県民大学

    2009/09/18 -

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    宮城県の県民を対象とする生涯学習活動支援の一環として講座「流れを科学する」の「地下のながれ」を担当

Other 11

  1. コア変形法による地殻応力評価法

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    地殻空間の利用ならびに地球物理に関わる諸現象の解明には地殻に作用する応力を定量的に評価できることは必要である。また、応力成分の内の水平面内に作用する最小値については、その評価手法が確立している。しかしながら、最大値については特に大深度に適用できる実用的手段は未だにない。本研究は、コアの変形を利用して、この課題解決を目指すものである。

  2. 大深度地殻応力の定量評価

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    海底掘削孔内での高精度・高忠実度な性能をもつ応力・歪・傾斜・地震等の計測を可能にするため、陸上掘削孔で共同試験観測を行い、IFREEおよび東北大学の持てる技術・ノウハウを集結して比較検討・評価を行うことを目的とする。

  3. 人工未固結堆積物試料内におけるフラクチャ形成・進展と流体挙動に関する実験

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    人工未固結堆積物試料内におけるフラクチャ形成・進展と流体挙動に関する実験

  4. 人工未固結堆積物試料内におけるフラクチャ形成・進展実験

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    人工未固結堆積物試料内におけるフラクチャ形成・進展実験

  5. 堆積軟岩層を対象にした応力環境評価技術の開発

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    堆積軟岩層を対象にした応力環境評価技術の開発

  6. AEに基づく葛根田地熱貯留層内の流体移動評価に関する研究

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    AEに基づく葛根田地熱貯留層内の流体移動評価に関する研究

  7. 深部地殻応力評価のためのBABHYシステムの開発に関する研究

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    深部地殻応力評価のためのBABHYシステムの開発に関する研究

  8. 火山噴火解明のためのマグマき裂進展に及ぼす熱応力の影響に関する研究

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    火山噴火解明のためのマグマき裂進展に及ぼす熱応力の影響に関する研究

  9. AEに基づく先進地熱貯留層内の圧力と流体移動マッピング技術に関する研究

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    AEに基づく先進地熱貯留層内の圧力と流体移動マッピング技術に関する研究

  10. 冷却に伴うき裂透水性の変化挙動に関する研究

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    冷却に伴うき裂透水性の変化挙動に関する研究

  11. 地下き裂の透水性と地殻応力との関係に関する研究

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    地下き裂の透水性と地殻応力との関係に関する研究

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