Project/Area Number |
05232101
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Research Category |
Grant-in-Aid for Scientific Research on Priority Areas
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Allocation Type | Single-year Grants |
Research Institution | Tohoku University |
Principal Investigator |
NAKATSUKA Katsuto (1995-1996) Tohoku Univ., Faculty of Engng, Prof., 工学部, 教授 (60005345)
高橋 秀明 (1993-1994) 東北大学, 工学部, 教授 (10005267)
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Co-Investigator(Kenkyū-buntansha) |
HASHIDA Toshiyuki Tohoku Univ., Faculty of Engng, Assoc.Prof., 工学部, 助教授 (40180814)
YAMASAKI Nakamichi Kochi Univ., Faculty of Science, Prof., 理学部, 教授 (50036589)
HAYASHI Kazuo Tohoku Univ., Institute of Fluid Science, Prof., 流体科学研究所, 教授 (30111256)
TAKAYASU Hideki Tohoku Univ., Graduate School of Info.Sci., Prof., 大学院・情報科学研究所, 教授 (00183062)
YUSA Yuki Kyoto Univ., Faculty of Science, Prof., 理学部, 教授 (90025403)
佐々 宏一 京都大学, 工学部, 教授 (40025953)
中塚 勝人 東北大学, 工学部, 教授 (60005345)
水田 義明 山口大学, 工学部, 教授 (20107733)
|
Project Period (FY) |
1993 – 1995
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Project Status |
Completed (Fiscal Year 1996)
|
Budget Amount *help |
¥45,500,000 (Direct Cost: ¥45,500,000)
Fiscal Year 1996: ¥3,000,000 (Direct Cost: ¥3,000,000)
Fiscal Year 1995: ¥14,600,000 (Direct Cost: ¥14,600,000)
Fiscal Year 1994: ¥14,000,000 (Direct Cost: ¥14,000,000)
Fiscal Year 1993: ¥13,900,000 (Direct Cost: ¥13,900,000)
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Keywords | Geothermal Energy / Fractals / Subsurface Crack / Hydraulic Stimulation / Thermal Design / Multi-crack / Fracture Mechanics / Water-Rock Interaction / 地熱開発 / 地下き裂モデル / 熱抽出 / 岩石熱水相互作用 / 力学的応答 / 岩石-熱水相互作用 |
Research Abstract |
The objective of the present research program is to develop a numerical model for predicting long-term performance of thermal extraction from geothermal reservoirs. The research program consists of the following major subjects, and three research group (RG) are formed to examine each research subject : (1) Characterization of subsurface natural fracture networks based on fractal geometry (RG : A01) (2) Modeling of mechanical responses of fracture-type rock mass stimulated by hydraulic fracturing (RG : A02) (3) Characterization of water-rock interaction (RG : A03) The following results are obtained from the RG activities. Firstly, a fractals-based method has been worked out which allows the generation of a 3D fracture network using a well logging data obtained from the reservoir considered. Then, numerical models have been developed to analyze the mechanical behavior of the geothermal reservoir during hydraulic stimulation process, steady state fluid flow at circulation stage, and heat extr
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action through the fractured rock mass, based on the generated fractal fracture network and the inputs measurable from field data. The numerical model of hydraulic stimulation allows to take into account the shear displacements of the stimulated fracture as well as the openings at a given treatment pressure, and to calculate the amount of fluid needed to stimulate a given volume of rock. The numerical models allows to predict the shape of the stimulated region, the recovery rate of circulating fluid, and then the long-term temperature variation of produced fluid. Finally, we have established a computer simulation model for predicting long-term performance of thermal extraction from a fracture network type geothermal reservoir, on the basis of the above-mentioned fundamental results. The model has been applied to examine the effect of geothermal reservoir size on the thermal output. International co-operative joint research programs have also been conducted to support the present study. Three international symposia have been held to disseminate our research results in addition to annual research group meeting. Furthermore, we have issued ten news-letters to facilitate the information change within the research groups. Less
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