| Project/Area Number |
12450410
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| Research Category |
Grant-in-Aid for Scientific Research (B)
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| Allocation Type | Single-year Grants |
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| Section | 一般 |
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| Research Field |
資源開発工学
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| Research Institution | Tohoku University |
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Principal Investigator |
HASHIDA Toshiyuki Tohoku Univ. Graduate school of Eng. Prof., 大学院・工学研究科, 教授 (40180814)
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| Co-Investigator(Kenkyū-buntansha) |
NIIBORI Yuichi Tohoku Univ. Graduate school of Eng. Assistant Prof., 大学院・工学研究科, 助教授 (90180562)
MATSUKI Koji Tohoku Univ. Graduate school of Eng. Prof., 大学院・工学研究科, 教授 (10108475)
HAYASHI Kazuo Tohoku Univ. Institute of Fluid Science. Prof., 流体科学研究所, 教授 (30111256)
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| Project Period (FY) |
2000 – 2001
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| Project Status |
Completed (Fiscal Year 2001)
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| Budget Amount *help |
¥14,100,000 (Direct Cost: ¥14,100,000)
Fiscal Year 2001: ¥5,000,000 (Direct Cost: ¥5,000,000)
Fiscal Year 2000: ¥9,100,000 (Direct Cost: ¥9,100,000)
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| Keywords | Geothermal Energy / Hydraulic Stimulation / Thermal Extraction / Reservoir / Numerical Simulation Code / Fluid Flow Model / Fractals / Shear Dilation / せん段膨張角 |
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| Research Abstract |
An improved three-dimensional simulation model (FRACSIM-3D) for the fractured hot-dry-rock (HDR) geothermal reservoir is developed. It incorporates the mechanical rock-fluid interaction during hydraulic stimulation and quantitatively predicts the 3D reservoir growth behavior. In this model the pre-existing fractures are generated stochastically. The fractal size distribution of the penny-shaped fractures with random orientation is assumed. The fluid flow through the discrete fracture network is simulated by mapping the connectivity of the fractured rock to a regular cubic grid under condition of constant injection pressure. The fluid flow is approximated by the Darcy law equation. The fluid pressure from the injection well induces the growth of the fractures' apertures due to the fracture shear offset. Computation of the fracture dilation requires several iterations: solving the complete flow model simulating the fracture system anew each time and recalculating the shear displacement u
… More
sing the inner fracture pressure from the previous iteration. The numerical model is calibrated on the basis of the field data available for the Hijiori HDR reservoir. For instance, the series of numerical computations was carried for the different randomly seeded initial distributions of fractures and their apertures within the reservoir. The distribution, which leads to a good agreement of the numerically obtained and experimentally detected Hijiori reservoir's volume and growth direction, was chosen as an appropriate one for simulating the natural fractured media. The model was used for the assessment of the adequate stress regime of the Hijiory reservoir since the related field data obtained by the different experimental technique are not very reliable. The latest version of FRACSIM-3D incorporates the multi-borehole system of injection and production wells. This improvement of the model makes possible to analyze the effect of different borehole system arrangement on the reservoir productivity. A number of numerical experiments for the different geometrical boreholes configurations have been conducted. As a result, the optimal arrangements of the production and injection wells, which provide the relevant reservoir recovery rate with lesser amount of active boreholes, are proposed. Less
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