1986 Fiscal Year Final Research Report Summary
Study on the Effective Utilization of Exploration Techniques for the Estimation of Geothermal Resources
| Project/Area Number |
60460186
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| Research Category |
Grant-in-Aid for General Scientific Research (B)
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| Allocation Type | Single-year Grants |
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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 |
YOKOYAMA Hidekichi Tohoku University, Professor, 工学部, 教授 (70005198)
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| Co-Investigator(Kenkyū-buntansha) |
SATO Motoyuki Tohoku University, Research Associate, 工学部, 助手 (40178778)
ABE Mamoru Tohoku University, Research Associate, 工学部, 助手 (50005310)
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| Project Period (FY) |
1985 – 1986
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| Keywords | Resistivity / High temperature and pressure / Automatic analysis |
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| Research Abstract |
To interpret electrical surveys in terms of resistivity layer boundaries and formation temperatures, a good knowledge of the relationship between rock resistivity and temperature is essential. Experimental data on the electrical resistivity of rocks at various temperature and pressures close to the conditions actually encountered in the earth's crust are scarcely documented. The temperature range of practical interest for the exploration of geothermal reservoirs lies between 200゜C and 300゜C, and concerns host rocks having their pore space saturated with hydrothermal solutions. We have devised an experimental procedure for measuring the temperature dependence of rock resistivity capable of reproducing reasonably in-situ conditions. Next, a computer program intended for automatic analysis of horizontally multi-layered structures was improved to adapt to the inclined two-layer case with an arbitrary dip angle of the interface. This computation procedure was further developed for a horizontally multi-layered model with an inclined basement, and applied to the data obtained from field measurements.
Finally, the potential field based on induced current sources due to primary flow is calculated with the FEM method. The result of D survey line at the Onikobe geothermal area can be interpreted by the use of the distribution of the induced current sources caused by the primary flow. On the other hand, as the effect of s streaming potential may be included for B survey line, it is necessary that the effects of sources added newly near the surface between each fault are considered.
The results mentioned above show that the purposes of our studies may be fully accomplished.
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Research Products
(6 results)
