| Project/Area Number |
18560780
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| Research Category |
Grant-in-Aid for Scientific Research (C)
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| Allocation Type | Single-year Grants |
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| Section | 一般 |
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| Research Field |
Earth system and resources enginnering
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| Research Institution | Tohoku University |
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Principal Investigator |
MORIYA Hirokazu Tohoku University, Graduate School of Engineering, Tohoku University, Senior Assistant Professor (60261591)
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| Project Period (FY) |
2006 – 2007
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| Project Status |
Completed (Fiscal Year 2007)
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| Budget Amount *help |
¥3,950,000 (Direct Cost: ¥3,500,000、Indirect Cost: ¥450,000)
Fiscal Year 2007: ¥1,950,000 (Direct Cost: ¥1,500,000、Indirect Cost: ¥450,000)
Fiscal Year 2006: ¥2,000,000 (Direct Cost: ¥2,000,000)
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| Keywords | AE / Microearthquake / Geothermal / Fracture / Permeability / Multiplet / Fault / Shear slip |
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| Research Abstract |
I have carried out the research for the development of the method to evaluate the permeability of sunsurface fracture. I have taken form the method for the evaluation of permeability. On the basis of the results which obtained through the research before, I have shown that it is possible to estimate the direction of fluid flow and the growing process of permeable fracture system by the time lapse distribution of source location determined by the multiplet-clustering analysis. I have also revealed that the pressure gradient as well as the critical pore-pressure of fractures during the hydraulic stimulation of geothermal reservoir can be estimated by the integration of the tectonic stress field and the fracture orientation and the time lapse distribution of AE source location, where I used the induced AE data at the Soultz HDR field in France. I have also shown that it is difficult to estimate the velocity of pressure propagation because the number of events is insufficient number and the source does not distribute all over the reservoir. On the other hand, I have demonstrated that the degree of fluid flow in the reservoir can be evaluated by refining the increasing rate of seismic moment release and the increasing rate of source area. The dynamic behavior of subsurface fracture was also examined, where the relationship between the frequency band for identifying similar microearthquakes (multiplet) and the structures delineated by the source location of multiplet.
As the results, I have developed the procedure to evaluate the fracture permeability in the geothermal reservoir on the basis of the precisely determined source location by the multiplet-clustering analysis, and also revealed the restriction on the evaluation.
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