| Project/Area Number |
25870600
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| Research Category |
Grant-in-Aid for Young Scientists (B)
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| Allocation Type | Multi-year Fund |
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| Research Field |
Solid earth and planetary physics
Earth system and resources engineering
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| Research Institution | Yokohama City University |
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Principal Investigator |
KIM AHYI 横浜市立大学, 総合科学部, 准教授 (00633851)
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| Project Period (FY) |
2013-04-01 – 2016-03-31
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| Project Status |
Completed (Fiscal Year 2015)
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| Budget Amount *help |
¥2,340,000 (Direct Cost: ¥1,800,000、Indirect Cost: ¥540,000)
Fiscal Year 2015: ¥910,000 (Direct Cost: ¥700,000、Indirect Cost: ¥210,000)
Fiscal Year 2014: ¥650,000 (Direct Cost: ¥500,000、Indirect Cost: ¥150,000)
Fiscal Year 2013: ¥780,000 (Direct Cost: ¥600,000、Indirect Cost: ¥180,000)
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| Keywords | 地震 / 微小地震 / みかけ応力 / 応力降下量 / 発震機構 / 誘発地震 / 水圧破砕 / シェールガス / 震源メカニズム / テンサイルクラック / 見かけ応力 / 体積変化 / 剪断破壊 / 地震のメカニズム / 流体注入 |
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| Outline of Final Research Achievements |
Understanding the source characteristics of hydraulic-fracturing-induced microearthquakes is expected to provide better understanding of both the fracturing process and the influence of pre-existing structures on the distribution of events. However, details of the source characteristics of microearthquakes remain largely unknown. To address this issue, we estimated the apparent stress of the microearthquakes observed during the hydraulic fracturing in the Carthage Cotton Valley Gas Field. As a result, lower apparent stress was observed for the events striking subparallel to the maximum horizontal compressional stress axis. This implies the mechanism of these events could be different from that of events optimally oriented for failure.
In addition, we developed more direct method to retrieve non-double couple component from hydraulic fracturing induced microearthquakes constraining the mechanism to be shear slip, tensile displacement, or combination of these mechanisms.
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