Detection of Flow-pathway Structure based on Pore Pressure Distribution Estimated from Micro-seismic Events

• ITO Takatoshi

  Institute of Fluid Science, Tohoku University

• OSADA Kazuyoshi

  Institute of Fluid Science, Tohoku University Geothermal Engineering Co. Ltd.

• HAYASHI Kazuo

  Institute of Fluid Science, Tohoku University

• BARIA Roy

  EEIG “Heat Mining”, Route de Soultz

Bibliographic Information

Other Title

• 微小地震情報から求めた間隙水圧分布に基づく貯留層内の流路構造評価
• ビショウ ジシン ジョウホウ カラ モトメタ カンゲキ スイアツ ブンプ ニ モトズク チョリュウソウナイ ノ リュウロ コウゾウ ヒョウカ

Abstract

In the hydraulic stimulation, a number of micro-seismic events are commonly observed. It is believed that injected fluid flows through subsurface pre-existing fractures, and the fluid flow raises pore-pressure in those fractures, and finally the raised pore-pressure triggers micro-seismic events. In the previous work of Osada et al. (2005), we have considered carefully such a scenario and come up with a method to estimate pore-pressure distribution in a rock formation by analyzing the observed data of micro-seismic events. On the other hand, pore pressure distribution along flow-pathways should change according to the location of flow-pathways and the distribution of hydraulic conductivity along them. Therefore, it could be possible to estimate flow-pathway structure as it gives a good explanation of the pore pressure distribution. Based on this idea, in the present work we propose a new method to estimate the flow-pathway structure. We assume an appropriate model of flow-pathway structure and optimize it as the pore pressure distribution estimated numerically by the model agrees well with the pore pressure distribution estimated from micro-seismic events by the method proposed in the previous work. Then we accept the most optimized model as the answer to represent the actual flow-pathway structure.We demonstrated how we can optimize the model of flow-pathway structure according to synthetic pore pressure distributions in 1D and 2D cases. Finally we applied this method to Soultz field in France and estimated the subsurface flow-pathway structure. The results were in good agreement with the flow logs carried out in the injection well.

Journal

• Journal of the Geothermal Research Society of Japan

  Journal of the Geothermal Research Society of Japan 30 (1), 49-60, 2008

  THE GEOTHERMAL RESEARCH SOCIETY OF JAPAN

Keywords

• Reservoir
• Flow-pathway
• Pore pressure
• Hydraulic Stimulation
• Microseismic Event

Details

• CRID: 1390282681103274112
• NII Article ID: 130003624394
• NII Article ID: 10021161620
• NII Book ID: AN00333995
• DOI: 10.11367/grsj1979.30.49
• ISSN: 18835775
• ISSN: 03886735
• NDL BIB ID: 9383335
• Web Site: https://ndlsearch.ndl.go.jp/books/R000000004-I9383335
• Data Source:
  • JaLC
  • NDL
  • CiNii Articles
• Abstract License Flag: Disallowed