Fracture characterization was attempted by the use of crack waves which were detected in the Higashi-Hachimantai geothermal model field, Japan. For the characterization, field data observed during drilling a well near the target crack were used. Characterization method was constructed based on the dynamics of a penny shaped crack filled with fluid. By the use of this characterization method, it is possible to estimate crack aperture, radius and interfacial stiffness due to partial contact between upper and lower crack surfaces. These factors are estimated by comparing peak frequencies detected from field data with eigen frequencies suggested by the crack model. The magnitude of the factors is dependent on reservoir pressure or wellhead pressure of one of the observatory wells. For example, crack aperture is around 0.3mm in the case that the wellhead pressure is lower than 2MPa and aperture is around 0.5mm in the case that the wellhead pressure is higher than 2MPa.
|ジャーナル||Transactions - Geothermal Resources Council|
|出版物ステータス||Published - 2003 12 1|
|イベント||International Collaboration for Geothermal Energy in the Americas - Geothermal Resources Counsil: 2003 Annual Meeting - Morelia, Michoacan, Mexico|
継続期間: 2003 10 12 → 2003 10 15
ASJC Scopus subject areas
- Renewable Energy, Sustainability and the Environment
- Energy Engineering and Power Technology