A new method is proposed for in situ tectonic stress measurement by hydraulic fracturing. The method employs an artificial notch created at the wellbore surface. The 3-D stresses are determined by using formulae derived from studies on crack initiation, crack curving and the stress distribution near the artificial notch. Hence, the method is applicable to a case in which the orientation of principal axes of the tectonic stress are totally unknown; this is generally the case of most geothermal fields. The method has been applied to the Higashi Hachimantai geothermal model field of HDR, Tohoku University. The application results show that the least compressive stress is in neither the vertical direction nor the horizontal plane, contrary to the prediction of the conventional method.
|Number of pages||6|
|Journal||International Journal of Rock Mechanics and Mining Sciences and|
|Publication status||Published - 1989 Jul|
ASJC Scopus subject areas
- Geotechnical Engineering and Engineering Geology