Abstract
The hydraulic fracturing technique as a potential method for determination of in-situ stresses has the advantage in contrast to the stress relief techniques in that it is not in need of the elastic modulus of rock. However, the level of confidence in the measured maximum principal stress is lower than in the minimum principal stress. In many instances, the maximum principal stress, generally the more important, is not directly measured.
In order to seek the possibility to measure the maximum principal stress directly from the shut-in pressure data by making a (pair of) artificial longitudinal slot (s) along the minimum principal stress direction, the authors carried out numerical analyses by boundary element method and laboratory tests using cubic specimens of mortar, which has a borehole with slot. This paper describes the results obtained from these experimental and numerical works.
