LABORATORY DETERMINATION OF THE IN-SITU STRESS TENSOR

SYNOPSIS Core specimens drilled and obtained from deep, soft formations usually exhibit a large amount of oriented cracks. These microcracks, if not preexisting in the formation, are attributed to stress relaxation during coring and can be used as a fingerprint to obtain indications on the in-situ state of stress. This paper proposes two techniques to obtain information on the in-situ stress tensor. A field study is presented which provides a good validation of the methods.