Empirical Procedure Investigation for Sandstone Anisotropy Evaluation: Part II

ABSTRACT: A laboratory methodology of an anisotropy evaluation for fine grain sandstone is reported. The methodology involved four types of tests: (i) point load strength (OPLS) and (ii) compliant and non-compliant drilling as two primary tests, and (iii) ultrasonic wave velocity (OUSWV) measurement and (iv) unconfined (uniaxial) compressive strength (UCS) as supporting tests. Each test was conducted on samples produced from the same natural sandstone block in three orientations: vertical, diagonal, and horizontal. The primary tests were conducted for sandstone characterization determined by OUSWV using published anisotropy indices, and correlated with UCS. The tests showed sandstone isotropy, and are part of an ongoing study to develop a rock anisotropy characterization procedure.