Effective Experimental Methods to Validate Anisotropic Geomechanical Model for Shale Gas Reservoir Evaluation: Methods & Case Study from Middle East

Solution to the anisotropic stress equation evolved from extended Eaton requires knowledge of horizontal and vertical elastic properties (Equation 1). Its application to derive a general well log based acoustic model is facilitated using laboratory acoustic measurements at horizontal, vertical, and 45 degree orientation. However, obtaining 45 degree samples are very difficult due to the fragile nature of laminated, textured, and unconventional shales. Instead of using such samples, an acoustic transducer has been developed to measure velocity at 45 degrees; thus only needing simpler to cut vertical and horizontal samples. For the unconventional shales considered, the resulting model is robust and appears to fit a wide range of well data from different formations, fields and basins. The presentation also includes anisotropic Geomechanical characterization examples including some from Middle Eastern shale play evaluation.