American Rock Mechanics Association
June 23, 2013

Solution to the anisotropic stress equation evolved from Eaton [6] requires knowledge of horizontal and vertical elastic properties. 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.

Authors: Munir Aldin, Rich Rosen, Meghana PaiAngle, and Robert Patterson