Effects of isotropic and anisotropic stresses on elastic properties of shales

Abstract

Understanding seismic anisotropy in shales is important for quantitative interpretation of seismic data, 4D monitoring and pore pressure prediction. Along with intrinsic anisotropy caused by preferred mineral orientation that is common in shales, anisotropic stress is an important factor that affects shale elastic response. The effect of stress on elastic properties of shales is also important for understanding of depositional trends especially at the upper 2000-3000 meters where the compaction is mostly mechanical. Despite the importance of the effects of isotropic and especially anisotropic stress on elastic properties of shales, little work has been done on theoretical understanding and predicting such properties.