Static and Dynamic Characterization of a Deep Overburden Shale

Abstract

Since shales are the far most abundant overburden formation, understanding the geomechanical and rock physics behavior of shales is essential. We discuss a particular deep overburden shale in light of a thorough static and dynamic multi-directional data acquisition, as a basis for complete static and dynamic characterization assuming transverse isotropy. The stress-and strain-path dependence of the principal P- and S-wave velocities are also analyzed. These quantities are of great interest for interpretation of seismic or sonic-log overburden signatures upon reservoir depletion (or injection), as geomechanical simulations show significant variations of stress and strain changes throughout the overburden.