Scientists drilling oil at reservoirs, especially at the Niger Delta basin, have been facing the fundamental issue of 4D seismic interpretations in which velocity changes due to stress produced ambiguity in the separation of fluid effects and geomechanical deformation. To solve this problem, the key step is to create a combined workflow that would quantitatively predict anisotropic velocity variations to improve seismic attribute interpretation. Dynamic stress and strain are modeled by a coupled geomechanical-fluid flow simulation and fed into a microstructural rock physics model to compute seismic velocity perturbations. The experimental results at the Pearl field, Niger Delta, have shown that such integration can predict measured 4D time shifts and amplitude differences well and substantially mitigate interpretation risks and offer a simple approach to monitor pore pressure, compaction, and fluid fronts.

Keywords: Anisotropic Velocity, Reservoir Geomechanics, Seismic Attribute, Seismic Interpretation and 4D Seismic.