Pore Pressure Prediction Using Acoustic Impedance

Abstract

Summary Currently, pore pressure prediction based on seismic data is obtained by calibrating through a correction factor, between processing velocity and sonic logs. However, processing velocity data does not represent subsurface lithology, so that calibrated velocity models produce approximate and low-resolution pore pressure volumes. Motivated by this, we present a methodology to transform acoustic impedance data to pore and fracture pressure gradient, incorporating resistance information to propagation of seismic energy into siliciclastic formations, obtaining models with higher vertical and lateral resolution, that are geologically consistent. We apply this proposed methodology to open seismic data from the Browse basin, in Western Australia, estimating pore and fracture pressure volumes in an area of 120 km2. The validation of results arises from comparing predicted against calculated data in post-mortem of the Poseidon-1 and Boreas-1 wells. We intend to use this methodology as a complementary process to conventional pore pressure prediction based on effective stress, using acoustic impedance data with the objective to reduce uncertainty in future pore pressure prediction projects for the Mexican industry.