Well-constrained seismic estimation of pore pressure with uncertainty

Abstract

Summary A quantitative predrill prediction of formation pore pressure with uncertainty is needed for safe, cost effective drilling in overpressured areas. This paper describes the use of a 3D probabilistic Mechanical Earth Model (MEM) that combines well data with seismic velocities to predict pore pressure and uncertainty. Application is made to an overpressured area in the Gulf of Mexico. Parameters in the velocity-to-pore-pressure transform are estimated using seismic velocities plus density logs, pressure data, and well velocities obtained by inverting time-depth pairs from checkshots in the area. A prediction of pore pressure and uncertainty is made by sampling the region of parameter space consistent with available well data.