Pore Pressure Prediction Based on Seismic Data for Exploration Well Before Drilling

Abstract

Pore pressure prediction before drilling is significant on ensuring drilling safety, reasonable drilling mud density, and designing well profile. It can also reduce the drilling cost and protect the hydrocarbon reservoir. With the increasing quality of seismic data and widely application of new methods, high-resolution seismic was used to reduce the uncertainty of the pore pressure prediction in this paper. Through the past years study, workflows were developed which use the high resolution seismic for pore pressure prediction. The workflows mainly include three steps. The first step is the mechanisms analysis for pore pressure prediction. The geological genesis is the key to pore pressure prediction. Base on the geological genesis, Fillippone method was optimization and adjustment, such as seismic velocity analysis and variation rate of seismic velocity estimation based on geological consistency. After the method optimization, the overburden pressure and pore pressure will be estimated by the seismic data, integrated with regional geological data and shallow well logging data. A postmortem from southwest of Iraq is presented showing a successful well that were better predicted before the well were drilled. The prediction result accuracy error is less than 5% compared with the measured data which is tested by well drilling and this indicates that the method can greatly improve the accuracy of pressure prediction before drilling. With the increasing quality of seismic data, the high-resolution seismic data will play more and more important role in pore pressure prediction. The method integrated seismic, geological and well logging data for formation pressure prediction will reduce the uncertainty greatly.