Integration of seismic methods and 3D basin modeling approach for improved predrill pore pressure prediction: an example from Malay Basin, Malaysia

In the Malay Basin, vast area under the top of overpressure remains unexplored due to high overpressure in the deeper strata. This necessitates the careful estimation of predrill pore pressure for well planning, safe drilling, and migration modeling for prospect evaluation. 3D predrill pore pressure prediction is carried out using 3D pre-stack depth-migrated seismic interval velocity and 3D basin modeling technique. Eaton method is used for 3D pore pressure prediction using seismic interval velocity. Eaton method with its default parameters did not give good prediction results. Therefore, its exponent was calibrated with measured pressure data obtained from repeated formation tester. Hence, modified Eaton exponent is used which gave best match between predicted and measured pressure data. 3D basin modeling is carried out to test various hypotheses and reconstruct the overpressure evolution in the study area. Basin modeling pressure prediction results have shown that it can successfully predict the pore pressure when appropriate input parameters such as porosity-permeability history is considered. This study aims to evaluate the results of pore pressure prediction obtained from both the techniques and to compare the predicted pressure with measured pressure data. The findings of this study have shown that although both basin modeling and seismic velocity can successfully replicate the measured pressure profiles, in some faults blocks, they still have minimal prediction error because of the limitation of each method. Hence, integration of both methods is useful to further minimize the prediction error, improve the accuracy of predrill pore pressure prediction, and reduce the drilling hazards in the study area.