3D Pore Pressure Prediction Using Seismic Data in an Oil Field in SW Iran

Abstract

The pore pressure prediction method based on seismic velocity field is a common method for constructing a 3-D pore pressure cube. In this study, the resolution of stacking velocity was improved using sonic logs and a geostatistical calibration method. In this calibration procedure, the differences between velocity derived from sonic logs and stacking velocity were calculated and, then, the calibration parameters were obtained. These parameters were interpolated in the velocity grids. Effective pressures were calculated using the measured pore pressures and the calculated overburden pressures at well locations. The coefficients of Bowers equation were calculated using well data. Using the Bowers equation the calibrated stacking velocity cube was converted to the effective pressure cube. The pore pressure cube was constructed by computing the differences between the overburden pressure cube and the effective pressure cube. Finally the predicted pore pressure cube was calibrated with regard to the measured pore pressures at well locations. In the area of study, the stacking velocity was improved and, then, the pore pressure cube was made accordingly. The predicted pressures show good agreement with regard to the measured pressures at well locations.