An Integrated Application of Reducing Uncertainties for 3D Pore Pressure Prediction: A Case Study

Abstract

Abstract Pore pressure is an important geologic parameter in drilling operation, once it influences the definition of mud weight, casing design, drilling cost evaluation, etc. Inaccurate estimates of pore pressure can lead to high costs and unsafe conditions. Basically, the current prediction methods of pore pressure are based on one-dimensional, and can not provide horizontal and the spatial distribution of formation pressure information. While the existing three-dimensional (3D) pore pressure prediction method is not mature enough, and prediction accuracy is not high. This paper presents an integrated application of reducing uncertainties in order to improve the accuracy of 3D pore pressure prediction and also to give a case study. Firstly, we transform the seismic interval velocities inverted from a 3D calibrated seismic migration volume to pore pressure with an initial pore pressure prediction model, this prediction results clearly have a large range and low accuracy. Next, used seismic data in conjunction with well logging data, mud weight and measured pressure, we can modify and improve model parameters of the initial prediction model. At last, the 3D pore pressure data volume is re-calculated by this new 3D prediction model. This integrated application has been used to improve the pressure prediction results of a petroleum province in the Western of China, and we can get a high precision 3D pore pressure data with this method through analysis and compare.