地层孔隙压力预测新方法

New approach for pore pressure prediction

在分析地层孔隙压力预测传统方法局限性的基础上,提出了一种基于有效应力定理和声波速度模型的地层孔隙压力预测方法。由相关测井资料计算泥质含量、孔隙度和声波速度,通过支撑向量回归机计算垂直有效应力,密度测井资料计算上覆岩层压力,最后根据有效应力定理计算地层孔隙压力。实例分析表明,该方法用于预测砂泥岩及欠压实成因的异常地层压力是可行的。与传统方法相比,该方法不需要建立正常压实趋势线,有较好的适应性和预测精度。

By analyzing the limitations of the traditional pore pressure prediction methods, a new pore pressure prediction approach based on the effective stress theorem and the acoustic velocity model is proposed. It first calculates clay content, porosity, and acoustic velocity with relevant log data, and then calculates vertical effective stress by using Support Vector Machines for Regression and the overburden pressure with density log data, and finally calculate formation pore pressure by the effective pressure theorem. Practical application of the approach shows that it is feasible in prediction of abnormal formation pressure of sandstone and shale caused by undercompaction. Compared with traditional pore pressure prediction methods, the approach does not require establishing normal compaction trend line and has better adaptability and higher accuracy of predictions.