基于ADCIGS预测地层孔隙压力的方法研究  

Predicting the formation pore pressure based on ADCIGS

作　　者：张冰[1] 徐嘉亮 ZHANG Bing;XU JiaLiang(School of Geosciences,Northeast Petroleum University,Daqing 163318,China)

机构地区：[1]东北石油大学地球科学学院

出　　处：《地球物理学报》2020年第1期313-319,共7页Chinese Journal of Geophysics

基　　金：东北石油大学培育项目“三维高精度异常高压预测方法研究”(15071120531)资助

摘　　要：工业界计算孔隙压力系数普遍应用的Eaton和Fillippone方法都需要构建能够准确表征低速层的层速度模型,层速度模型精度及效率成为制约孔隙压力预测的关键参数,但目前工业界层速度建模的精度及效率很难满足孔隙压力预测的要求.本文由正常压实情况下的背景速度场出发,基于时距曲线公式及角道集抽取公式,创新推导了以角度域共成像点道集(ADCIGS)剩余曲率为自变量的孔隙压力系数计算公式,该公式完全由去噪后的地震数据进行驱动,不需要构建层速度模型,该方法大幅提高了计算孔隙压力系数的效率.由模型测试及实际数据应用证明,利用本文提出方法进行孔隙压力预测是有效可行的,该方法可以有效提高预测孔隙压力精度,还可以有效提高预测孔隙压力效率.The pore pressure is closely related to the formation and migration of oil and gas.In addition,abnormal pore pressure is directly related to the safety of drilling.Therefore,accurate prediction of pore pressure coefficients is critical.The abnormal pore pressure formed by mudstone under low compaction is characterized by low velocity and low resistance.The Eaton method and Fillippone method,which are widely used in industry,need to construct a layer velocity model which can accurately describe low velocity,and many of the subsequent methods are also constantly around the layer velocity.Therefore,the accuracy of the layer velocity model becomes the key parameter to predict the pore pressure.However,the accuracy of layer velocity modeling method can not meet the demand of pore pressure prediction at present.This paper starts with the background velocity field under normal compaction,then derives the relation between the residual curvature of the angle set as the independent variable and the pore pressure coefficient as the objective function.Tests on a model and actual data show that this formula is effective and feasible to predict pore pressure.The method can not only effectively improve the calculation accuracy of the pore pressure,but also effectively enhance the efficiency of the calculation.

关 键 词：孔隙压力 泥岩欠压实 层速度场 角度域共成像点道集(ADCIGS) 压力系数 

分 类 号：P631[天文地球—地质矿产勘探]