基于Gassmann方程流体替换的影响因素分析

Analysis of factors influencing fluid substitution based on Gassmann equation

岩石物理是将地震数据与油藏特性和储层参数联系到一起的理论基础.流体替换是岩石物理分析中的重要手段,而Gassmann方程是流体替换中最重要的理论基础之一.因此,研究Gassmann方程中的各个参数对结果的影响是十分必要的.本文分析了Gassmann方程的理论基础,并探讨了方程中岩石参数和流体参数的求取方法,重点分析了方程中的各参数误差对结果的影响,认为岩石密度和剪切模量对流体替换后的纵横波速度影响较大.研究结果为利用地震资料和测井资料进行流体替换提供了指导和参考作用.

Rock physics is the theoretical basis of the connection between the seismic data and the reservoir characteristic parameters.Fluid substitution is an important method of Petrophysical analysis,and Gassmann equation is one of the most important theoretical basis for the fluid substitution.Therefore,it is necessary to discuss the effects of different parameters on the results of the Gassmann equation.In this paper,the theoretical basis of the Gassmann equation is analyzed and the calculation method for the rock and fluid parameters is discussed.The efforts are focused on the analysis of the influences caused by the errors of parameters.It is shown in the results that the rock density and shear modulus are of the top influences for the velocity estimation after the fluid substitution. The results provide the guidance and references for the fluid substitution based on the seismic and log data.