Calculations of rock matrix modulus based on a linear regression relation  

求取岩石基质体积模量的线形拟合方法(英文)

作　　者：贺锡雷[1] 贺振华[1] 汪瑞良 王绪本[1] 蒋炼[1] 

机构地区：[1]油气藏地质及开发工程国家重点实验室成都理工大学,610059 [2]中海石油(中国)有限公司深圳分公司,518067

出　　处：《Applied Geophysics》2011年第3期155-162,239,共9页应用地球物理（英文版）

基　　金：supported by the National Nature Science Foundation of China (Grant Noss 40739907 and 40774064);National Science and Technology Major Project (Grant No. 2008ZX05025-003)

摘　　要：The rock matrix bulk modulus or its inverse, the compressive coefficient, is an important input parameter for fluid substitution by the Biot-Gassmann equation in reservoir prediction. However, it is not easy to accurately estimate the bulk modulus by using conventional methods. In this paper, we present a new linear regression equation for calculating the parameter. In order to get this equation, we first derive a simplified Gassmann equation by using a reasonable assumption in which the compressive coefficient of the saturated pore fluid is much greater than the rock matrix, and, second, we use the Eshelby- Walsh relation to replace the equivalent modulus of a dry rock in the Gassmann equation. Results from the rock physics analysis of rock sample from a carbonate area show that rock matrix compressive coefficients calculated with water-saturated and dry rock samples using the linear regression method are very close （their error is less than 1%）. This means the new method is accurate and reliable.岩石基质的体积模量或其倒数--压缩系数,在进行油气预测的流体替换和孔隙度反演时,是重要的输入参数,但是利用现有方法很难准确求得。文中提出了一种求取该参数的线形拟合方法,该方法通过对Gassmann方程的合理简化并引入Eshelby-Walsh干燥岩石椭球包体近似公式,获得了计算岩石基质压缩系数的拟合公式,可方便地利用公式计算该参数。实际碳酸盐岩岩样的岩石物理测试分析显示:利用饱和岩样和干燥岩样测得的基质压缩系数的差异小于1%,说明所求参数是正确的,可靠的。

关 键 词：Bulk modulus rock matrix fluid substitution rock physics linear regression 

分 类 号：P618.13[天文地球—矿床学]