Linear numerical calculation method for obtaining critical point,pore fluid,and framework parameters of gas-bearing media  

含气介质临界点、流体和骨架弹性参数的线性数值计算方法(英文)

作　　者：牛滨华[1] 孙春岩[1] 闫国英[1] 杨维[1] 刘畅[1] 

机构地区：[1]中国地质大学(北京),中国北京100083

出　　处：《Applied Geophysics》2009年第4期319-326,393,共9页应用地球物理（英文版）

基　　金：supported by the National Natural Science Foundation of China (Grant No.40874052);the Key Laboratory of Geo-detection (China University of Geosciences,Beijing),Ministry of Education

摘　　要：Up to now, the primary method for studying critical porosity and porous media are experimental measurements and data analysis. There are few references on how to numerically calculate porosity at the critical point, pore fluid-related parameters, or framework-related parameters. So in this article, we provide a method for calculating these elastic parameters and use this method to analyze gas-bearing samples. We first derive three linear equations for numerical calculations. They are the equation of density p versus porosity Ф, density times the square of compressional wave velocity p Vp^2 versus porosity, and density times the square of shear wave velocity pVs^2 versus porosity. Here porosity is viewed as an independent variable and the other parameters are dependent variables. We elaborate on the calculation steps and provide some notes. Then we use our method to analyze gas-bearing sandstone samples. In the calculations, density and P- and S-velocities are input data and we calculate eleven relative parameters for porous fluid, framework, and critical point. In the end, by comparing our results with experiment measurements, we prove the viability of the method.临界孔隙度及其孔隙介质的研究均为测试分析的实验方法,如何运用数值计算方法求取孔隙流体介质临界点、流体和骨架的弹性参数是备受关注的课题。本文提出了求取临界点、流体和骨架弹性参数的数值计算公式及方法,并结合含气样品测试数据实现了这种数值计算。首先,基于孔隙度Φ为自变量,而密度ρ,密度与横波速度平方的乘积ρVs2和密度与纵波速度平方的乘积ρVp2均为函数的三个线性方程,从每个线性方程中的两个系数的有机组合得到求取有关弹性参的线性数值计算公式。然后,详细阐述了数值计算的步骤和方法以及需要注意的问题,把室内含气砂岩数的线性数值计算公式。然后,详细阐述数值计算的步骤和方法以及需要注意的问题,把室内含气砂岩样品测试的整体介质密度、纵波速度和横波速度作为数值计算的输入数据,求取了临界点和流体及骨架共计11个弹性参数的具体数值。通过数学方法的计算数据与实验方法的测试数据的比较分析,表明了本文数值计算公式的正确性和实现方法的有效性。本文提出的求取含气介质临界点、流体和骨架弹性参数的"数值计算公式及方法"含义清晰且形式简洁,为孔隙流体介质的数值计算分析和流体属性研究提供了可能的新方法。

关 键 词：linear equation numerical calculation gas-bearing media critical point pore fluid and framework elastic parameters 

分 类 号：O35[理学—流体力学]