基于等效弹性模量反演的横波速度预测方法

A method for S-wave velocity estimation based on equivalent elastic modulus inversion

为了有效地解决常规的基于Xu-White模型的横波速度预测方法中基质矿物的弹性模量难以准确设定的问题,本文提出了一种新的基于等效弹性模量反演的横波速度预测方法。该方法首先设定单个测井深度点的干岩石的泊松比和基质矿物的等效体积模量的取值范围和初始值,然后采用两种不同的流体项计算方法从两个不同的角度对相同的流体项进行反演求解,反演出最优的干岩石的泊松比、基质矿物的等效体积模量和等效剪切模量,再采用基于简化的Xu-White模型估算横波速度。实例计算结果表明,文中方法以基质矿物的等效弹性模量为研究对象,通过减小目标参数的个数,有效地提高了横波速度估算的精度和可靠性。

To deal with the difficulty of calculation of matrix mineral elastic modulus in regular S-wave velocity estimation methods based on Xu-White model,the paper proposes a novel method for S-wave velocity estimation based on equivalent elastic modulus inversion.Firstly,the method calculates the range and initial value of Poisson's ratio of dry core sample and equivalent bulk modulus of matrix mineral.Then,it calculates the fluid section by two different methods based on inversion method,and obtains the Poisson's ratio of dry core sample and equivalent elastic modulus of matrix mineral.Finally,this method uses the approximative Xu-White model to estimate the S-wave velocity.Through study of the equivalent elastic modulus of matrix mineral,the method effectively improves the accuracy and reliability of S-wave velocity estimation by reducing the number of target parameters.