泥岩基质弹性参数对Xu-White模型横波速度估算的影响

Influence of clay elastic parameters on S-wave velocity estimation based on Xu-White model

Xu-White模型被广泛用于砂、泥岩横波速度预测。通常在利用该方法进行横波速度预测时,往往假定各深度点泥岩基质的纵、横波时差及密度三个岩石参数为常数,这会引起岩石基质弹性模量估算不准确,进而影响横波速度计算精度。数值分析表明,调整泥质中黏土矿物类型及混合比例可引起横波速度的变化。实例分析表明,考虑变化的泥质弹性参数,利用反演对Xu-White模型的输入参数进行误差校正,可提高横波速度的预测精度。

Xu-White model has been widely used in claysand S-wave velocity prediction.When using this method to predict S-wave velocity,people usually assumes three clay parameters with fixed value,Pwave transmit time,S-wave transmit time,and density,which may lead to the inaccuracy estimation of matrix modulus,indirectly affect the precision of Swave velocity.Our numerical simulation shows that the clay minerals types and their proportion can more or less affect the S-wave velocity.Case studies show that based on changed clay parameters,the error correction of input parameters for XuWhite model by inversion,can improve the accuracy of S-wave velocity prediction.