基于贝叶斯理论的粘弹介质AVF衰减反演方法  

AVF attenuation inversion method for viscoelastic media based on bayesian theory

作　　者：周单 ZHOU Shan(Sinopec Geophysical Research Institute Co.,Ltd,Nanjing,210003,China)

机构地区：[1]中石化石油物探技术研究院有限公司,南京210003

出　　处：《物探化探计算技术》2024年第2期127-136,共10页Computing Techniques For Geophysical and Geochemical Exploration

基　　金：国家自然科学基金企业创新发展联合基金(U19B6003)。

摘　　要：笔者通过引入贝叶斯反演框架,将AVF分析融入反演机制之中,以地质、测井、地震解释资料作为先验信息,构建从粘弹性参数到地震数据的似然函数,以后验概率的形式给出反演结果,从而建立了一种适合地下地质模型与参数估计的粘弹性介质反演方法。首先通过简化Aki-Richards公式,并引入粘弹性介质中两个新的衰减参数Q_(p)和Q_(s),推导出粘弹性介质AVF的近似表达式;然后从粘弹性介质下线性化的AVF公式出发,基于贝叶斯反演的框架,将初始模型中的先验信息以及测井曲线的互相关信息加入到数据反演中来,得到要求解的后验概率模型。通过理论模型数值实验和实际工区应用表明,该方法可以对地下介质的纵横波衰减进行直接反演,衰减异常能够指示可能的含气储层,从而为储层预测提供了更多的信息,减低了预测的风险。In this paper,a viscoelastic medium inversion method suitable for underground geological model and parameter estimation is established by introducing Bayesian inversion framework,integrating AVF analysis into the inversion mechanism,using geological logging seismic interpretation data as prior information,constructing the likelihood function from viscoelastic parameters to seismic data,and giving the inversion results in the form of a posterior probability Firstly,by simplifying Aki-Richards formula and introducing two new attenuation parameters Q_(p)and Q_(s)in viscoelastic medium,the approximate expression of AVF in viscoelastic medium is derived.Then,starting from the linearized AVF formula in a viscoelastic medium,based on the framework of Bayesian inversion,the prior information in the initial model and the cross-correlation information of the logging curve are added to the data inversion.The posterior probability model is obtained through numerical experiments of theoretical models and practical applications,which show that this method can directly invert the attenuation of vertical and horizontal waves of underground media.The attenuation anomalies can indicate the possible gas-bearing reservoirs,thus providing more information for reservoir prediction and reducing the risk of prediction.

关 键 词：贝叶斯 粘弹介质 AVF反演 品质因子Q 

分 类 号：P631.4[天文地球—地质矿产勘探]