页岩油储层脆性指数贝叶斯叠前地震直接反演方法  

Bayesian direct inversion method for brittleness index of shale oil reservoir based on prestack seismic data

作　　者：张红杰 杨光[1] 吴昊 孙龙 刘智军[1] 高巍 乔传乡 曾勇坚 ZHANG Hongjie;YANG Guang;WU Hao;SUN Long;LIU Zhijun;GAO Wei;QIAO Chuanxiang;ZENG Yongjian(Institute of Geophysical Exploration,PetroChina Jilin Oilfield Company;The Exploration Department,PetroChina Jilin Oilfield Company;Beijing Precise Energy Technology Co.,Ltd)

机构地区：[1]中国石油吉林油田公司地球物理勘探研究院,吉林省松原市138001 [2]中国石油吉林油田公司勘探事业部 [3]北京普瑞斯安能源科技有限公司

出　　处：《海相油气地质》2025年第2期177-184,共8页Marine Origin Petroleum Geology

摘　　要：裂缝参数与脆性指数的合理预测对页岩油储层勘探开发进程中的水力压裂过程起到指示作用并为研究区甜点的综合评判奠定基础。从各向异性理论出发,基于线性滑动理论、散射理论以及波恩近似理论,推导了包含脆性指数、泊松比、密度、准裂缝法向弱度参数以及准裂缝切向弱度参数的HTI介质各向异性反射系数方程,并在贝叶斯框架下,期望最大化算法通过把引入隐含变量的条件期望值纳入到每次迭代时模型参数的随机模拟中,以解决模型参数的后验分布函数是隐式或者非线性时似然函数无法取极值的问题。相较于传统的最大后验概率解的求取方法,期望最大化算法的引入能够获得更稳定的模型参数反演结果,最终实现页岩油储层脆性指数与裂缝参数叠前地震直接反演。模型测试以及实际数据应用验证了本文提出的反演方法的准确性与适用性。Reasonable prediction of fracture parameters and brittleness index plays an indicative role in the hydraulic fracturing process in the exploration and development of shale oil reservoirs and lays the foundation for the comprehensive evaluation of sweet spots in a study area.Starting from the anisotropy theory,based on the linear sliding theory,scattering theory and Born approximation theory,this paper derives the anisotropic reflection coefficient equation of HTI media containing the brittleness index of Young's modulus to Poisson's ratio,Poisson's ratio,density,quasifracture normal weakness and quasi-fracture tangential weakness.And under the Bayesian framework,the expectation maximization algorithm introduces the conditional expectation value of the implicit variable into the random simulation of the model parameters at each iteration to solve the problem that the likelihood function can not take extreme values when the posterior distribution function of the model parameters is implicit or nonlinear.Compared with the traditional method of obtaining the maximum a posteriori probability solution,the introduction of the expectation maximization algorithm can obtain more stable model parameter inversion results,and finally realize the direct prestack seismic inversion of the brittleness index and fracture parameters of shale oil reservoirs.Model testing and actual data application verify the accuracy and applicability of the inversion method proposed in this paper.

关 键 词：页岩油储层 裂缝参数 脆性指数 贝叶斯理论 直接反演 

分 类 号：P631[天文地球—地质矿产勘探]