纵波与横波反演能力对比  

Comparative analysis of seismic P⁃wave and S⁃wave inversion capabilities

作　　者：代福材 张峰[1,2] 钱忠平 孙鹏远[3,4] 邹振 李向阳[1,2,3] DAI Fucai;ZHANG Feng;QIAN Zhongping;SUN Pengyuan;ZOU Zhen;LI Xiangyang(State Key Laboratory of Oil and Gas Resources and Exploration,China University of Petroleum(Beijing),Beijing 102249,China;CNPC Key Laboratory of Geophysical Exploration,China University of Petroleum(Beijing),Beijing 102249,China;BGP Inc.,CNPC,Zhuozhou,Hebei 072750,China;National Engineering Research Center for Oil and Gas Exploration Computer Software,Beijing 100088,China)

机构地区：[1]中国石油大学(北京)油气资源与探测国家重点实验室,北京102249 [2]中国石油大学(北京)CNPC物探重点实验室,北京102249 [3]东方地球物理公司,河北涿州072750 [4]油气勘探计算机软件国家工程研究中心,北京100088

出　　处：《石油地球物理勘探》2023年第5期1284-1298,共15页Oil Geophysical Prospecting

基　　金：国家自然科学基金项目“油气地球物理”(42122029);中国石油天然气集团有限公司重点实验室项目“物探应用基础实验和前沿理论方法研究”(2022DQ0604⁃02);中国石油天然气集团有限公司科学研究与技术开发项目“三维弹性波数据处理新方法探索研究”(2021DJ3506)联合资助。

摘　　要：目前,油气地震勘探主要利用了纵波(PP波)的信息,在地层多参数反演、复杂和非常规油气储层预测、流体识别等方面存在着不确定性。近年来,横波(SV⁃SV波和SH⁃SH波)可控震源技术的发展大幅提高了资料的品质,为横波勘探技术的发展和广泛应用提供了必要条件。然而,与传统的PP波、PP与PS波联合反演相比,横波的反演能力尚不明确。为此,对比、分析不同弹性参数表示的纵波、转换横波(PSV波)和横波反射系数近似公式的精度,然后利用反射系数近似公式构建针对不同弹性参数的线性反演框架,结合反演协方差矩阵和反演条件数对比,分析纵、横波在反演不同弹性参数时的不确定性、不适定性。分析结果表明:利用PP波反演剪切模量和密度的不确定性最大,即使采用大角度数据PP波反演依然具有较高的不适定性;PSV波反演可有效降低反演的不适定性,但难以独立应用于实际资料;PP波和PSV波联合反演可有效降低反演的不确定性、不适定性,但反演效果依赖于纵、横波匹配精度;SH⁃SH波和SV⁃SV波在反演横波阻抗、横波速度、剪切模量和密度时具有明显的优势,可有效降低对输入数据角度的需求。该成果可为横波反演方法研究提供理论依据。At present,seismic exploration of oil and gas mainly uses the information of seismic P⁃wave,which has high uncertainty in the fields of multi⁃parameter inversion,complex and unconventional oil and gas reservoir prediction,and fluid identification.In recent years,the development of S⁃wave(SV⁃SV wave and SH⁃SH wave)vibroseis technology has greatly improved the quality of S⁃wave data,providing necessary conditions for the development and wide application of seismic S⁃wave exploration.However,compared with the traditional PP wave inversion and PP⁃PS wave joint inversion,the inversion ability of seismic S⁃wave is not clear.This paper first compares and analyzes the accuracy of the approximate formula of the reflection coefficient of P⁃wave,PSV wave,and S⁃wave represented by different elastic parameters and then uses the approximate formula of reflection coefficient to construct the linear inversion framework for different elastic parameters.Combining the inversion covariance matrix and the inversion condition number,this paper compares and analyzes the uncertainty and ill⁃posed nature of seismic P⁃wave and S⁃wave in the inversion of different elastic parameters.The results show that the uncertainty of shear modulus and density inversion using PP wave is the largest,and the uncertainty of PP wave inversion is still high even if using large⁃angle data.PSV wave inversion can effectively reduce the ill⁃posed nature of inversion,but it is difficult to be independently applied to actual data inversion.The joint inversion of PP wave and PSV wave can effectively reduce the uncertainty and ill⁃posed nature of inversion,but the joint inversion effect depends on the matching accuracy of P⁃wave and S⁃wave.SH⁃SH wave and SV⁃SV wave have obvious advantages in inversion of S⁃wave impedance,S⁃wave velocity,shear modulus,and density,which can effectively reduce the demand for input data angle.The results can provide a theoretical basis for the study of S⁃wave inversion methods.

关 键 词：地震横波 反演不确定性 反演不适定性 反射系数近似公式 

分 类 号：P631[天文地球—地质矿产勘探]