摘要
AVA三参数反演在地层弹性参数预测中发挥着重要作用。由于AVA理论公式(即物理先验认识)中的角度不易确定,加之大型稀疏矩阵的病态性,导致常规叠前反演过程不稳定。为此,提出物理、数据先验认识融合的叠前解耦分步反演方法。首先,基于物理先验认识构建非稀疏正演框架,以增加参数反演的稳定性,为解耦分步反演奠定基础;然后,以井资料为数据先验认识,将物理、数据先验认识融合,对叠前地震数据进行解耦,以得到更准确的叠前地震属性数据;最后,对解耦后的叠前地震属性进行反演得到地层弹性参数。该方法通过井数据先验认识修正反演过程,可以避免因物理先验认识中角度不准带来的误差。实际数据测试结果表明,相比于业界三参数AVA反演方法,本方法的反演结果具有更高的精度,其中拉梅参数、剪切模量和密度的精度分别提高14.1%、13.6%和11.9%。
Amplitude⁃versus⁃angle(AVA)inversion plays an important role in the prediction of reservoir elastic parameters.The angles of the AVA equation(physical prior knowledge)are not easily determined,and the ill⁃posed nature of the large sparse matrix will make the conventional prestack inversion procedure unstable.For this reason,a prestack decoupled stepwise inversion method harmonized with physical and data prior knowledge is proposed.Firstly,a non⁃sparse forward framework is established based on physical knowledge to increase the stability of parameter inversion and lay the foundation for decoupled stepwise inversion.Next,this paper takes well data as data prior knowledge and harmonizes it with physical and data prior knowledge to decouple the prestack seismic data for more accurate prestack seismic attributes.Finally,inversion of decoupled prestack seismic attributes is performed to get the reservoir elastic parameters.This method can correct the inversion procedure by well logging prior information,which can avoid the errors caused by the inaccurate angles in the physical prior knowledge.The actual data test results show that the inversion results of the proposed method have higher accuracy compared with the industrial AVA inversion method.In addition,the inversion results of this method have higher accuracy,in which the accuracy of the lame parameter,shear modulus,and density is improved by 14.1%,13.6%,and 11.9%,respectively.
作者
张繁昌
吴继安
兰南英
ZHANG Fanchang;WU Jian;LAN Nanying(National Key Laboratory of Deep Oil and Gas,China University of Petroleum(East China),Qingdao,Shandong 266580,China)
出处
《石油地球物理勘探》
EI
CSCD
北大核心
2024年第2期250-259,共10页
Oil Geophysical Prospecting
基金
国家自然科学基金项目“裂缝型储层五维地震解释理论与方法研究”(4203013)资助。
关键词
解耦分步反演
物理先验认识
数据先验认识
叠前地震属性
decoupled stepwise inversion
physical prior knowledge
data prior information
prestack seismic attribute
