基于角道集的各向异性全局走时层析反演方法  

Anisotropic global travel time tomographic inversion method based on ADCIGs

作　　者：熊鹰杰 刘明[1] 孟庆利[1] XIONG YingJie;LIU Ming;MENG QingLi(Research Institute of Petroleum Exploration and Development,East China Company,Sinopec,Nanjing 210000,China)

机构地区：[1]中国石化华东油气分公司勘探开发研究院,南京210000

出　　处：《地球物理学进展》2022年第6期2469-2480,共12页Progress in Geophysics

基　　金：中国石化科技开发部项目“常压页岩气地球物理评价技术研究”(P21087-3)资助。

摘　　要：当今的油气勘探工作中,叠前深度偏移成像技术由于其高精度的优点在工业中得到了广泛应用.然而,叠前深度偏移成像质量依赖于速度模型的精度,层析速度反演是实际生产中最常用的速度反演方法之一,传统的全局网格层析反演方法属于反射波层析.它虽然可以全局行反演,但浅层速度的准确性远不如初至波层析反演,并且忽略了误差由浅层至深层的积累以及地下介质的各向异性.除此之外,在缺少层位约束的情况下很难还原出速度模型本来的形态.而基于“层剥离”的各向异性层析反演方法虽然可以减小误差的积累,但其反演效率也大大降低.为此,本文提出了一种基于角道集的各向异性全局层位约束的走时层析反演方法,在计算累计误差的同时全局更新速度模型,并将初至波层析反演出的浅层速度模型融合到了初始速度模型中,提高了模型精度以及全局层析的效率.简单模型试算结果证明了方法的正确性,复杂模型试算结果证明了适用性.In today’s oil and gas exploration work,pre-stack depth migration imaging technology has been widely used in industry due to its high accuracy.However,the accuracy of the velocity model is critical to the pre-stack depth migration algorithm.Tomographic velocity inversion is one of the most commonly used velocity inversion methods in actual production.The traditional global grid tomography inversion method belongs to reflected wave tomography.Although it can be inverted globally,the accuracy of shallow velocity is far less than the inversion result of the first break tomographic inversion.It ignores the accumulation of errors from shallow to deep and the anisotropy of the underground medium.On the contrary,the anisotropic tomographic inversion method based on“layer stripping”can reduce the accumulation of errors,but its inversion efficiency is greatly reduced,For this reason,this paper proposes an anisotropic global travel time tomographic inversion method based on ADCIGs,which can update the velocity model globally and update a target area individually,the shallow velocity model inverted by the first break tomographic inversion which is fused into the initial velocity model obtained from conventional velocity analysis,improve the accuracy of the model and the efficiency of global tomography.The numerical test of the simple model proves the correctness of the method,and the test of the complex model proves the applicability.

关 键 词：速度融合 各向异性 全局层析 角道集 逆时偏移 

分 类 号：P631[天文地球—地质矿产勘探]