Linearized waveform inversion for vertical transversely isotropic elastic media:Methodology and multi-parameter crosstalk analysis  

作　　者：Ke Chen Lu Liu Li-Nan Xu Fei Hu Yuan Yang Jia-Hui Zuo Le-Le Zhang Yang Zhao 

机构地区：[1]National Key Laboratory of Petroleum Resources and Engineering,Unconventional Petroleum Research Institute,China University of Petroleum(Beijing),Beijing,102249,China [2]Aramco Beijing Research Center,Aramco Asia,Beijing,100102,China [3]University of Lausanne,Lausanne,CH-1015,Switzerland [4]Bureau of Geophysical Prospecting,China National Petroleum Corporation,Zhuozhou 072750,Hebei,China

出　　处：《Petroleum Science》2024年第1期252-271,共20页石油科学（英文版）

摘　　要：Seismic migration and inversion are closely related techniques to portray subsurface images and identify hydrocarbon reservoirs.Seismic migration aims at obtaining structural images of subsurface geologic discontinuities.More specifically,seismic migration estimates the reflectivity function(stacked average reflectivity or pre-stack angle-dependent reflectivity)from seismic reflection data.On the other hand,seismic inversion quantitatively estimates the intrinsic rock properties of subsurface formulations.Such seismic inversion methods are applicable to detect hydrocarbon reservoirs that may exhibit lateral variations in the inverted parameters.Although there exist many differences,pre-stack seismic migration is similar with the first iteration of the general linearized seismic inversion.Usually,seismic migration and inversion techniques assume an acoustic or isotropic elastic medium.Unconventional reservoirs such as shale and tight sand formation have notable anisotropic property.We present a linearized waveform inversion(LWI)scheme for weakly anisotropic elastic media with vertical transversely isotropic(VTI)symmetry.It is based on two-way anisotropic elastic wave equation and simultaneously inverts for the localized perturbations(ΔVp_(0)/Vp_(0)/Vs_(0)/Vs_(0)/,Δ∈,Δδ)from the long-wavelength reference model.Our proposed VTI-elastic LWI is an iterative method that requires a forward and an adjoint operator acting on vectors in each iteration.We derive the forward Born approximation operator by perturbation theory and adjoint operator via adjoint-state method.The inversion has improved the quality of the images and reduces the multi-parameter crosstalk comparing with the adjoint-based images.We have observed that the multi-parameter crosstalk problem is more prominent in the inversion images for Thomsen anisotropy parameters.Especially,the Thomsen parameter is the most difficult to resolve.We also analyze the multi-parameter crosstalk using scattering radiation patterns.The linearized waveform inversion for

关 键 词：ELASTIC ANISOTROPY Least-squares imaging Waveform inversion Computational geophysics 

分 类 号：P631.4[天文地球—地质矿产勘探]