Amplitude-variation-with-offset inversion based on group sparse regularization

Abstract

Seismic amplitude variation with offset (AVO) inversion from pre-stack seismic data plays a significant role in estimating the elastic parameters and characterizing reservoir properties. Generally, sparse regularization is widely used to solve ill-posed inverse problems by reducing the solution space of subsurface parameters, which makes seismic AVO inversion more stable. However, the traditional sparse constraint inversion only focuses on the vector sparsity of reflectivity, instead of the structural sparse characteristics of estimated parameters. Consequently, various elastic parameters demonstrate different formation structural features in the same location of stratum. In this study, we propose a novel approach that combines the structural sparsity and the vector sparsity of the model reflectivity to establish the posterior probability density distribution and solve the objective function of model parameters. Based on the relationship among multiple elastic parameters, we divide the model parameters to be inverted into several groups according to intrinsic structural sparse characteristics of elastic parameters. In this case, all model parameters at the same sampling point are classified into the identic group, which ensures that different estimated parameters show the same characteristic in terms of stratigraphic structure. From the perspective of Bayesian inference, we utilize the modified Cauchy Probability Density Function (PDF) to characterize the group sparsity and describe the relationship among model parameters in the same group by Gaussian PDF. Furthermore, we estimate the optimum solution corresponding to the maximum posteriori probability under Bayesian inference. Synthetic experiments on Marmousi model prove that the estimated P-velocity, S-velocity and density are consistent with those of the real models, and the application of field data confirms the availability and feasibility of group sparse inversion.

Characterization and analysis of attenuation anisotropy in viscoelastic vertical transverse isotropic media

“…Seismic inversion based on the quasi-Zoeppritz equation and reflection coefficient approximation is an important geophysical method for reservoir characterization and fluid identification (Chen et al, 2022;Li et al, 2020;Xi et al, 2021;Yin et al, 2015Yin et al, , 2018. Unfortunately, thorough explanations of attenuation characteristics in a viscoelastic anisotropic medium based on the reflection coefficient equation are few.…”

Seismic Response Models and the AVO Simulation of Coal-Bearing Reservoirs

“…AVO analysis is often conducted to analyse and invert the subsurface's lithological structure by evaluating how the characteristics of reflection amplitudes vary with offset to describe and detect oil and gas reservoirs [27,28]. Different stratigraphic structures and lithological combinations correspond to different AVO types.…”