Interparameter trade-off quantification and reduction in isotropic-elastic full-waveform inversion: synthetic experiments and Hussar land data set application

Journal Article · Tue May 01 00:00:00 EDT 2018 · Geophysical Journal International

DOI:https://doi.org/10.1093/gji/ggy037· OSTI ID:1473814

Pan, Wenyong ^[1]; Innanen, Kristopher A. ^[2]; Geng, Yu ^[2]

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1. Univ. of Calgary, AB (Canada). Dept. of Geoscience; Los Alamos National Lab. (LANL), Los Alamos, NM (United States)
2. Univ. of Calgary, AB (Canada). Dept. of Geoscience

The problem of inverting for multiple physical parameters in the subsurface using seismic full-waveform inversion (FWI) is complicated by interparameter trade-off arising from inherent ambiguities between different physical parameters. Parameter resolution is often characterized using scattering radiation patterns, but these neglect some important aspects of interparameter trade-off. More general analysis and mitigation of interparameter trade-off in isotropic-elastic FWI is possible through judiciously chosen multiparameter Hessian matrix-vector products. We show that products of multiparameter Hessian off-diagonal blocks with model perturbation vectors, referred to as interparameter contamination kernels, are central to the approach. We then apply the multiparameter Hessian to various vectors designed to provide information regarding the strengths and characteristics of interparameter contamination, both locally and within the whole volume. With numerical experiments, we observe that S-wave velocity perturbations introduce strong contaminations into density and phase-reversed contaminations into P-wave velocity, but themselves experience only limited contaminations from other parameters. Based on these findings, we introduce a novel strategy to mitigate the influence of interparameter trade-off with approximate contamination kernels. Furthermore, we recommend that the local spatial and interparameter trade-off of the inverted models be quantified using extended multiparameter point spread functions (EMPSFs) obtained with pre-conditioned conjugate-gradient algorithm. Compared to traditional point spread functions, the EMPSFs appear to provide more accurate measurements for resolution analysis, by de-blurring the estimations, scaling magnitudes and mitigating interparameter contamination. Approximate eigenvalue volumes constructed with stochastic probing approach are proposed to evaluate the resolution of the inverted models within the whole model. With a synthetic Marmousi model example and a land seismic field data set from Hussar, Alberta, Canada, we confirm that the new inversion strategy suppresses the interparameter contamination effectively and provides more reliable density estimations in isotropic-elastic FWI as compared to standard simultaneous inversion approach.

• Research Organization: Los Alamos National Laboratory (LANL), Los Alamos, NM (United States)
• Sponsoring Organization: Natural Sciences and Engineering Research Council of Canada (NSERC); USDOE
• Contributing Organization: Compute Canada, Toronto (Canada). Lattice cluster; Princeton Univ., NJ (United States). TIGER cluster
• Grant/Contract Number: AC52-06NA25396
• OSTI ID: 1473814
• Report Number(s): LA-UR--18-20731
• Journal Information: Geophysical Journal International, Journal Name: Geophysical Journal International Journal Issue: 2 Vol. 213; ISSN 0956-540X
• Publisher: Oxford University Press
• Country of Publication: United States
• Language: English

Related Subjects

58 GEOSCIENCES
97 MATHEMATICS AND COMPUTING
Inverse theory
Numerical modelling
Waveform inversion