Full waveform inversion in acoustic orthorhombic media and application to a North Sea data set
KAUST DepartmentEarth Science and Engineering Program
Physical Science and Engineering (PSE) Division
Seismic Wave Analysis Group
Online Publication Date2018-07-18
Print Publication Date2018-09
Permanent link to this recordhttp://hdl.handle.net/10754/628446
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AbstractFull-waveform inversion (FWI) in anisotropic media is challenging, mainly because of the large computational cost, especially in 3D, and the potential trade-offs between the model parameters needed to describe such media. By analyzing the trade-offs and understanding the resolution limits of the inversion, we can constrain FWI to focus on the main parameters the data are sensitive to and push the inversion toward more reliable models of the subsurface. Orthorhombic anisotropy is one of the most practical approximations of the earth subsurface that takes into account the natural horizontal layering and the vertical fracture network. We investigate the feasibility of a multiparameter FWI for an acoustic orthorhombic model described by six parameters. We rely on a suitable parameterization based on the horizontal velocity and five dimensionless anisotropy parameters. This particular parameterization allows a multistage model inversion strategy in which the isotropic, then, the vertical transverse isotropic, and finally the orthorhombic model can be successively updated. We applied our acoustic orthorhombic inversion on the SEG-EAGE overthrust synthetic model. The observed data used in the inversion are obtained from an elastic variable density version of the model. The quality of the inverted model suggests that we may recover only four parameters, with different resolution scales depending on the scattering potential of these parameters. Therefore, these results give useful insights on the expected resolution of the inverted parameters and the potential constraints that could be applied to an orthorhombic model inversion. We determine the efficiency of the inversion approach on real data from the North Sea. The inverted model is in agreement with the geologic structures and well-log information.
CitationMasmoudi N, Alkhalifah T (2018) Full-waveform inversion in acoustic orthorhombic media and application to a North Sea data set. GEOPHYSICS 83: C179–C193. Available: http://dx.doi.org/10.1190/geo2017-0738.1.
SponsorsThe authors would like to thank Statoil ASA and the Volve license partners ExxonMobil E&P Norway AS and Bayerngas Norge AS, for the release of the Volve data. The views expressed in this paper are the views of the authors and do not necessarily reflect the views of Statoil ASA and the Volve field license partners. The authors would like to thank M. Houbiers from Statoil, who gave some helpful suggestions. For computer time, this research used the resources of the Supercomputing Laboratory at King Abdullah University of Science & Technology (KAUST) in Thuwal, Saudi Arabia. We also acknowledge the valuable comments from three anonymous reviewers that significantly improved the quality of this manuscript. We are also grateful to S. Feki and B. Hadri from the KAUST Supercomputing Laboratory for many useful discussions. We also thank KAUST for financial support, J.-W. Oh for generating the synthetic data, and SWAG members at KAUST for the collaborative environment.
PublisherSociety of Exploration Geophysicists