Operto S., Brossier R., Combe L., Metivier L., Ribodetti Alessandra, Virieux J. (2014). Computationally efficient three-dimensional acoustic finite-difference frequency-domain seismic modeling in vertical transversely isotropic media with sparse direct solver. Geophysics, 79 (5), p. T257-T275. ISSN 0016-8033.
Titre du document
Computationally efficient three-dimensional acoustic finite-difference frequency-domain seismic modeling in vertical transversely isotropic media with sparse direct solver
Operto S., Brossier R., Combe L., Metivier L., Ribodetti Alessandra, Virieux J.
Source
Geophysics, 2014,
79 (5), p. T257-T275 ISSN 0016-8033
The computational burden of frequency-domain full-waveform inversion (FWI) of wide-aperture fixed-spread data is conventionally reduced by limiting the inversion to a few discrete frequencies. In this framework, frequency-domain seismic modeling is performed efficiently for multiple sources by solving the linear system resulting from the discretization of the time-harmonic wave equation with the massively parallel sparse direct solver. Frequency-domain seismic modeling based on the sparse direct solver (DSFDM) requires specific design finite-difference stencils of compact support to minimize the computational cost of the lower-upper decomposition of the impedance matrix in terms of memory demand and floating-point operations. A straightforward adaptation of such finite-difference stencil, originally developed for the (isotropic) acoustic-wave equation, is proposed to introduce vertical transverse isotropy (VTI) in the modeling without any extra computational cost. The method relies on a fourth-order wave equation, which is decomposed as the sum of a second-order elliptic-wave equation plus an anellipticity correction term. The stiffness matrix of the elliptic-wave equation is easily built from the isotropic stiffness matrix by multiplying its coefficients with factors that depend on Thomsen's parameters, whereas the anelliptic term is discretized with a parsimonious second-order staggered-grid stencil. Validation of DSFDM against finite-difference time-domain modeling performed in various synthetic models shows that a discretization rule of four grid points per minimum wavelength provides accurate DSFDM solutions. Moreover, comparison between real data from the Valhall field and DSFDM solutions computed in a smooth VTI subsurface model supports that the method can be used as a fast and accurate modeling engine to perform multiparameter VTI FWI of fixed-spread data in the viscoacoustic approximation.
Plan de classement
Sciences fondamentales / Techniques d'analyse et de recherche [020]
;
Géophysique interne [066]
