Elastic full waveform inversion on land data acquired with dispersed source arrays

Abstract

Summary The absence of low-frequency information in real field seismic data prevents Full Waveform Inversion (FWI) applications from obtaining smoothed velocity model for accurate seismic imaging. In addition, for land datasets, FWI with acoustic wave equation is not suitable in describing wave propagations to accommodate surface and converted waves. The seismic data used in this paper was acquired in Saudi Arabia by using an acquisition configuration based on dispersed source arrays having three different frequency bands, namely, 1.5 to 8 Hz, 6.5 to 54 Hz and 50 to 87 Hz. Alternatively, elastic FWI is applied for the estimation of three parameters, namely, the P-wave, S-wave velocities and density to one of this dataset containing 1.5 to 8 Hz. In an algorithm of elastic FWI, wave modeling is performed in the time domain by the first-order wave equation with the staggered grid scheme while other procedures such as calculating the partial derivative wavefields are conducted in the Laplace- or Laplace-Fourier domains based on the second-order wave equation with the finite element method. To demonstrate the validity of the elastic FWI, acoustic reverse time migration was implemented on the initial and inverted P-wave velocities with the data containing 6.5 to 54 Hz.