Application of full waveform inversion on Alaska land 3D survey

Abstract

For land surveys, the near-surface velocity model is the key to acquiring a correct statics solution and an accurate depth model. Obtaining an accurate near-surface model is challenging because of strong surface waves, complicated near-surface geology, and a lack of offsets for reflectionbased tomography. Traditionally, first-arrival tomography has been the standard tool for obtaining near-surface velocities in land seismic surveys, but it relies heavily on the first break picking. Theoretically, full waveform inversion (FWI) can provide a more accurate, highresolution weathered model. We designed a practical workflow to apply 3D isotropic acoustic FWI on a 3D land survey in Alaska to obtain a high-resolution weathered layer model. We observed that the FWI model provides many details related to the near-surface geology, improves the focusing of the migrated image, and reduces residual curvature of the common image gathers.