Land full-wavefield inversion for addressing complex near-surface challenges in the Delaware Basin

We present 3-D field data examples of applying land full wave-field inversion (FWI) for addressing complex near-surface challenges in the Delaware Basin, a subbasin of the Permian Basin. Conventional velocity model building (VMB) techniques, such as travel-time refraction tomography and statics correction, are shown to be inadequate for accurately characterizing near-surface velocities, resulting in suboptimal imaging results. Clear imaging uplift is observed when land FWI is used to define the velocity model, especially for areas be low complex near-surface overburdens, such as the fill zone on the West Texas side of the Delaware Basin, as well as the shallow salt and evaporites on the New Mexico side of the Delaware Basin. We also demonstrate that in addition to imaging improvement, FWI shallow velocity models offer high-resolution details unmatched by either travel-time refraction tomography or conventional seismic migration stacks. These high-resolution features can potentially be used for detecting shallow hazards, such as karsts and faults, which can pose risks in drilling.