Near-Surface Multiphysics Characterization Workflow for Unconventionals in the Permian Basin

In land exploration, the near surface is the first challenge to solve for accurate imaging: a sub-optimal static solution may jeopardize the subsequent processing steps. Conventional techniques for static corrections, making use of first-break arrivals only, are subject to the first-break picking quality, tend to fail in the case of a low signal-to-noise ratio, and are also challenged by the geological complexity of the near surface (e.g., velocity inversions). For these reasons, a robust workflow should consider all the available a-priori information and geophysical data that measure different properties of the same geology.

In the presented case study, three different geophysical domains are quantitatively integrated through Simultaneous Joint Inversion (SJI), which simultaneously inverts all the data sets, minimizing the joint data misfit while retaining the similarity of the inverted models in the assumption of a structural or rock-physics correlation. The workflow was designed to address geological and geophysical challenges of the Delaware Basin, West Texas, where 3D seismic and full-tensor gradiometry data were acquired over an area characterized by a complex near surface. The time imaging following the SJI-based solution showed an improved reflectivity focusing with respect to the conventional refraction result.