Petrophysical challenges with mudrocks in the Permian Basin: New concepts and workflows

Petrophysical evaluation is fundamental to geologic understanding of the basin, resource assessment, and development. We focus on some of the major challenges to the petrophysical evaluation of tight mudrock reservoirs, with examples from the Permian Basin. We list some major challenges, especially those dealing with wireline logs. We develop new methods and show results from an integrated petrophysical characterization of the Wolfcamp, Bone Spring, and Spraberry formations in the Permian Basin. These workflows include new data acquisition (core, log, and fluid), petrophysical inversion modeling, and new machine learning (ML) concepts to derive reservoir and elastic properties of mudrocks. These workflows provide additional insights to geologic system (rock composition, heterogeneities, and water salinity). We propose petrophysical workflows used in such systems be multi-tiered and evergreen, depending on new concepts, data, and methods.