Application of a deep-water stratigraphic framework to the production of the Wolfcampian units in the Permian Basin

Abstract

To increase the understanding of the Wolfcampian unconventional plays within the Permian Basin, we present an integrated subsurface study shedding light on multiple target stratigraphic units (Wolfcamp A, B, C). We analyzed a rich data set covering 1000 km2 (386 mi2) in the deep-water sector (basinward of the shelf margin) of the Delaware Basin to generate a robust sequence stratigraphic framework that allows for the prediction of rock types and reservoir quality within specific sequences and improves the mapping of common-risk segments, the development options, and the landing zones in the most productive area of this super basin. These analyses consist of generating maps from seismic data and wells at basin scale (9300 km2 [35,900 mi2]), describing 29 cores, integrating 11 lithofacies and 15 petrofacies with core analyses (gamma ray, x-ray diffraction, total organic carbon, water saturation, porosity, permeability, Young’s modulus, Poisson’s ratio, compressional wave/shear wave), calibrating well log signatures to cores (gamma ray, density, neutron, resistivity), and assigning geological significance to log signatures (electrofacies). Results demonstrate how to create a simplified electrofacies model to identify the four main rock types of the basin. Interpretation includes determining time lines, correlating wells based on core analyses and calibrated log signatures, and propagating correlations to wells without cores.The stratigraphic framework, which evolved from the integration and reconciliation of multiple subsurface data sets (1) serves as a common starting point for new subsurface projects, (2) identifies the black siliceous mudstones as the best reservoir quality lithofacies and the lean dolomitic mudstone as the worst, and (3) classifies the stratigraphic beta unit as the most appropriate candidate for the development of unconventional resources.