A regional assessment of residual oil zones in the Permian Basin and their potential for carbon dioxide capture usage and storage

Residual Oil Zones (ROZs) are a growing subject of both as a potentially large new energy resource and an opportunity for Carbon Dioxide (CO2) Capture Utilization and Storage (CCUS). Defined here as thick volumes of rock containing near-residual saturations of predominantly immobile oil resulting from the natural imbibition of water into an oil-filled reservoir, ROZs by nature can only be commercially produced via tertiary recovery techniques primarily CO2 enhanced oil recovery. This study focuses on ROZs in Permian Basin from a regional perspective to provide independent analysis on the potential of ROZs as a CCUS target in the study area. Based on an understanding of Permian Basin ROZs were likely formed by regional hydrodynamic forces, this study identifies crude oil sulfur content as a viable proxy for ROZ presence. Mapping and interpolation of crude oil sulfur content reveals a broad stratigraphic and spatial distribution of potential ROZ existence across the Permian Basin. These results support the position that ROZs present large targets for CCUS activity in the Permian Basin and may be prevalent in hydrocarbon basins worldwide with similarly dynamic fluid migration histories. (C) 2014 The Authors. Published by Elsevier Ltd.