CHEMOSTRATIGRAPHY OF THE COLLIER-1201 CORE FROM THE WOLFCAMP FORMATION, DELAWARE BASIN, TEXAS

The early Permian (Cisuralian) Wolfcamp Formation is currently one of the most sought-after targets for petroleum production in the Permian Basin, where hydraulic fracturing technologies have made exploitation of this low-permeability and low-porosity unconventional play viable. The Permian Basin is subdivided into the Midland, Delaware, and Val Verde sub-basins by the Central Basin Platform and Ozona Arch. Subdivision of these basins resulted in different subsidence histories and more extreme deepening in the Delaware Basin. Although there is a lot of interest in these deposits, little geochemical data on the Wolfcamp Formation in the Delaware Basin is publicly available and limited data that has been published is from the much shallower Wolfcamp interval of the Midland Basin.

The Wolfcamp Formation was sampled from the core data from a pilot hole of a producing well, the Collier-1201, in the southeast Delaware Basin of Reeves County, Texas. Lithostratigraphic analysis of the core indicates that it is comprised predominantly of calcareous shale and interbedded silts with minor beds of carbonate. The inferred depositional facies for the Wolfcamp Formation is deep-water storm deposits, turbidites, and pelagic sediments. The deep-water sediments in the core along with high organic carbon content (TOC generally >1%) and organic geochemistry indicate predominantly reducing conditions in the poorly circulated deep-waters during deposition of these sediments. The use of a portable handheld energy dispersive X-Ray fluorescence (ED-XRF) unit allows for low-cost chemostratigraphic analysis. Here we evaluate the chemostratigraphic trends of the Collier-1201 core using ED-XRF as a benchmark for further geochemical characterization and correlation of the Wolfcamp Formation in the Delaware Basin.