Abstract

In 1984, Ed Matchus, a WTGS Life Member, and his team of Midland geologists working for both major companies and as independents, laid out a cross section based on well cuttings that captures all the stratigraphy of the Wolfberry play, WTGS 84-79 Permian Basin East to West Cross Section. It is truly a ‘Treasure – Hidden in our own back yard.’ This presentation is dedicated to Ed Matchus and his team.

The western portion of the Wolfberry play is defined as a northwest-southeast fairway delineated by the western margin of the Midland Basin and the Wolfcamp shelf edge along the eastern side of the Central Basin Platform. This fairway is evident from both regional geology and drilling activity from Gaines to Upton counties. Most operators drill and complete wells with multiple-stage fracs within the Upper Pennsylvanian, Wolfcamp, Dean, and Spraberry formations. Some operators also include completion intervals within Mississippian, Lower Pennsylvanian, and ‘Clear Fork’ formations.

The Wolfberry interval in this part of the basin represents both conventional and unconventional reservoirs within a very thick stratigraphic interval (as much as 4,000’). This interval includes Pennsylvanian to Guadalupian aged formations, which comprise slope and basinal deposits along the western margin of the Midland Basin. The Wolfberry play is unique, due to the very thick stratigraphic interval that consists of multiple lithologies deposited in various settings. The heterogeneity of numerous lithologies, depositional facies, and pore types create both challenges and opportunities for implementing effective spacing, drilling, evaluation, and stimulation techniques.

Revisiting valuable resources such as the WTGS 84-79 E-W Cross-Section allow collaboration of the knowledge of those who have preceded us with new reservoir models and advanced drilling and completion methods. Integration of these resources will improve our ability to recover more hydrocarbons from the Permian Basin. The Wolfberry Play provides vast opportunities for our profession to advance and prosper for many years to come.