Wolfberry Play, Midland Basin, West Texas.

H. Scott Hamlin and Robert W. Baumgardner
Jackson School of Geosciences University of Texas Austin

The Wolfberry Play is an unconventional oil play characterized by heterogeneous lithologies, low permeabilities, and reservoirs and source rocks in close proximity. A combination of abundant oil in place, favorable rock mechanical properties, permeable thin beds, and modern well stimulation techniques has opened the entire Lower Permian and Upper Pennsylvanian basinal intervals to production. The paleogeographic setting was a deepwater ocean basin surrounded by shallow carbonate platforms. Basin-floor stratigraphy comprises alternating layers of calcareous and siliciclastic lithofacies having widespread lateral continuities. In siliciclastic intervals, such as the Spraberry, sandstone turbidites and laminated siltstones are interbedded with organic-rich mudrocks. In calcareous intervals, such as the Wolfcamp, carbonate debris flows are interbedded with carbonate turbidites and organic-rich calcareous mudrocks. Since the late 1990s, more than 8,700 Wolfberry oil wells have been completed and have produced 216 million barrels of oil and 544 billion cubic feet of gas. Initial well production averages 30 to 125 barrels of oil per day, and ultimate per-well recovery is estimated at 100,000 to 140,000 barrels of oil equivalent. We used wireline logs to correlate and map Wolfberry intervals and cores to characterize lithofacies and calibrate logs for lithofacies identification and extrapolation beyond cored wells. This poster presents regional stratigraphic and lithologic information as a context for exploration and development of a multi-billion barrel oil resource. Wolfberry production statistics are also presented.

AAPG Search and Discovery Article #90152©2012 AAPG Southwest Section Meeting, Fort Worth, Texas, 19-22 May 2012