Lithofacies, Depositional Environment and Burial History of the Barnett Shale in the Delaware Basin, Pecos Co. West Texas, and comparison with the Barnett Shale in the Fort Worth Basin

Authors: Walaa Ali, Julia F. W. Gale, Stephen C. Ruppel, and Robert G. Loucks

Venue: West Texas Geological Society Symposium, in Midland, Texas September 10-12, 2008. http://www.wtgs.org [external site]

Abstract: This study sets out to expand our knowledge of the Barnett Shale beyond the Fort Worth Basin, where it has been a very successful shale-gas reservoir, into the Delaware Basin where it has further shale-gas potential. Core is described from the Barnett Shale in Pecos County, and lithofacies and depositional environment are interpreted for the Mississippian in this area in the context of what is known about the Mississippian in the Fort Worth Basin. Logs and production data are shown for this and other wells used in the study. The 1-D burial history for the cored well is modeled using ‘Genesis’ software, making use of published USGS data on thermal maturity from vitrinite reflectance. This model is combined with other published burial history models and structural interpretations to create a more regional model for the Delaware Basin and Central Basin Platform. Constraining the burial history is crucial for being able to map the likely diagenetic changes in the shale with time. These in turn control hydrocarbon generation, over pressuring, natural fracturing, petrology and petrophysics, and present day mechanical rock properties, all of which are important factors in determining whether Barnett shale-gas in the Delaware Basin will be economic.

Related NETL Project
This presentation is related to the NETL project DE-FC26-04NT15509, "Integrated Synthesis of the Permian Basin: Data and Models for Recovering Existing and Undiscovered Oil Resources from the Largest Oil-Bearing Basin in the U.S." The objectives of the project are twofold: (1) to produce a detailed, comprehensive analysis and history of Paleozoic depositional and reservoir systems in the Permian Basin, and (2) to create spatially integrated databases of depositional, stratigraphic, lithologic, and petrophysical properties for selected reservoir plays and stratigraphic horizons. These objectives will be undertaken and completed sequentially during the 3 years of the project. The overall objective is to provide Permian Basin operators with (a) outcrop and subsurface reservoir specific data, data syntheses, and models to be applied to geological, engineering, and completion-based redevelopment of existing reservoirs, and (b) a detailed regional stratigraphic framework for applying such models to new exploration targets.

Project Contacts
NETL – Virginia (Ginny) Weyland (Virgina.Weyland@netl.doe.gov or 918-699-2041)
Bureau of Economic Geology, University of Texas at Austin – Stephen C. Ruppel (stephen.ruppel@beg.utexas.edu or 512-471-1534)