1. High-resolution sequence stratigraphy and petrophysics of the shale-gas resource potential in the Arkoma Basin, Oklahoma and Arkansas

Natural gas production from predominantly shale formations has become one of the most important domestic sources of clean energy during the past decade. However, the genetic stratigraphy of shale formations and the related petrophysical controls on the occurrence and production of “shale gas” are poorly understood. Research on high-resolution sequence stratigraphy of shale formations, the relation between stratigraphy and petrophysical rock properties, and the influence of these parameters on the gas potential of the Woodford (Chattanooga) and Fayetteville (Caney) Formations in the Arkoma Basin will provide the basis for assessing gas resources of this basin and will serve as an analogue for evaluating shale-gas resources of other domestic and international basins.

Ongoing development of shale-gas resources in the Arkoma Basin (Arkansas and Oklahoma) presents an unprecedented opportunity to investigate the genesis of economically important shale formations and to document geological influences on shale-gas potential. Rapid exploration and development are occurring in both the Upper Devonian – Lower Mississippian Woodford (Oklahoma) and Chattanooga (Arkansas) Formation and the Upper Mississippian Fayetteville (Arkansas) and Caney (Oklahoma) Formation. Significant questions remain unanswered regarding the stratigraphic origins and correlations of specific lithofacies within both formations, and especially regarding geologic controls of petrophysical properties, gas occurrence, and gas productivity.

This postdoctoral research will include investigation of the high-resolution sequence stratigraphy of these formations using spectral gamma-ray logging, chronostratigraphic (radiometric and biostratigraphic) analysis, and organic-inorganic geochemistry of boreholes, cores, and outcrops. This work will focus on documenting detailed stratigraphic variability that can be used to correlate specific lithofacies basin-wide and to interpret depositional and sequence-stratigraphic influences on lithofacies patterns. This will establish a foundation for investigating the petrophysical properties of the formations, including consideration of how lithofacies and chemistry influence log response and fluid flow properties. These relationships will be integrated with the results of gas-desorption and well-production tests to determine geologic influences on gas content and productivity.

Shale-gas resources in general and Arkoma Basin shale-gas resources specifically are among the most active exploration objectives in the United States. However, geologic influences on shale-gas resource potential remain poorly understood. This research will contribute to an enhanced understanding of these relationships. This research will be conducted during a new USGS assessment of Arkoma Basin petroleum resources, which will include a basin-wide evaluation of gas petroleum systems using isotope geochemistry. A close collaboration and sharing of information between this postdoctoral research and the assessment work will provide interdisciplinary feedback to establish a regional context to assure optimal and immediate application of results.

The results of this research will influence significantly evaluation of shale-gas resources in other basins, both domestically and internationally – an important result as the U.S. and the world increase natural gas usage in coming decades.

Proposed Duty Station: Reston, VA

Areas of Ph.D.: Sedimentary geology, sequence stratigraphy, basin analysis, geochemistry/mineralogy/petrology of sedimentary rocks, petrophysics

Qualifications: Applicants must meet one of the following qualifications: Research Geologist

(This type of research is performed by those who have backgrounds for the occupations stated above. However, other titles may be applicable depending on the applicant's background, education, and research proposal. The final classification of the position will be made by the Human Resources specialist.)

Research Advisor(s): David Houseknecht, (703) 648-6466, dhouse@usgs.gov; Stanley Paxton, (405) 810-4405, spaxton@usgs.gov

Human Resources Office contact: Kathy McDuffie, (703) 648-7408, kmcduffie@usgs.gov

Summary of Opportunities