Geology and Infrastructure Data for the Development of Shale Gas Wells in Triassic Strata of the Deep River Basin, Lee and Chatham Counties, North Carolina, USA
The Deep River Basin is a 150-mile long northeasttrending half-graben with a steeply-dipping eastern border fault in central North Carolina. Within the Sanford sub-basin in Lee and Chatham counties, the Triassic Cumnock Formation includes a ~400- foot-thick interval of organic-rich black shale that is gas-prone and that has values of total organic carbon (TOC) in excess of 1.4% in places. Data from 28 wells (including old coal holes) and ~75 miles of seismic lines indicate that this black shale interval extends across ~25,000 acres, at depths of less than 3,000 feet. Although well drilling preceded seismic data acquisition, six of the 28 wells reported natural gas and oil shows from the Cumnock Formation, and two shut-in wells reported pressures of 900 psi and 300 psi. One of these shut-in wells (Butler No. 3) is located within 300 feet of a four-inch 800 psi natural gas distribution line.
In the Deep River Basin, many families sold the mineral rights to their property to pay for taxes during the Great Depression, and significant underground coal mining occurred in the during the 1930s. Information on mineral rights and deed transfers may be found using on-line county land records. The North Carolina oil and gas law may be viewed online at the following web site: http://www.ncleg.net (see short cut to General Statutes). Additional information on oil and natural gas in North Carolina may be found in N.C. Geological Survey Information Circular 36, which is available on-line at: www.geology.enr.state.nc.us.
AAPG Search and Discovery Article #90095©2009 AAPG Eastern Section Meeting, Evansville, Indiana, September 20-22, 2009