Chapter 9
Combined Geologic and Surface Geochemical Methods Used to Discover Agaritta, Brady Creek, Selden, and New Year '95 Fields, Concho County, Texas, U.S.A.

D. F. Saunders
Recon Exploration, Inc.
Addison, Texas, U.S.A.

K. R. Burson
Recon Exploration, Inc.
Addison, Texas, U.S.A.

J. J. Brown
Independent Geologist
Addison, Texas, U.S.A.

C. K. Thompson
Recon Exploration, Inc.
Addison, Texas, U.S.A.

ABSTRACT

From December 1987 to March 1991, several operators tested 25 prospects in the lower King sand (Upper Pennsylvanian Cisco Group) play in Concho County, Texas, U.S.A. They used combinations of subsurface geology, reconnaissance airborne gas sensing, surface radiometrics, soil magnetic-susceptibility, and soil-gas hydrocarbon measurements to define prospects. Six new King sand discoveries or extensions and three deeper Goen Limestone discoveries resulted in an estimated exploratory success rate of 36%, and the total exploration and development cost through 1998 was approximately $0.89/bbl of proven producing oil equivalent. Locations for the discovery wells on each of the successful prospects were based primarily on combined subsurface geologic and surface geochemical data.