Combined Geological and Surface Geochemical Methods Discover King Sand Production, Concho County, Texas

THOMPSON, C. KEITH, Recon Exploration, Inc., Dallas, TX, J. J. BROWN, Indigo Oil, Inc., Dallas, TX, and K. R. BURSON and D. F. SAUNDERS, Recon Exploration, Inc., Dallas, TX

From December, 1987 to September, 1990, 16 prospects within the current confines of the Lower King (Upper Pennsylvanian Cisco age) Sand Play in Concho County, Texas, were tested by several operators on locations found by various combinations of subsurface geology, reconnaissance surface radiometrics, and soil gas hydrocarbon leads. A 37.5% exploratory success rate has resulted in six new field discoveries or extensions with a total exploration and development cost of less than $0.50 per barrel of proven oil reserves. The average recoverable reserves per new field discovery are estimated to be 2.6 Mbbl of oil, and the average recoverable reserves per well are estimated to be 285,000 bbl at a depth of 2200 ft.

Five of the six new field discoveries were based primarily on surface geochemical data. The sixth discovery, a southeast extension to the Lonesome Dove II field, was found on the basis of subsurface geology.

The Agaritta field is one of the two largest of the new field discoveries with estimated proven (producing and undeveloped) recoverable reserves of 6 Mbbl of oil as of September, 1990. Its discovery was based on a combination of (1) detailed interstitial soil gas hydrocarbon data, (2) soil magnetic susceptibility measurements, and (3) surface potassium and uranium concentrations measured by gamma-ray spectrometry applied over two leads based on reconnaissance radiometrics. What initially appeared to be two separate prospects spaced over 7000 ft apart has since developed into one large field.

AAPG Search and Discovery Article #91004 © 1991 AAPG Annual Convention Dallas, Texas, April 7-10, 1991 (2009)