Petroleum Geology of Pennsylvanian and Lower Permian Strata, Tucumcari Basin, East-Central New Mexico: ABSTRACT

Abstract

The Tucumcari basin of east-central New Mexico is a structural depression that existed as a depositional basin from Strawn (Middle Pennsylvanian) until late Wolfcampian (Early Permian) time. Depth to Precambrian ranges from 6500 ft to more than 9000 ft. High-angle faults form the north, east, and west edges of the basin. No major structural discontinuities separate the basin from a shallow shelf to the south. Faults cut Pennsylvanian and Wolfcampain strata but generally do not offset post-Wolfcampian strata. Faults and regional structure control facies and thickness patterns within the Pennsylvanian and Wolfcampian. Coarse arkosic sands in the Pennsylvanian and Wolfcampian are good reservoirs. Those sands were deposited in northern and western parts of the basin and were derived from highlands of Precambrian granitic rocks that formed the northern and western margins of the basin. High-energy limestones are possible reservoirs in the southern part of the basin. Porous Wolfcampian dolostones cover the Frio uplift on the east side of the basin. Pennsylvanian and Wolfcampian marine shales and micritic limestones are source rocks within the Tucumcari basin. Post-Wolfcampian strata are thermally immature. Two presently noncommercial pools of oil and gas, the Latigo Ranch pool and the T-4 Ranch pool, have been discoveredmore » in Strawn sands in the northern part of the Tucumcari basin. Oil generated in the upper Paleozoic has migrated vertically into the Triassic; two oil accumulations, the Santa Rosa tar sands and the Newkirk oil pool, are in Triassic sandstones and have combined reserves of 153 million bbls of oil.« less