Oil, Natural Gas and Helium Potential of the Chupadera Mesa area, Lincoln and Socorro Counties, New Mexico
Ronald F. Broadhead
New Mexico Bureau of Geology and Mineral Resources, a division of New Mexico Institute of Mining and Technology, Socorro, New Mexico
The Chupadera Mesa region encompasses 3900 mi2 in eastern Socorro and western Lincoln Counties, central New Mexico. The area includes varied geological elements including the broad Jornada del Muerto Basin in the west, and the Oscura Mountains and Chupadera Mesa in the medial area. The Laramide-age Sierra Blanca Basin and several isolated mountain ranges formed principally by Tertiary-age igneous intrusive bodies occupy the eastern third of the region.
The Chupadera Mesa area has been sparsely drilled. A total of 45 wells have been drilled within the project area. This is a density of approximately one well for every 85 mi2. Many of the wells are shallow and reached total depth in Permian strata. Only 20 wells have been drilled to Precambrian basement. This is a density of one well per 200 mi2, or 6.4 townships. Neither oil, natural gas nor helium production have been established. Nevertheless, several of the wells have encountered promising shows of oil, natural gas, and helium.
The geology of the Chupadera Mesa area indicates favorable potential for oil and natural gas. Petroleum source rock facies are concentrated in marine Pennsylvanian strata that blanket the western two-thirds of the project area and attain a maximum thickness of 2200 ft. Dark-gray to black Pennsylvanian shales contain both gas-prone and oil-prone kerogen populations and are thermally mature to the east and west, but marginally mature in the medial area. Maturation into the oil window is caused primarily by heating associated with igneous events during the Tertiary. Favorable reservoirs are Pennsylvanian marine to marginal marine sandstones, continental sandstones of the Abo Formation (Permian: Wolfcampian), and marine to marginal marine sandstones of the Yeso Formation (Permian: Leonardian). Untested plays include speculated but undrilled late Paleozoic basins that underlie Laramide-age synclines, truncation traps in Pennsylvanian sandstones under a basal Permian unconformity at the eastern pinchout of Pennsylvanian strata, and northward pinchout of Ordovician carbonate rocks in the southern part of the project area. There is also limited coalbed methane potential in Cretaceous strata in the Jornada del Muerto and Sierra Blanca Basins.
The Chupadera Mesa project area also has favorable potential for helium. Uranium-bearing rock types favorable for the formation of radiogenic helium are present. In addition, high-angle fracture and fault systems and Tertiary-age igneous thermal events characterize the area and are favorable to the release of radiogenic helium from the Precambrian basement into the overlying Paleozoic sedimentary column. Pennsylvanian and Permian shales and Permian anhydrites and salt beds are favorable seals for helium. Analyses of gases recovered from exploratory wells drilled on Chupadera Mesa indicate the presence of helium in substantial amounts. Nonburnable gases recovered from other wells may also contain helium.