Play Analysis of Major Oil Reservoirs in the New Mexico Part of the Permian Basin: A Tool for Highgrading Future Exploration and Development Opportunities

BROADHEAD, RONALD F. and WILLIAM D. RAATZ¹, New Mexico Bureau of Geology and Mineral Resources, A division of New Mexico Tech, Socorro NM

¹Current address OxyPermian, Houston TX

    Approximately 300 reservoirs in the New Mexico part of the Permian Basin have cumulative production of more than 1 MMBO, with a combined cumulative production of 4.5 billion bbls oil. These reservoirs have been grouped into 16 plays based on geologic parameters, including reservoir stratigraphy, lithology/depositional environment, and tectonic setting or trapping mechanism. The 9 Permian plays have a cumulative production of 3501 MMBO, the two Pennsylvanian plays have a cumulative production of 424 MMBO, three Siluro-Devonian plays have cumulative production of 435 MMBO, and two Ordovician plays have cumulative production of 91 MMBO. Three New Mexico plays are selected for detailed discussion based on favorable production trends, their potential for significant future growth, or new information regarding their geologic age.
    The Northwest Shelf Upper Pennsylvanian Carbonate Play has been productive from 197 reservoirs, 34 of which have cumulative production of more than 1 MMBO. These 34 reservoirs have produced a combined cumulative total of 354 MMBO. Reservoirs consist of algal mounds and associated carbonate sands, and trapping mechanisms are stratigraphic. Historically, the largest reservoirs in this play yielded significant production (>10 MMBO) only decades after initial discovery. Initial development was often predicated on the presumption of structural entrapment of oil. Redevelopment proved entrapment was stratigraphic and increased the productive area of the reservoirs as well as productive rates, turning seemingly minor fields into major reservoirs. Rediscovery of the Dagger Draw reservoir in the 1990’s increased production by more than one-hundredfold and resulted in an annual production rate of more than 10 MMBO during 1996.
    The Delaware Basin Submarine Fan Sandstone Play has 155 reservoirs in New Mexico, 33 with more than 1 MMBO cumulative production. These 33 reservoirs have produced a cumulative total of 112 MMBO. Production from the New Mexico part of this play peaked in the mid-1990’s at more than 7 MMBO per year. Reservoirs are deep-water submarine-fan sandstones. Primary production via solution gas drive declines quickly as reservoir pressure is depleted. Pressure maintenance, and water flooding in selected cases, may prevent premature abandonment and increase ultimate recovery by more than 50 percent.
    The Wristen Buildups and Platform Carbonates Play has 36 reservoirs with cumulative production exceeding 1MMBO; cumulative production from these reservoirs is 369 MMBO. It has traditionally been difficult to differentiate between Siluro-Devonian Fusselman, Wristen, and Thirtyone formations in New Mexico, but recent biostratigraphy coupled with regional studies indicates that the Thirtyone is present only in extreme southeastern Lea County, placing the vast majority of traditional “Devonian” reservoirs in the Silurian Wristen play.