Abstract

Approximately 300 reservoirs in the New Mexico part of the Permian Basin have cumulative production of more than 1 MMBO, with a combined production from these reservoirs of 4.5 billion bbls oil as of 2000. 1 MMBO reservoirs have been grouped into 17 plays based on geologic parameters, including reservoir stratigraphy, lithology/depositional environment, and tectonic setting or trapping mechanism. The 10 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 440 MMBO, and two Ordovician plays have cumulative production of 86 MMBO. Four New Mexico plays are selected for detailed discussion based on favorable production trends, their potential for significant future growth, or new geologic information that may result in rethinking of exploration, development, and production strategies.

The Delaware Mountain Group Basinal 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 Upper San Andres and Grayburg Platform Mixed-Artesia Vacuum Trend Play contains 13 reservoirs with over 1 MMBO production, with cumulative production from these 13 reservoirs of 796 MMBO. Although much of this production has historically been from vugular porosity associated with unconformities in the upper San Andres Formation, the bulk of remaining reserves and the focus of recent development is within the less permeable Grayburg Formation.

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 354 MMBO. Stratigraphic reservoirs consist of algal mounds and associated carbonate sands. 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 is stratigraphic, resulting in an increase in the productive area and production 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 Wristen Buildups and Platform Carbonates Play has 36 reservoirs with production exceeding 1 MMBO; 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.