PSPlay Analysis and Digital Portfolio of Major Oil Reservoirs in the Permian Basin: New Mexico*
By
Ronald F. Broadhead1, William D. Raatz2, Shirley P. Dutton3, and Eugene M. Kim3
Search and Discovery Article #10065 (2004)
*In conjunction with: U.S. Department of Energy. Adapted from poster presentation at AAPG Annual Meeting, Dallas, Texas, April 18-21, 2004.
1New Mexico Bureau of Geology and Mineral Resources, a division of New Mexico Tech, Socorro, NM 87801 (ron@gis.nmt.edu)
2New Mexico Bureau of Geology and Mineral Resources; present address: OxyPermian, Houston, TX
3Bureau of Economic Geology, University of Texas at Austin, Austin, TX 78713
Approximately 300 reservoirs in the New Mexico part of the Permian Basin have cumulative production of more than 1 MMBO, with a combined production of 4.5 billion bbls oil as of 2000. Reservoirs with 1 MMBO cumulative production have been grouped into 17 plays based on geologic parameters, including reservoir stratigraphy, lithology, depositional environment, tectonic setting, and 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 a cumulative production of 440 MMBO. The two Ordovician plays have a cumulative production of 86 MMBO. Four New Mexico plays are selected for detailed discussion based on favorable production trends, potential for significant bypassed pay, possibilities for enhanced production, or rethinking of exploration concepts 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 Artesia Vacuum Trend Play contains 13 reservoirs with more than 1 MMBO production. These 13 reservoirs have produced a cumulative total of 796 MMBO. Although much of this production has historically been from vugular porosity in carbonates of the upper San Andres Formation, significant reserves remain that may be produced by horizontal drilling to tap underproduced reservoir compartments in established San Andres reservoirs as well as targeting bypassed, behind-pipe pay within the less permeable sandstone of the Grayburg Formation.
The Leonard Restricted Platform Carbonate Play has 34 reservoirs with production exceeding 1 MMBO. Cumulative production from these reservoirs is 431 MMBO. Reservoirs consist of limestones and dolostones deposited on a restricted carbonate platform; associated platform sandstones are also productive. Traps are formed by wide, low-relief anticlines. Uneven pay distribution across structures and strata-limited fracture systems have compartmentailzed reservoirs and resulted in bypassed pay that may be tapped through horizontal drilling.
The Northwest Shelf Upper Pennsylvanian Carbonate Play has been productive from 197 reservoirs, 34 of which have produced more than 1 MMBO. These 34 reservoirs have produced a combined 354 MMBO. Reservoirs consist of algal mounds and associated carbonate sands. Trapping mechanisms are largely stratigraphic. Historically, the largest reservoirs in this play yielded significant production (>10 MMBO cumulative) 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 reservoirs into major ones. 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.