Lower Permian grainstone reservoirs, southern Tatum basin, southeastern New Mexico
Lower Permian carbonates of the southern Tatum basin, southeastern New Mexico, are characterized by shoaling-upward carbonate cycles of which grainstones are an integral part. Bioclastic (most common) and oolitic grainstones usually occur as the capping phase of phylloid algal mounds in these cycles and occasionally as thin shoals on the open shelf. The grainstones are important hydrocarbon reservoirs in the phylloid mound complexes of the study area. Thickness ranges from 2 to 10 ft (60 cm to 3 m) and averages of 4-6 ft (1.2-2 m). Average size is usually 1-2 mi/sup 2/ (2.6-5.2 km/sup 2/). The traps are primarily stratigraphic and are formed by the lateral pinch-out into nonporous bioclastic wackestone adjacent to the phylloid algal mounds. The seal is usually the transgressive mudstone and black shale at the base of the next cycle or nonporous bioclastic wackestone. Porosity averages 5-10%, with primary interparticle, biomoldic, and oomoldic as the most common types. Primary intraskeletal is a minor fourth type. Porosity reduction by marine and meteoric phreatic cementation has occurred in places. Porosity development is dependent on subaerial exposure, which results from phylloid algal mound complexes localized on paleobathymetric high areas on subtle paleostructures. Isolated shelf grainstones and these low on the flanks of mound complexes are completely cemented with sparry calcite.
- Research Organization:
- BelNorth Petroleum Corp., Midland, TX
- OSTI ID:
- 7176111
- Report Number(s):
- CONF-8604186-
- Journal Information:
- Am. Assoc. Pet. Geol., Bull.; (United States), Journal Name: Am. Assoc. Pet. Geol., Bull.; (United States) Vol. 70:3; ISSN AAPGB
- Country of Publication:
- United States
- Language:
- English
Similar Records
Depositional environments and porosity development, Strawn Formation (middle Pennsylvanian), Wagon Wheel and HSA (Penn) fields, west Texas
Depositional environments, diagenetic history, and reservoir characteristics of upper Smackover at Eustace field, Henderson County, Texas
Related Subjects
020200* -- Petroleum-- Reserves
Geology
& Exploration
03 NATURAL GAS
030200 -- Natural Gas-- Reserves
Geology
& Exploration
CARBONATE ROCKS
FEDERAL REGION VI
GEOLOGIC DEPOSITS
GEOLOGIC FORMATIONS
GEOLOGIC STRUCTURES
MINERAL RESOURCES
NATURAL GAS DEPOSITS
NEW MEXICO
NORTH AMERICA
PETROLEUM DEPOSITS
POROSITY
RESERVOIR ROCK
RESOURCES
ROCKS
SEDIMENTARY BASINS
SEDIMENTARY ROCKS
USA