Permeability estimated from subsurface data: Grayburg Formation, Dune field, Crane County, west Texas

Conference · Sat Jan 31 23:00:00 EST 1987 · AAPG Bulletin (American Association of Petroleum Geologists); (USA)

OSTI ID:5406294

Lucia, F J ^[1]

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1. Bureau of Economic Geology, Austin, TX (USA)

Dune field contains little vuggy porosity so total porosity and particle size become the determining factors. Three pore-geometry families are distiguished: intergranular porosity between 300-{mu}m grains in grainstones, intercrystalline porosity between 50-{mu}m dolomite crystals in dolomitized wackestones/packestones, and rocks with an intimate mixture of these two end members. Unique porosity-permeability transform functions for these three pore-type families are determined. The presence of up to 55% gypsum in Dune field complicates calculations of total porosity. Particle size was determined by relating particle size to irreducible water saturation. In the oil column, irreducible water saturation is a function of interparticle porosity and particle size. Assuming similar porosity values, rocks with finer pores will have higher water saturations than those with larger pores. In Dune field, intergranular pores are larger than the intercrystalline pores, and saturation values calculated from wireline logs show lower water saturations for the intergranular pore-type families than for the intercrystalline pore-type families. The mixed family is intermediate. Permeabilities are calculated from sonic and resistivity logs by determining the pore-type family from the saturation values and the permeability from the porosity-permeability relationship for that family. The resulting permeability profiles compare favorably with core analysis profiles. Permeability logs are correlated assuming parallel beds, and permeability cross sections and permeability-thickness maps are prepared. The results show that the reservoir can be divided into upper and lower members separated by a 25-ft permeability barrier. The permeability in either member varies on scales from 600 ft to 1 mi and can be related to depositional and diagenetic facies.

• OSTI ID: 5406294
• Report Number(s): CONF-8703189--
• Journal Information: AAPG Bulletin (American Association of Petroleum Geologists); (USA), Journal Name: AAPG Bulletin (American Association of Petroleum Geologists); (USA) Vol. 71:2; ISSN AABUD; ISSN 0149-1423
• Country of Publication: United States
• Language: English

Related Subjects

02 PETROLEUM
020200* -- Petroleum-- Reserves
Geology
& Exploration
ALKALINE EARTH METAL COMPOUNDS
CALCIUM CARBONATES
CALCIUM COMPOUNDS
CARBON COMPOUNDS
CARBONATE MINERALS
CARBONATE ROCKS
CARBONATES
DIAGENESIS
DOLOMITE
FEDERAL REGION VI
GEOLOGIC DEPOSITS
MAGNESIUM CARBONATES
MAGNESIUM COMPOUNDS
MAPPING
MINERAL RESOURCES
MINERALS
NORTH AMERICA
OIL FIELDS
OXYGEN COMPOUNDS
PERMEABILITY
PETROLEUM DEPOSITS
POROSITY
RESERVOIR ROCK
RESOURCES
ROCKS
SEDIMENTARY ROCKS
TEXAS
USA
WELL LOGGING