Porosity-permeability trends, Sparta B Sandstones (Eocene), Fordoche field, Pointe Coupee Parish, Louisiana

Conference · Fri Mar 01 04:00:00 EST 1991 · AAPG Bulletin (American Association of Petroleum Geologists); (United States)

OSTI ID:5800248

Krutak, P R ^[1]

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1. Louisiana State Univ., Baton Rouge (United States)

Fordoche field, Pointe Coupee Parish, Louisiana (44 wells) contains at least ten hydrocarbon-bearing zones. Major reserves of bypassed oil probably exist in the shallowest reservoir, Sparta B, estimated to contain {approximately}5.6 mm STB OIP and 2.0 bcf GIP. Sparta B pay thicknesses average 15 ft with 24.7% porosities and 200 md permeabilities. Other averages include: 7,980 PSI BHP (abnormal range), 228F BHT, 2,075 PSIG bubble point pressure, gas-oil ratio 500 SCF/bbl, oil gravities 40-44 API. Petrographic, SEM, and EDX study of 20 thin sections from these units discloses the following down-core trends and petrofacies: (1) high porosity (20-25%)-permeability (250-500+ md), fine- to very fine-grained quartzarenites whose pore throats average about 10 microns comprise the storm washover deposits. Vermicular chlorite begins to occlude porosity near the bottom of this unit (11,338.25 ft); (2) pore throats of 10-20 microns occur in quartzarenitic, upper shoreface sandstones that display slightly lower porosity and permeability than overlying units. Kaolinite and chlorite begin to occlude porosity in this facies (11,346.00 ft and 11,347.50 ft); calcite completely occludes porosity at 11,350.46 ft; (3) lower shoreface sandstones are increasingly organic, mostly very fine sand size. Organic lamellae parallel to bedding are characteristic with pore throats in the 10-15 micron-size range; chlorite and calcite occlude porosity at 11,360.50 ft and 11,365.00 ft, respectively; (4) inner shelf lithologies are very fine-grained, highly organic, micaceous, poorly sorted quartzarenites with virtually no permeability. Pore throats are small ({approximately}10 microns). Biotite occludes porosity at 11,374.67 ft, muscovite at 11,375.79 ft.

• OSTI ID: 5800248
• Report Number(s): CONF-910403--
• Conference Information: Journal Name: AAPG Bulletin (American Association of Petroleum Geologists); (United States) Journal Volume: 75:3
• Country of Publication: United States
• Language: English

Related Subjects

02 PETROLEUM
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03 NATURAL GAS
030200 -- Natural Gas-- Reserves
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58 GEOSCIENCES
580000 -- Geosciences
ALUMINIUM COMPOUNDS
ALUMINIUM SILICATES
CENOZOIC ERA
CHLORITE MINERALS
DEVELOPED COUNTRIES
ELECTRON MICROSCOPY
EOCENE EPOCH
FEDERAL REGION VI
GEOLOGIC AGES
GEOLOGIC DEPOSITS
KAOLINITE
LITHOLOGY
LOUISIANA
MICROSCOPY
MINERAL RESOURCES
MINERALOGY
MINERALS
NATURAL GAS DEPOSITS
NORTH AMERICA
OXYGEN COMPOUNDS
PERMEABILITY
PETROGRAPHY
PETROLEUM DEPOSITS
POROSITY
RESERVES
RESERVOIR ROCK
RESOURCES
ROCKS
SANDSTONES
SCANNING ELECTRON MICROSCOPY
SEDIMENTARY ROCKS
SILICATE MINERALS
SILICATES
SILICON COMPOUNDS
TERTIARY PERIOD
USA