Diagenetic control on permeability baffles and barriers, Carter Sandstone, North Blowhorn Creek oil unit, Black Warrior basin, Alabama

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

OSTI ID:5804130

Kugler, R L ^[1]

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1. Geological Survey of Alabama, Tuscaloosa (United States)

Mississippian (Chesterian) Carter sandstone is the most productive oil reservoir in the Black Warrior basin of Alabama. In North Blowhorn Creek oil unit, very fine- to medium-grained quartzarenite and sublitharenite occur in an elongate, isolated northwest-southeast trending body, surrounded by shale. The sandstone was deposited in a beach-barrier environment. Most production is from ripple-laminated and horizontal- to low-angle-planar laminated shoreface and foreshore deposits in the central part of the reservoir body. Uneven distribution of diagenetic features creates permeability baffles and barriers at several scales within the reservoir, ranging from microscopic to macroscopic, and increases tortuosity of fluid flow. Early authigenic calcite and ferroan calcite occur only in shell lags deposited in channels within the reservoir body. These originally porous and permeable layers are completely cemented by calcite, ferroan calcite, and ferroan dolomite. Carbonate-cemented shell lags form discontinuous permeability barriers that may be laterally continuous between adjacent wells. Ferroan dolomite is the most abundant cement in Carter sandstone and occludes all pores near the margins of the reservoir body. The pore system within the high-quality portion of the reservoir consists of modified primary and secondary intergranular porosity and microporosity within patches of kaolinite. Porosity and permeability relationships are controlled by the distribution of quartz overgrowths, kaolinite, deformed mudstones fragments, intergranular pressure solution, and stylolite seams. The lateral extent of baffles and barriers created by these diagenetic features is related to depositional texture and ranges from micrometers to meters.

• OSTI ID: 5804130
• 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
020200* -- Petroleum-- Reserves
Geology
& Exploration
ALABAMA
CARBONIFEROUS PERIOD
DEVELOPED COUNTRIES
DIAGENESIS
GEOLOGIC AGES
GEOLOGIC DEPOSITS
GEOLOGIC FORMATIONS
GEOLOGIC HISTORY
GEOLOGIC STRUCTURES
GEOLOGY
MINERAL RESOURCES
MINERALOGY
NORTH AMERICA
PALEOZOIC ERA
PERMEABILITY
PETROLEUM DEPOSITS
PETROLOGY
RESERVOIR ROCK
RESOURCES
ROCKS
SANDSTONES
SEDIMENTARY BASINS
SEDIMENTARY ROCKS
USA