Regional geological framework and petroleum geology of Miocene sandstones in coastal and offshore Alabama
The Miocene natural gas trend of coastal and offshore Alabama is part of the regional Miocene oil and gas trend of the Gulf coastal area that extends from Texas into Alabama. The major Miocene productive area in Alabama is in southern Baldwin County and Mobile Bay. Since the discovery of Miocene gas in 1979, 28 natural gas fields have been established in coastal and offshore Alabama. The Miocene sandstones range in thickness from 10 to 200 ft, are very fine to coarse grained, are quartz rich, and have subangular to rounded and moderately to well-sorted quartz grains. The productive Miocene interval overlies upper Oligocene marine shelf deposits (Chickasawhay Limestone) and is overlain by Miocene fluvial clastics. The Miocene sandstones, which include the Amos, Escambia, Luce, and Meyer, are interpreted to represent a marine shelf-deltaic complex. A Miocene delta system prograded from the west in the area of offshore Louisiana-Mississippi into coastal and offshore Alabama. Reservoirs and potential reservoirs include highly constructive and highly destructive deltaic and marine shelf sandstones. Porosity in these sandstones is primary intergranular and generally ranges from 27 to 35%. Permeabilities may exceed 2000 md. Basinal Miocene marine clays and Oligocene marls are the probable petroleum source rocks. Petroleum traps are principally stratigraphic, typically involving lateral sandstone pinch-outs against regional dip. Seismic reflection is an excellent exploration tool for identifying potential Miocene fields. Miocene gas sands are best delineated with relative-amplitude seismic reflection data on which gas-charged sands are apparent as bright spots.
- Research Organization:
- Univ. of Alabama, Tuscaloosa
- OSTI ID:
- 6219447
- Report Number(s):
- CONF-870606-
- Journal Information:
- AAPG (Am. Assoc. Pet. Geol.) Bull.; (United States), Vol. 71:5; Conference: American Association of Petroleum Geologists annual meeting, Los Angeles, CA, USA, 7 Jun 1987
- Country of Publication:
- United States
- Language:
- English
Similar Records
Middle and upper Miocene natural gas sands in onshore and offshore Alabama
Paleoenvironments of the lower strata of the Tuscaloosa Group (Upper Cretaceous) of southwestern Alabama
Related Subjects
03 NATURAL GAS
ALABAMA
NATURAL GAS DEPOSITS
PETROLEUM DEPOSITS
EXPLORATION
RESERVOIR ROCK
GEOLOGIC TRAPS
OFFSHORE SITES
PERMEABILITY
SANDSTONES
TERTIARY PERIOD
CENOZOIC ERA
FEDERAL REGION IV
GEOLOGIC AGES
GEOLOGIC DEPOSITS
MINERAL RESOURCES
NORTH AMERICA
RESOURCES
ROCKS
SEDIMENTARY ROCKS
USA
020200* - Petroleum- Reserves
Geology
& Exploration
030200 - Natural Gas- Reserves
Geology
& Exploration