Vertical stacking of reservoirs in Silurian carbonates of Appalachian basin

Conference · Mon Aug 01 04:00:00 EDT 1988 · AAPG Bull.; (United States)

OSTI ID:6011274

Smosna, R; Conrad, J M; Maxwell, T C

The distribution of modern reefs and oolites is controlled to a large degree by sea-floor topography. Likewise, paleotopographic highs in the Silurian Lockport Dolomite and underlying Keefer Sandstone provided optimum sites for the deposition of boundstone and grainstone reservoir facies. The Keefer Sandstone in western West Virginia was deposited as a series of subtidal sand waves with a relief of a few meters. During initial Lockport sedimentation, the turbulence, water chemistry, and light intensity were most favorable in shallow water over the Keefer sand waves, encouraging growth of coral-stromatoporoid patch reefs. Skeletal banks in the upper Lockport of eastern Kentucky also were established over topographic highs of earlier Lockport mounds. In a similar fashion, the upper Lockport of West Virginia was deposited as oolitic shoals that formed atop exposed mud mounds in the middle member. A slight rise of sea level created the agitated subtidal environment above the now-submerged mud mounds, and oolite bars developed. The reef, skeletal-bank, and oolite facies of the Lockport, and the Keefer Sandstone, are all petroleum reservoirs. Carbonate reservoirs can be identified in the subsurface by thicks on isopach maps, by their clean gamma-ray signature, and by a relatively high log porosity. Based on these criteria, seven potential fairways have been mapped in Kentucky. Because the distribution of buildups was greatly influenced by that of their predecessors, five of the fairways contain vertically stacked reservoir facies. These are particularly attractive because they can be drilled as multistory targets.

• Research Organization: West Virginia Univ., Morgantown (USA)
• OSTI ID: 6011274
• Report Number(s): CONF-8809345-
• Conference Information: Journal Name: AAPG Bull.; (United States) Journal Volume: 72:8
• Country of Publication: United States
• Language: English

Related Subjects

02 PETROLEUM
020200* -- Petroleum-- Reserves
Geology
& Exploration
03 NATURAL GAS
030200 -- Natural Gas-- Reserves
Geology
& Exploration
APPALACHIAN BASIN
CARBONATE ROCKS
GEOLOGIC DEPOSITS
GEOLOGIC FORMATIONS
GEOLOGIC STRUCTURES
GEOLOGY
MINERAL RESOURCES
NATURAL GAS DEPOSITS
PETROLEUM DEPOSITS
POROSITY
REEFS
RESERVOIR ROCK
RESOURCES
ROCKS
SANDSTONES
SEDIMENTARY BASINS
SEDIMENTARY ROCKS