SEQUENCE-STRATIGRAPHIC CONTROLS ON COTTON VALLEY TIGHT GAS SANDSTONES, CARTHAGE FIELD, PANOLA COUNTY, TEXAS
Published:December 01, 1997
RALPH A. WILLIAMS, ROBERT M. MITCHUM, 1997. "SEQUENCE-STRATIGRAPHIC CONTROLS ON COTTON VALLEY TIGHT GAS SANDSTONES, CARTHAGE FIELD, PANOLA COUNTY, TEXAS", Shallow Marine and Nonmarine Reservoirs: Sequence Stratigraphy, Reservoir Architecture and Production Characteristics, Keith W. Shanley, Bob F. Perkins
Download citation file:
Sequence-stratigraphic interpretation of well logs using interactive software combined with detailed production data was used to determine the reservoir architecture of the Upper Jurassic Cotton Valley Formation in the Carthage field and surrounding areas of Panola County, Texas. Seven major third-order depositional sequences were identified by correlating gamma ray and resistivity logs on 1,080 wells. Each sequence has identifiable lowstand, transgressive and highstand systems tracts. More than 30 unique tight-gas sandstone reservoir units occur in a facies spectrum of incised-valley fill, coastal plain and lagoonal facies, deltas, wave-dominated shorelines, and turbidites. Each facies has characteristic reservoir sandstone types and distributions, depending upon its depositional environment and position within sequences and systems tracts. Maps of “clean sandstone” derived from gamma ray analysis show characteristic distribution patterns and reservoir qualities for each facies. A predetermined knowledge of reservoir facies and architecture interpreted from stratigraphic sequences simplifies and reduces the costs of drilling, completion, and production.