ABSTRACT: Reservoir Recognition in Mississippian Chappel Formation, Hardeman County, Texas

M. D. Allison

Fenestrate bryozoan banks are developed in the Chappel formation of the Mississippian in Hardeman County, Texas. Three recognizable facies exist in the Chappel: bank core, bank flank, and interbank. Recognition of what facies is present during drilling is critical in determining the proximity of the well bore to a potential reservoir.

Hydrocarbon reservoirs within the Chappel formation have been found in porous core-facies limestones and dolomites, and, in rare cases, in porous cherts. Porosity is primarily of a vuggy, intercrystalline, and fracture type. Porous intervals bordering on cavernous have been recognized.

Exploration for reservoirs in the Chappel has been conducted in the past by both geophysical and geological techniques. By understanding the nature of the reservoir, geological and geophysical exploration techniques can be tailored to better fit the objective.

AAPG Search and Discovery Article #90096©1990 AAPG Southwest Section Meeting, Wichita Falls, Texas, March 11-13, 1990