The Pennsylvanian Gothic Shale Gas Resource Play of the Paradox Basin
New production has been established from the Gothic Shale in the southeast portion of the Paradox Basin from the first two horizontal wells drilled in the shale. This frontier exploration project area is defined by numerous wells with gas shows in the Gothic Shale where the shale exhibits anomalous thickness. As part of this project, four vertical science wells cored the complete Gothic Shale section yielding good gas content and BTU values. The ensuing horizontal wells have initial production rates ranging from 3.1 to 5.7 MMCF/D with some associated condensate.
The Gothic Shale represents the maximum flooding surface for the third cycle of the Paradox Member of the Pennsylvanian Hermosa Formation and is found across the entire basin. The thickest Gothic Shale section is located in the southeastern and eastern portions of the basin and may represent the associated prodelta of the Silverton Delta. Elevated terrigenous quartz percentages are observed in the shale from XRD data in the distal and central portions of the prodelta where the marine environment dominates the lithology. This portion of the prodelta is where the two horizontal wells are located that have a Type II kerogen source. On the proximal side of the prodelta, the shale has a larger terrigenous influence where the source will most likely have blend of Type II and Type III kerogens
The gas shale revolution has spurred a wave of new thinking, drilling and completion technologies and a realization that giant gas fields are still undiscovered.
AAPG Search and Discovery Article #90090©2009 AAPG Annual Convention and Exhibition, Denver, Colorado, June 7-10, 2009