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The AAPG/Datapages Combined Publications Database

Four Corners Geological Society


Natural Fracture Systems in the Southern Rockies, 1999
Pages 129-129

Abstract: The Productive Potential From Fractured Reservoirs in the Carlile Shale of the San Juan Basin

Alan P. Emmendorfer1

The Mancos Formation has been and continues to be a prolific producer of oil from fractured shale reservoirs within the San Juan Basin. While vertical pool limits vary from field to field, most of the production is credited to the El Vado Sandstone Member of the Niobrara Shale, considered the primary exploratory target and productive zone.

Lying below the El Vado Sandstone and often overlooked for its productive potential is the Carlile Shale. This unit is comprised of interbedded sandstones, siltstones, and shales and is commonly divided into the Lower Carlile, Juana Lopez, and the Upper Carlile. Much of this interval is calcareous in nature and when placed in the proper structural position is susceptible to fracturing or tectonic dolomitization. Data exists to show the stand alone productive nature of fractured reservoirs in the Carlile shale from varying structural positions. Examples of production in excess of 40,000 Barrels of Oil from wells in the Verde Gallup Field located on the Hogback Monocline and from a northwest trending structural feature in the Bisti suggests additional reserves await development.

The recognition of the potential for fractured reservoir development within the Carlile Shale is important in the exploration for new fractured reservoirs and as a plugback target in depleted wells in the mature San Juan Basin. In addition, the Carlile Shale offers a shallow exploration target on the Four Corners Platform where the Mancos Formation crops out over much of the area.

Acknowledgments and Associated Footnotes

1 Coleman Oil & Gas, 5107 Budding Lane, Farmington, New Mexico 87402

Copyright © 2011 by the Four Corners Geological Society