Case History and Early Development of the Fayetteville Shale

Curtis P. Conrad. Senior Staff Geologist, Southwest Energy, Houston, TX

The Fayetteville Shale is a Mississippian-age shale that is the geologic equivalent of the Caney Shale in Oklahoma and the Barnett Shale in North Texas. Early recognition of conventional tight sandstone reservoirs in the traditional Arkoma basin plays producing more gas than could be volumetrically calculated (the ÒWedington IncongruityÓ) led to the inception of the Fayetteville Shale play. The Fayetteville Shale is laterally extensive across several counties within the Arkoma basin with production already established over an area encompassing approximately 400,000 of the companyÕs 890,000 net acres at year-end 2006.

The thickness of the Fayetteville Shale ranges from less than 50 feet in the western portion of the play to over 500 feet in the eastern portion. Thermal maturity ranges from 1.5 to 4.5 with total organic carbon values from 4.5 to 9.5%. Productive Fayetteville shale wells have porosities in the 8% range with 100Ð400 nanodarcy permeabilites. Drill depths of the Fayetteville Shale range from 1,500 to 6,000 feet.

This presentation will focus on what the Fayetteville shale play is, how the idea of the play was developed, and the geologic focus applied to help guide Southwestern EnergyÕs exploration and development efforts to date.