Exploration and Development Overview for the Fayetteville Shale Gas PlayÑ

 North-Central Arkansas

Michael (Ed) Ratchford. Arkansas Geological Commission, Little Rock, AR 

[email protected]

The Mississippian Fayetteville Shale is present in the subsurface across a large portion of northern Arkansas and is the focus of an intensive shale-gas exploration and development campaign by several energy companies. Approximately 2.5 million acres of subsurface minerals were leased during a 2.5-year time period. This shale-gas play is transitioning from an early period of leasing and testing to a more deliberate focus and refinement on well-completion techniques and production of natural gas. A sharp increase in Fayetteville well production is a direct result of a multi-billion dollar financial investment by energy companies and has helped Arkansas to offset declining gas production from conventional wells. An estimated 500 wells are scheduled to be drilled in the Fayetteville Shale during 2007, and a new natural gas transmission line is planned to facilitate development of the resource.

Organic-geochemical and thermal-maturity data from Fayetteville Shale well cuttings indicate the formation is thermally mature and is restricted to dry gas resources. A highly organic-rich facies within the Fayetteville Shale is the stratigraphic interval that currently produces natural gas from wells in north-central Arkansas and is characterized by very high radioactivity and resistivity log signatures, which differentiate it easily from the overlying upper Fayetteville Shale and from the underlying Batesville Sandstone, Moorefield Shale, and Boone Formations. Ongoing research by the Arkansas Geological Commission is focused on reservoir characterization, analysis of produced gases, and outcrop to basin modeling of the Fayetteville Shale Formation.