What is the Antrim Shale?
The Antrim shale lies in the Michigan Basin with principal development in Ostego and Montmorency Counties, Michigan and to
a lesser extent in Kalkaska, Crawford and Oscoda Counties, Michigan. While the bulk of the play lies in Michigan, the Antrim
Shale covers roughly 39,000 square miles and extends into ares of Ohio and Indiana, as well as Michigan. The Antrim
shale is a brownish-black shale that overlies the Traverse Formation. The shale mainly produces methane (CH4) with minor
amounts of CO2. Most drills in the Antrim shale require stimulation by hydraulic fracturing to attain commercial production
rates, however; natural fractures are still and important control on Antrim shale gas production. The U.S. Geological Survey's
National Assessment of U.S. Oil and Gas estimates that approximately 7 trillion cubic feet of gas (2005) are recoverable in
addition to discovered quantities from the Antrim shale.
The Antrim Shale is a shallow gas play. Two
other shale plays, the Utica Shale and the Collingwood Shale run beneath the Antrim Formation in Michigan and Ohio. While the Antrim play is mostly natural gas, there
has been some liquids and oil found.
- Antrim shale gas production began back in the 1940s in northern
Michigan where 8 gas wells were drilled in Otsego County, Michigan. However; it wasn't until the 1980s that the Antrim
shale gained its popularity for being a key drilling objective. New technologies during the late 1970's into the 1980's
made it possible for the Antrim shale to economically produce gas. To date, over 9,000 gas wells have been drilled throughout
the Antrim shale play with depths of the wells ranging mainly from 150 feet to 1500 feet, however; a few wells have been drilled
as deep as 2,200 feet. Wells drilled into the Antrim shale have proven to be relatively inexpensive, with an average cost
of approximately $350,000 in late 2008.
Antrim Shale 2013 - Due to low natural gas prices in
the U.S, the Antrim Shale will probably see little activity in 2013. Oil in the Antrim Shale has been mild so exporation
and production companies haven't shown a lot of interest. However, if natural gas prices rise up between 5-7 BCF you
will see a lot more drilling come back to the Antrim Shale. For now, keep track of comments given by the drilling companies
See Also - Collingwood Shale - Utica Shale