Michigan's Antrim Shale

August 20, 2010

Located in the Michigan Basin, Antrim Shale is a late Devonian age formation that spills over into Indiana and Ohio. Originally named St. Cleric, Antrim contains mostly organic-rich upper and lower black shale with middle gray shale or limestone.

Antrim's first production hit in 1940, but it wasn't until the 1980s when the play took off. The majority of the action occurs over approximately 39,000 square miles in Antrim, Crawford, Kalkaska, Missaukee, Montmorency, Oscoda and Otsego Counties.

Antrim produces over 30 million cubic feet of natural gas per day in over 9,700 active natural gas wells. Antrim Shale has over 95 percent drill success and a reserve life of at least 20 years.

Antrim is shallower than many of the shale plays. Some areas have gas just 200 feet below the surface while deeper spots go below the surface by 2,000 to 2,500 feet. Because of the shallowness of the play, residents have voiced concerns about hydraulic fracturing and its effects on the water supply and environment.

Companies in Antrim Shale

LINN Energy, LLC purchased acreage from HighMount Exploration & Production LLC in the northern Michigan part of Antrim Shale. LINN believes the $330 million deal will pay off due to low-risk drilling and optimization opportunities. The company also does horizontal drilling in Granite Wash in the Texas Panhandle and works on oil-related projects in Permian Basin. LINN has plans in the works to acquire properties in East Texas Oil Field in Gregg and Rusk Counties.

Antrim is one of Atlas Energy's key shale plays with 2,400 wells in production and 700 more planned. In addition, Atlas' also does a lot of work in Marcellus Shale, Indiana's New Albany Shale and Tennessee's Chattanooga Shale. With over 57 million cubic feet equivalent per day in production, Atlas is the largest oil and gas producer in Michigan. The company's assets include 270,000 net developed acres and 30,000 net undeveloped acres.

Antrim is also the home of the majority of BreitBurn Energy Partners' Michigan acreage. The company has 90 productive wells in Antrim since 2008.