Determined operators are slowly chipping away at a tough shale play that could add another layer of production to the Black Warrior Basin's unconventional resource mix. The Upper Mississippian Floyd and Neal shales are two names for a formation that occurs in northwestern Alabama and northeastern Mississippi. Floyd is used in Alabama, and includes the Lewis sandstone; in Mississippi, the black shale between the Carter and Lewis sandstones is the Neal. Whatever the term, the Mississippian-aged rock is correlative to the Arkoma Basin's Fayetteville shale and the Fort Worth Basin's legendary Barnett. The Black Warrior version of the shale is geologically complex. In the basin's northern portion, two dense limestone units sandwich the Floyd. Here, the shale attains more than 200 feet in thickness, contains more than 3% total organic carbon (TOC), and is thermally immature, according to work done by Matthew Totten and Albert Oko at Kansas State University. In the basin depths, the shale has similar TOC values but is 100 feet thicker and thermally mature. This slice of the play lacks the overlying limestone unit. Early movers in the Floyd included Murphy Oil, Noble Energy and Wagner & Brown Ltd., and work centered in Pickens County, Alabama. In 2005 and early 2006, Murphy (reportedly partnered with Noble) drilled a handful of exploration wells in southeastern Pickens to depths around 7,500 feet. Results were uneven and no well was put on production. For more on this, see the September issue of Oil and Gas Investor. For a subscription, call 713-260-6441.