The Mississippian Limestone formation, a thick, porous carbonate ‘play’ that extends over millions of acres in northern Oklahoma and southern Kansas, was formed more than 300 million years ago when what is now North America was covered by a shallow ocean. The Mississippian Limestone play (MLP) is about 5,000 feet below the surface of the earth, and runs between 300 and 500 feet thick. It has been a drilling site for vertical wells for more than 50 years, and many considered the area to be “tapped out.”
But industry insiders now consider the Mississippian to be one of the most high-profile shale plays to emerge in recent years, thanks to horizontal drilling and multistate completions, technologies that are lowering development costs and raising recovery expectations through the roof. The challenge to tapping the oil in the Mississippian has always been that the ancient seawater is still trapped in the layer of rock with the hydrocarbons. Horizontal drilling (see video below) cuts through the oil-bearing rock, draining large amounts of the salt water efficiently.
The Mississippian Limestone play is yielding high-grade crude oil and attracting the attention of many companies that are buying up lease land and preparing to harvest the vast hydrocarbon deposits that the formation is thought to hold. High oil prices, relatively low development costs, proven history of production from vertical wells, and long-term potential make the Mississippian play a tremendous growth opportunity for the industry.