The Mississippian limestone or Mississippi Lime play started around 2009 with the first horizontal wells in Oklahoma with SandRidge Energy leading the way. Three years later, companies like Devon, High Mount, and Calyx are opening up a horizontal Woodford play in the same area.

However, what makes the Mississipian limestone play somewhat unique – and attractive – is that it is very low-tech. At the same time, it is very cost-effective to drill into the formation with well costs ranging around US $2.8 million to $3.5 million.

"The Mississippian Lime is a fairly low-tech play, and you're in an area where there is already a lot of infrastructure in place from previous production," said Steve Antry, chairman and CEO, Eagle Energy Co. of Oklahoma.

"It is a relatively shallow play at 909 m to 1,818 m (3,000 ft to 6,000 ft) of depth. It costs about $3.5 million in well costs. There are a short number of drilling days. It is very low-pressure and we use low-tech equipment," he said.

"We're drilling our 50th well right now. We've been continuously surprised at the number of really big wells. Two years ago, the Mississippian was barely a blip on the radar screen. What's developing in this trend as it gets bigger is a series of core areas that keep elongating the play," Antry explained.

The horizontal wells drilled in the play have lateral lengths between 758 m to 1,515 m (2,500 ft to 5,000 ft) and are fracture stimulated in six to12 stages. The fracture stimulation treatments are not as large as those in the Bakken play or other unconventional resource plays such as the Eagle Ford, according to Magnolia Petroleum Plc.

landscape of a rig near Alva, Oklahoma

ABOVE: A rig drills for oil near Alva, Okla. (Images courtesy of SandRidge Energy)

SandRidge: 'Probably the biggest single player'

"The Mississippian play from our perspective has a lot better porosity than what you find with most of the tighter rocks that the industry is drilling today," said Kevin White, senior vice president, business development, SandRidge Energy. "In conjunction with better rock quality than tighter shales, it is rather inexpensive to drill.

"The formation is somewhere between 1,212 m to 1,818 m (4,000 ft to 6,000 ft), depending on what part of the play you're in, before you kick off and go horizontal. We spend around $3 million to drill these wells," he added.

And SandRidge knows what they