OKLAHOMA CITY—When Wade Hutchings, Marathon Oil’s regional vice president of Midcontinent assets, joined the Oklahoma division two years ago, he questioned his team, “Do we really know the edges of the viable Woodford formation in the Stack or the Scoop plays?

While certain edges have been defined for each of these two central Oklahoma oil and wet gas targets over the past several years, “I would contend there are areas where we still don’t know the viable Woodford play. Although we know where today’s sweet spot is, I remain confident we will continue to grow the size and scale of these plays.”

Hutchings addressed some 1,400 attendees at Hart Energy’s DUG Midcontinent conference in late February.

Active for more than 100 years in Oklahoma, the stacked nature of the Scoop and Stack plays is becoming an increasingly valuable forward driver for Marathon Oil’s operated and nonoperated positions, he said.

The company holds some 175,000 acres prospective for the Woodford Shale, its primary target, and at least 63% of those acres have a stacked unconventional target sitting above them. “The stacked nature of these plays will provide numerous advantages to future play development and competitiveness,” Hutchings said.

Most prominently, the Springer Shale is prospective in the Scoop region, and the Meramec Shale in the Stack.

“We remain optimistic that several of our newer plays, the Meramec Shale and the Springer Shale, are emerging as viable economic targets and will become a more important part of our unconventional production growth in the years to come.”

Structural complexities in the Scoop area can be considerable, Hutchings said, particularly in the northern portion of the Ardmore Basin that Marathon and others have recently targeted for Woodford production. A series of faults, sinklines and anticlines places the Woodford target at materially different depths and dips.

“Our ability to leverage 3-D seismic, the continued reprocessing of that seismic, and integrating it with other subsurface information, has been critical to successfully drill and complete the 12 wells in that area in the last year and a half,” Hutchings said.

All of the company-operated wells drilled in the northern Ardmore Basin part of Scoop were 5,000-foot laterals; six wells in the (southern) region ranged between 7,500 and 10,000 feet in length.

“Where feasible, we continue to see a material economic uplift with extended laterals in many of these plays we’re targeting in Oklahoma. We continue to drive higher per-well productivity in our operated Scoop wells,” a 46% return on 30-day IPs year over year through 2014. Thirty-day IPs averaged above 1,000 boe/d for 2014.

“We’re now ready to move into development phase in the Woodford Scoop, and begin to test additional layers with the drill bit,” said Hutchings.

The company has been analyzing the Springer Shale for two years and plans to drill up to two operated wells, its first, in 2015.

Moving north, the Stack region is starting to compete for capital in both drilling and leasing dollars as well, he said. “We continue to find ways to increase per-well productivity and to drill those wells cheaper and cheaper.”

Marathon made “material advances last year” in understanding the Meramec potential in its own wells, and in partner wells. “It’s critical to drive further capital efficiency. As we compare well-cost improvements across all the plays we track, we have a lot higher potential for further improvements in the Oklahoma basins than anywhere else in our company’s portfolio.”

Although the sweet spot today is in the rich-gas condensate window, he said, “I think we will find more and more of the Scoop and Stack plays that are viable than we think today.”