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Published September 30, 2013, 11:19 AM

Marthon exploring the Tyler Formation in western ND

DICKINSON, N.D. -- Marathon Oil is the first company to try modern horizontal fracking in the Tyler Formation after spudding a well in northeastern Slope County this month.

By: Katherine Lymn, Forum News Service

DICKINSON, N.D. -- Marathon Oil is the first company to try modern horizontal fracking in the Tyler Formation after spudding a well in northeastern Slope County this month.

If successful, Marathon could be the first of many companies to drill that way in the Tyler, a geologically complex formation beneath the southwest part of the state that is viewed by many as the Bakken’s little brother. The formation has produced oil from vertical drilling in the past, but most of the oil that can be caught that way has been tapped by now.

Though it doesn’t have all the potential of the Bakken, the Tyler is similar geologically, which allows Marathon to use Bakken techniques there. The company plans to target the limestone layer between two organic-rich shales, Department of Mineral Resources Director Lynn Helms said.

Marathon is approved to drill a total of four wells in a part of the Tyler containing organic-rich limestone layers that average 5.5 percent total organic carbon (TOC), said state subsurface geologist Timothy Nesheim.

“Organic-rich rock intervals generate oil and gas, and rocks with greater than 4 percent TOC are typically considered excellent quality in the oil and gas industry,” he said.

The Tyler will vary across North Dakota more than the Bakken does, which means companies would likely have to use more diverse techniques to produce oil.

Marathon showed interest in the formation after Nesheim and colleague Stephan Nordeng began writing reports on the Tyler’s potential about three years ago, and Marathon hasn’t been the only company calling.

Continental Resources, Whiting Oil and Gas, XTO Energy Inc., Enerplus Resources and Williston Exploration have recently cut sample cores of the Tyler, Nesheim said.

Marathon estimates it’ll get about 1.6 million barrels of oil equivalent from the four wells. The company’s Bakken vice president Terry Kovacevich and spokesman John Porretto wouldn’t elaborate on its plans.

Since the late 1950s, when drilling began in North Dakota, vertical drilling has produced about 85 million barrels of oil from about 288 Tyler wells, Nesheim said.

So far, that drilling has targeted “localized sand bodies” ranging in size from a few square miles to 10 square miles, most of which have been discovered and developed.

As far as vertical drilling, “the Tyler kind of ran its course,” he said.

Marathon has also taken on the Tyler now because most of its Bakken wells are producing at this point, Helms said, “so they’re looking at new prospects.”

Area impact

If Marathon is successful, Helms said, cities like Amidon and New England could grow. He said development of the formation now is where the Bakken was in 2004.

“Probably most of the workers that would service the drilling rigs and that sort of thing would come out of Dickinson,” he said, “but if you look at the town of Dunn Center, there are new oil company offices there, there’s a revitalized downtown, there’s housing being developed for permanent employees to operate wells.”

Water is another story.

Rep. Mike Schatz, R-New England, said the area likely needs more water supply either way, especially if New England becomes a hub city for Tyler development.

But Southwest Water Authority CEO Mary Massad says it would be difficult to expand water infrastructure in such rural places.

“There are some areas especially in Hettinger and Slope County where we are kind of challenged, water-wise, and people are gonna have to look at alternatives” like well water or limited supply water storage, she said.

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