The U.S. Geological Survey will reassess the Williston Basin at the request of North Dakota Senator John Hoeven (R-ND), who has asked the agency to study the potential of the Tyler Formation, a recent area of activity by companies such as Marathon Oil Corp.

Before 2013, the Three Forks Formation in the basin was generally thought to be unproductive.

Then the USGS released its 2013 assessment, upping its Three Forks estimates from essentially nothing to 3.73 billion barrels (Bbbl) of oil.

Now, the basin is up for a new physical after Hoeven pressed USGS director Suzette M. Kimball in late October to update the 2013 assessment.

Hoeven said industry advancements in directional drilling and hydraulic fracturing have greatly expanded access to resources in the Williston.

But his request also was driven by the industry’s work in the Tyler.

“They’re just developing the Tyler Formation. It is a newer development and [the assessment] will provide us more information,” he told Hart Energy.

The Tyler has produced more than 84 million barrels (MMbbl) of oil from 285 wells, peaking with daily production of 3.3 MMbbl in 1976. However, it has been relatively unexplored by horizontal drilling.

North Dakota officials said that Marathon Oil drilled four Tyler wells in Slope County in 2014. Two were plugged and abandoned, one was dry and the last permit was canceled.

While the Tyler may be an economical play at $100 oil rather than at today’s prices, any additional information the USGS can provide through an assessment would be beneficial, state officials said.

Hoeven said a new assessment could again show a significant increase in resources. “I think that’s good from a long-term standpoint, as far as not only attracting investment to continue to produce oil and gas in the Williston Basin.

“It’s also important for us as we continue to work to make sure we have the infrastructure and other amenities to maintain good quality of life.”

The Tyler has been a beguiling play, with a range of operators testing it. Most recently they have targeted Slope County, North Dakota.

Marathon Oil, which has drilled in the Tyler for several years, completed the Powell 31-27th in January of this year. Production was 18 bbl/d of oil and 45 bbl/d of water that month, according to the North Dakota Industrial Commission.

In 2013, when most attention was focused on the Bakken and Three Forks, North Dakota Geological Survey (NDGS) geologist Stephan H. Nordeng told Hart Energy that the formation is an extensive, organic-rich Pennsylvanian unit ranging from 286 million to 325 million years old.

“It contains organic-rich intervals consisting of kerogen in excellent quality, oil-prone source rocks,” Nordeng said.

“The success of Upton Resources’ [another operator at work in the play] horizontal Tyler wells appears to be a function of how consistently the horizontal laterals were able to stay within the targeted sandstone interval,” the NDGS said.

The USGS’ most recent estimates for the Bakken and Three Forks changed investors’ perception of the Williston Basin and doubled its resources. Hoeven was also behind the push for that assessment. He believes that in time, the Tyler could have the same effect on investment as the Bakken and Three Forks.

In a September 2014 presentation, Lynn Helms, director of the North Dakota Industrial Commission’s department of mineral resources, outlined job growth for the formation through 2050.

With the price of oil then relatively strong, Helms modeled production, gathering, fracking and drilling jobs. His presentation shows they would routinely top 1,500 by 2020.

Charts showed that rigs and wells would also increase, with roughly seven operating by 2020.

After the 2013 USGS report, Hoeven said investment in infrastructure soared “directly related to transport of oil, but also roads and housing and retail establishments. It was very important.”

Facing lower energy prices today, North Dakota can catch up to growth and develop a strategy to further reduce costs, Hoeven said. “An update of the resource through USGS is part of that planning,” he added. “This is going to be a long-term play.”