Production in North Dakota’s robust Bakken/Three Forks shale plays continues to ramp up, while prices for the state’s sweet, light crude oil have fallen 18% since June, prompting the chief oil/natural gas regulator to predict a Bakken benchmark price will evolve in time for the state’s 2015-17 budgeting cycle.

While the lower prices put more pressure on producers around the fringes of the Williston Basin, current prices “line up well with those of Cushing [OK] and elsewhere,” said Lynn Helms, director of North Dakota’s Department of Mineral Resources, during a webcast Friday.

“This should support the industry’s ongoing efforts to have a Bakken benchmark price [recognized throughout the industry],” Helms said.

Bakken crude oil on average fetched $90/bbl in June, and that dropped to $86.20/bbl in July, only to drop further in August to $78.46/bbl. Helms is projecting a price of $80-$85/bbl for the state’s use in estimating future oil/gas revenues in the 2015-17 budget period.

“We’re becoming detached from global oil prices,” said Helms, noting that the Brent price for European oil was developed when the North Sea was booming, but production there is now on a fairly steep decline. “The price softening is driving more barrels onto rail transport.”

Separately on Friday, North Dakota Pipeline Authority Director Justin Kringstad said rail moved 60% of Bakken crude in July, with the other 40% traveling in pipelines.

Historically a narrowing of the WTI and Brent oil prices sends more oil to pipeline transportation, but that hasn’t happened recently, and Kringstad intends to analyze that situation in the next few months.

In July, the WTI-Brent spread dropped below $5/bbl, Kringstad said, but for the month rail volumes stayed at slightly more than 700,000 b/d.