Oil output in North Dakota, the third-largest producing state in the U.S., is estimated to have fallen by around 500,000 barrels through October, after wildfires crossed into key producing counties earlier this month, a state regulator said on Thursday.

Exxon Mobil XOM.N was among operators that last week shut in some oil wells and production sites in the state in response to the fires.

“My best estimate is around 500,000 total barrels removed from those October numbers,” said Justin Kringstad, director of the North Dakota Pipeline Authority.

There were around 100,000 barrels per day (bpd) affected in the immediate response to the fires, down to around 50-80,000 bpd in the week after, Kringstad added.

The state currently has 18 frac crews operating, down from 20 last month, according to Mark Bohrer, assistant director of the oil and gas division at the North Dakota Department of Mineral Resources.

“We have 40 rigs running today even with the mergers and acquisitions, our rig count has remained fairly steady,” Bohrer added.

Oil production in the state rose by 9,630 barrels per day (bpd) in August, to an estimated 1.179 million bpd, according to state regulators on Thursday.

And the number of producing wells in North Dakota in August reached a record high, at 19,117 wells.

The state has also permitted three to four four-mile lateral wells, which will help operators develop some of the tier two and three locations that were previously economically more challenging to drill, according to Bohrer.
Source: Reuters (Reporting by Georgina McCartney in Houston)