Image courtesy of Whiting Petroleum

Crews have been working since Thursday to regain control of an oil well after a blowout caused 15 workers to run for safety.

The blowout occurred  four miles south of Watford City, North Dakota at a well about seven miles north of the Theodore Roosevelt National Park North Unit, according to Lynn Helms of the state’s Department of Mineral Resources.

No injuries were reported.

Whiting Oil and Gas is the operator.

The well was flowing at about 200 barrels per hour after the blowout but fluids were being tanked on the site,  according to Whiting spokesperson Jack Ekstrom.

Hydraulic fracturing had been completed on the well.

A leak in the seal of the blowout preventer caused the incident, Ekstrom said.

A state official said the well has a three-part blowout preventer but the lower portion failed.

A mist of oil and water fell around the site.

A clean-up will be needed in a radius of a quarter-mile around the site, the official said.

Crews from Wild Well Control arrived after the blow out, Whiting said.

“The 15 workers who ran away from the well left their pickups at the site, said McKenzie County Emergency Manager Jerry Samuelson,” according to a report by the Forum of Fargo-Moorhead.

Samuelson directed a school bus that was in the area to pick up the workers.

“When that thing blows, you just never know,” Samuelson told the Forum. “There’s a possibility of explosion.”

In 2012, a worker died when he was hit by pickup during the chaos after a blowout in Williams County, the report said.