(Reuters) - A North Dakota oil well owned by Exxon Mobil subsidiary XTO Energy blew out on Saturday, leaking more than 550 barrels (23,100 gallons) of crude, some of which left the wellpad and seeped into surrounding grasses.
The well, located in a rural area 25 miles southeast of Watford City, was being hydraulic fractured when its pressure control valves failed and it leaked the oil and about 110 barrels (4,620) of saltwater, according to state and company officials.
The well was brought under control on Sunday morning. No one was injured.
"We are working to understand the cause," XTO spokeswoman Suann Guthrie said on Monday. "We are very sorry this incident has occurred."
The company's emergency response responded to the leak, and local officials were notified. XTO said it has begun cleanup at the site.
The well, Deep Creek Federal 43X-5D, is located on the same drilling pad as four other wells and was first drilled on April 25, according to state data.
(Reporting by Ernest Scheyder; Editing by Leslie Adler)