US-based Whiting Petroleum has agreed a deal to sell its assets in the Fort Berthold Indian Reservation area to Calgary-based Rimrock Oil & Gas for $500 million.

The assets, located in Dunn and McLean counties in North Dakota, comprise 29,637 net acres, 29 non-operated drilling spacing units and 17 operated.

Net daily production averaged 7785 barrels of oil equivalent per day in the second quarter.