Oil wells abound in North Dakota, and while some are having the usual spill issues, others are being discovered by accident.
A valve leak at a water injection well four miles northwest of Maxbass, ND, caused a spill of oil and saltwater, the North Dakota Department of Mineral Resources said Monday.
The initial report from company Denbury Onshore said 50 barrels of oil and 300 barrels of saltwater released Friday at the Fossum B3 water injection well in Bottineau County. All fluids ended up contained to the well site and recovered, the department said.
A water injection well is used for enhanced oil recovery and is not the same as a saltwater disposal well, the department said.
The Department of Mineral Resources Oil and Gas Division has a state inspector traveling to the site.
Meanwhile, cleanup is on tap at a former oil-well pad and reserve pit encountered while containing the Tesoro oil spill near Tioga earlier this fall, according to the North Dakota Health Department.
The old well site had been operated by Hess Corp. The company issued a statement saying it has been investigating since learning of the discovery of an abandoned well site. The company reported it is working closely with state officials to take appropriate action.
Kris Roberts, an environmental geologist with the North Dakota Health Department, said they found the well pad and reserve pit during the process of putting a containment wall around the oil spill. A pipeline rupture in September spilled more than 20,000 barrels of oil across several acres of farmland near Tioga.
Roberts said the removal of residual contaminants from the old well site will take place once Tesoro begins active soil remediation. The old reserve pit contains oil and oil-field debris commonly generated during petroleum activity in the 1950s and 1960s, he said. Environmental rules for closure of sites were less stringent at that time.
Roberts said there are more than 8,000 former well sites around western North Dakota. He said the health department orders cleanup if a dormant well rises to its attention, as happened when the oil spill near Tioga intersected with the old Hess site.