APNewsBreak: Texas firm temporarily plugs leaking oil well in western North Dakota

Texas firm temporarily plugs leaking ND oil well

BISMARCK, N.D. — A ruptured oil well in western North Dakota was temporarily plugged on Friday after leaking more than 2,400 barrels of crude and water, company officials said.

Bob Cornelius, a spokesman for Denbury Onshore LLC of Plano, Texas, said the company had done a successful static kill by pumping heavy mud in the well that began leaking early Wednesday morning about 2 1/2 miles southwest of Killdeer.

Crews began pumping the mud into the well immediately after the spill was detected, and it stopped leaking at about 1 a.m. on Friday, he said.

“The well is in static condition — it is no longer leaking,” Cornelius said Friday.

Concrete plugs were being installed on Friday at some 9,000 feet below the well and at the surface to allow for pressure readings in an attempt to determine why the wellbore failed. Depending on the severity of the failure, the well may be permanently plugged with concrete or repaired and reused, Cornelius said.

“We need to figure out what happened first,” he said.

Randy Robichaux, the company’s health, safety, and environmental manager, said 2,200 barrels of water used in drilling operations and 246 barrels of oil had been recovered by Friday morning.

Denbury Onshore, a subsidiary of Denbury Resources Inc., operates 185 wells in North Dakota, including 64 horizontal wells that target the rich Bakken shale and Three Forks-Sanish oil reservoirs in the western part of the state, Cornelius said.

The ruptured well, dubbed Franchuk 44-20 by the company, used horizontal drilling and hydraulic fracturing, a process that uses pressurized fluid and sand to break open oil-bearing rock some two miles underground.

Advance horizontal drilling techniques and hydraulic fracturing have been used in North Dakota for less than a decade. Lynn Helms, director of the state Department of Mineral Resource, said it was the worst spill in state history from a horizontal well.

Helms said an inspection found that the company used 10 chemicals in its hydraulic fracturing fluid, though none were toxic at diluted levels in the well.

Robichaux said all fluid and oil that leaked from the surface has been captured. One monitoring well was drilled on Thursday to test groundwater near the well. Two other monitoring wells were slated for drilling on Friday, he said.

A protective dike was constructed Wednesday to prevent oil from reaching a nearby creek.

“We have contained everything at the surface and there is no threat to any water supply,” Robichaux said. “We don’t have any signs that groundwater has been impacted and we are monitoring for that.”