Chevron fined for leak after heavy rain
Chevron is paying a $30,000 fine in connection with a pipeline that broke during heavy rain last August, spilling about 1,220 gallons of oil and 9,600 gallons of produced water at its Rangely-area operations in Rio Blanco County.
The Colorado Oil and Gas Conservation Commission approved the fines under an agreement with Chevron to settle an enforcement action in the matter.
The leak involved a fiberglass flowline leading from a well.
“The issue at this well arose under unique circumstances in a unique (oil and gas) field,” David Beckstrom, a state oil and gas enforcement officer, told the commission before it approved the settlement at its meeting earlier this month.
He said some commission staff describe the Rangely oil and gas field that Chevron is working in as probably the most complex field in the state, and one of the more complex fields in the country.
It’s an older field, and Beckstrom said Chevron uses water and gas to control pressures in reservoirs to foster production, sometimes also incorporating carbon dioxide into that process.
As a result, Chevron operates about 400 miles of flowlines in the field to carry oil, gas, carbon dioxide, and water produced from hydrocarbon-bearing formations.
In Beckstrom’s words, “a significant rain event” struck the Rangely area on Aug. 8, 2016, resulting in what he believes was about 1.5 inches of moisture in 24 hours and causing the flowline to rupture. The storm was accompanied by lightning, which disabled a communications tower linking Chevron’s onsite monitoring systems with its main operations hub.
Beckstrom said Chevron has 43 siphons in the field that are intended to gather stormwater and any oil that spills.
On Aug. 8 all of them filled to capacity, triggering alarms, and leaving Chevron trying to figure out how to respond “to all the things happening in the field with imperfect information” because of the communication tower issues, he said.
He said workers ended up walking every flowline and visiting every siphon to inspect them, and it took them two days to discover the spill.
Chevron ended up determining that a failed check valve exacerbated the size of the spill. The enforcement agreement finds it in violation of rules related to that valve, including failing to keep it in good mechanical condition.
It’s estimated that the spilled fluids mixed with nearly 130,000 gallons of rainwater. Most of the fluids and accompanying rainwater were contained in a ditch and siphon. However, some soils in the area continue to have elevated salt levels. Chevron is washing the soil with water and is required under the agreement to finish the cleanup by Aug. 11.
Beckstrom said the state negotiated the agreement “in light of all the complicated factors” involved in the incident.
In March, an estimated 4,800 gallons of oil from a Chevron pipeline spilled into a dry drainage outside Rangely, traveling about two miles in vegetated terrain before being stopped by a siphon. Some birds and mice died as a result of the spill.
The Center for Western Priorities conservation group says Chevron last year reported the fourth-highest number of spills of any energy company in Colorado, with 31. Chevron has been spending millions of dollars over several years to upgrade its systems in the Rangely area, work that has involved removing at least 11 miles of pipes from service.