Investigators stand by as machines remove debris from the burned remains of a house on the 6300 Block of Twilight Avenue in Firestone, April 18, 2017.

courtesy of Matthew Jonas/Times-Call

Anadarko Petroleum said Tuesday it has reactivated more than 1,350 wells in northern Colorado that it shut down as a precaution last year after a fatal house explosion blamed on gas from a severed pipeline. The company inspected and tested pipelines connected to the wells before returning them to service.​

The company shut down hundreds of wells after an April 2017 explosion killed two people in Firestone, about 30 miles north of Denver. Investigators said the explosion was caused by odorless, unrefined natural gas from a severed pipeline that was believed to be abandoned but was still connected to one of Anadarko's operating wells.

Recent CPR News Firestone reporting:

  • A Year After The Deadly Blast, What The Neigbhors Are SayingEver since a home in Firestone exploded and killed two men last April, the state’s energy industry and its regulators negotiated and then publicly supported new safety rules for oil and gas wells in residential areas. As they’ve done that, some in the neighborhood still have questions about safety and property values, while others have moved on.
  • Deadly Well Didn’t Produce Much. Why Turn It On? A 25-year-old Anadarko Petroleum oil and gas well and flowline caused a deadly explosion last April in Firestone, after it had been shut down for a year. Investigators at the time found that a 1-inch flowline that carried gas from the well was severed at some point as the development of homes in Firestone moved closer to the well. But the flowline had not been disconnected from the wellhead and capped.

Anadarko permanently shut down and plugged 600 wells after the explosion. About 1,050 more remain shut down while the company decides what to do with them, Anadarko said.

The company did not immediately say how much oil and gas or revenue it was losing while the wells are idle.

Anadarko said three wells in the neighborhood where the house exploded remain turned off and will eventually be plugged and permanently shut down. That can't happen until litigation surrounding the explosion is settled, the company said.

Anadarko said it bought a house beside the explosion site in a settlement with the owner. The house was damaged by the blast.

The pipe blamed for the explosion was a flow line, a type that carries oil and gas from wells to nearby equipment. Colorado has hundreds of thousands of flow lines.

After the explosion, Colorado regulators adopted new rules for installing, testing and shutting down flow lines. They also require energy companies to report the locations of many pipelines to regulators.