90-year-old oil well near Turner Valley, Alta., being decommissioned

The Orphan Well Association has been monitoring three different oil wells in Alberta, including one on the northwestern edge of Turner Valley, Alta. (File)

Work crews preparing to work on an old Alberta oil well to clean up an issue that was discovered after the equipment was originally decommissioned 25 years ago.

The Orphan Well Association (OWA), which has been managing the Katana Resources British Dominion Well #3 since 1997, is scheduled to begin work in a few weeks at the site located on the northwestern edge of Turner Valley.

The well was shut down in 1996, OWA says, but trace amounts of methane were found at the site after that work was completed.

While it was expected to send crews to the site earlier this year, it chose to delay operations until now.

"The decommissioning activities will now take place between Nov. 1, 2022, and March 31, 2023," the OWA said on its website.

"Two factors contributed to this decision. The first is that the OWA wants to minimize disruption to the site. Delaying until the ground is frozen will result in the least impact to the field."

The OWA also says a service rig would not be able to successfully complete the work and it lacked an appropriate drilling rig. It said waiting until one was available would "help ensure the decommissioning activities go smoothly."

Despite the issue, it says the well is not a risk to the public or the environment.

The OWA has also completed work on two other projects in Alberta, including the decommissioning of two historic wells located within Castle Wildland Provincial Park.

At that location, crews decommissioned two wells that were drilled by the Canada West Oil Company between 1907 and 1910.

It says both were "never properly decommissioned," so the OWA stepped in with a project that involved the removal of existing bridges, installation of temporary bridges and sophisticated measures to protect sensitive vegetation.

The Castle River project was completed at the end of September.

The OWA says it also installed an active methane management system at a playground in Vermilion, Alta., this past spring.

The equipment was placed there to monitor methane from the Tenwell #1 well in the town's Brennan subdivision.

Turner Valley is located approximately 65 kilometres south of Calgary.