A typical orphan well you might see is on forested or agricultural land, away from sensitive ecosystems.
Having usually been drilled within the last 40 years, the location is well-documented with an existing access road. Surface concerns around wildlife, livestock, and vegetation and sediment control are very often familiar and predictable.
The West Castle wells, located in the southwest corner of the province, were anything but typical. Drilled between 1907 and 1910 by the Canada West Oil Company of Victoria B.C., they represent some of the oldest wells in Alberta and far predate the stoppage in 2015 of any new industrial leases in Castle Wildland Provincial Park.
In fact, the two West Castle wells predate reliable recordkeeping and first came to the attention of regulators when reported by a local recreational trail user. This was the catalyst for a unique collaboration among conservation advocates, provincial and federal environmental experts, industry regulators and the OWA.
“The early involvement of so many interested stakeholders put a different lens on the work,” says Dave Marks, who manages land and stakeholder relations for the OWA. “We started from a point of ‘join us and let’s collaborate and do this right’ before we even got into the regulatory process.”
A working committee was assembled involving representation from the Alberta Energy Regulator, Alberta Environment and Protected Areas (EPA); Fisheries and Oceans Canada; Castle-Crown Wilderness Coalition; the OWA; and our prime contractor, Vertex Resource Group. Collaboration was constant.
“Everyone was fully invested in getting it right,” says Wonnita Andrus, a land-use planning ecologist with EPA. “It was a great experience to see everyone care so much about this beautiful and sensitive space.”
There were many considerations around this sensitive local habitat. It supports a vast array of wildlife, as well as being part of the critical watershed for downstream communities. Of particular concern was the spawning grounds for Bull and Westslope Cutthroat Trout, two “Species at Risk” and in a federally designated “Critical Habitat”.
The timing of the work was important. Fisheries regulation meant that the most intense work needed to be completed in a short window between restricted spawning periods. And, the entire project had to be completed within a space of two months before expected heavy snows, for which the Castle area is famous.
“Everybody was able to come together with their best recommendations—when work could and couldn’t be done and ensuring appropriate placement of equipment and structures,” says Wonnita.
The first step in an area accessible only by a footbridge and trails was to create access for machinery in early August 2022.
“When these wells were drilled, they would have brought in a rig with horses,” says Brad Malley, OWA Director of Operations. “That wasn’t an option for modern equipment and would have been a major disturbance to the river.”
The solution was to move the footbridge and place two temporary bridges, with the first spanning more than 25 metres. The bridges needed to be placed carefully to minimize disturbance to the riverbank and be set well back from trout spawning areas surveyed by EPA and Fisheries and Oceans Canada. A counterweighted design was used to lower each bridge into place so that supports weren’t required in the river or near the banks.
Once the site was accessible, nearly 800 interlocking wood mats were laid down to protect the surface soils and vegetation so that work could begin. Subsurface water leaks from the well furthest from the river underlined the importance of getting the decommissioning done as soon as possible, while extra care and containment was needed for the well closest to the river, which was just one metre from the bank. In fact, Brad notes that tangled driftwood and debris indicate that at some point, the well was in the river.
With emergency spill response equipment on standby at the site, wellheads were installed on both wellbores and monitored for several days by the OWA team to better understand the characteristics of each well prior to decommissioning.
After cutting the well nearest the river below the surface, a special cap was installed in case of flooding. After the wells were decommissioned, the crew backed out of the site. Mats were removed allowing vegetation to spring back, temporary bridges were lifted from the banks and the footbridge was returned to its place. As an added benefit, the recreational access road was greatly improved with redistribution of materials from the project. Under the watchful guidance of the working committee, the land was opened again for recreational use by the end of September.
Wonnita and Dave agree: “This was a model” for decommissioning projects in sensitive environments.