As Canada is officially bilingual, oil patch language and corresponding regulations can appear the same, with two ways to describe the same thing. June’s Insight explores some of this language across jurisdictions in which we operate.
In Western Canada, most of us are familiar with the abandonment vernacular like groundwater protection, bridge plugs, cement caps, surface casing vent flow, commingled abandonments, and gas migration. But there are some subtle differences. British Columbia refers to usable water, Alberta has the base of groundwater protection, Saskatchewan references fresh water-bearing formations, Manitoba simply denotes aquifers, while Ontario refers to the base of the deepest potable water zone.
Other Canadian differences exist for area-specific challenges. Cement plugs inside the production casing are required to isolate known problem zones or active and potential thermal formations that impact the production casing cement sheath integrity. Thermal cement is common to better withstand the degradation of higher temperatures while the Prairie Evaporite formation in Saskatchewan needs an adjacent brine saturated cement plug.
Abandoning former oil and gas producing zones is mainly conducted using bridge plugs but the nuances remain. Manitoba requires an additional mechanical plug to be set 5 m below the surface casing setting depth with an 8 m cement plug on top. Ontario has similar requirements. New Brunswick and British Columbia lean on Alberta Directive 20 guidance.
In Ontario, well abandonments are referred to as “plugging” (also common in the United States). There is arguably a good requirement to set a cement plug inside the production casing across any multi-stage cementing tools. Cement plugs are also required across the base of the deepest potable water zone.
While inactive well management is on-going in Western Canada, it is interesting to observe what our neighbours to the south are doing. North Dakota has rigorous criteria on suspended wells. After one year of inactivity, operators are placed on notice to reactivate or abandon the well within six months. Operators who do not comply can have their equipment confiscated, the well abandoned and reimbursement sought from the operator and any working interest holders. The Texas Railroad Commission, whose mandate includes oil and gas wells, has similar inactive well abandonment requirements.
Finally, on the surface abandonment side, generally referred to as the “cut and cap”, Manitoba mandates a steel plate to completely close off the end of the surface and production casings. Manitoba requires when a well has been abandoned the related flow line (pipeline) shall be abandoned as well. While Alberta has switched to vented well caps, routine Saskatchewan abandonments can also use vented caps but non-routine abandonments cannot. Saskatchewan wells abandoned within 2 km of an urban municipality must use vented caps, except where the well is located within a water body. North Dakota uses the welded steel plate method for cut and caps.
The simple message for all projects and collaboration, make sure you know the language!
Best,
-Sabrina
About the Author
Sabrina Moore, P.Eng., Engineering Supervisor
Sabrina has experience in all facets of closure from downhole abandonment, pipeline and facility decommissioning to environmental site assessments. This holistic approach has developed an adaptable skillset to all types of closure projects. Within the abandonment group, she focuses her experience on both routine and non-routine well abandonments. Sabrina is involved with industry groups such as the Well Abandonment and Integrity Society and is a professional engineer in good standing with APEGA.
