A forest and grass fire, spreading rapidly out of the Rocky Mountains and onto the plains in southwestern Alberta, has prompted safety shut-ins of wells producing sour natural gas laced with hydrogen sulphide.
Shell Canada Ltd., Questfire Energy and West Lake Energy temporarily closed more than two dozen sour gas wells and associated production facilities as a safety precaution, according to the Alberta Energy Regulator.
The emergency action only affected a minority of production in the area. Operations continued at the main regional gas operation, Shell’s 180 MMcf/d Waterton processing plant. The fire’s effect on the province’s total gas production of about 11 Bcf/d is considered marginal.
The industry interruption is considered modest compared to destruction of natural attractions, the abrupt end to the tourism season, traffic disruption by road closures and damage to ranches and farms in Waterton National Park and neighboring rural communities.
Wells and production sites in the Waterton region have fire resistance features including large gravel surfaces. Destruction centered on wooden fences, corrals and buildings in the path of the blaze, including the park visitor center. The national park, neighboring agricultural areas and a nearby native reserve were evacuated.
The Kenow Fire, named after its ignition area west of the Continental Divide, covered about 44,000 hectares (176 square miles) as of Wednesday morning and continued to spread on plains that a hot summer has left tinder-dry.
The advancing fire front, blown by strong wind coming out of the southwest, was moving in a northeasterly direction away from the Waterton plant and surrounding wells. Firefighters expected natural help as a cold front arrived, bringing rain showers and lowering the temperature.
The dangerous hydrogen-sulphide impurity, which occurs in nearly one-third of Alberta gas deposits, has repeatedly aroused public resistance and inspired ever-tighter safety and environmental regulation. Industry has adapted, sustained and at times expanded production in the Waterton region for 60 years.