A damaged turbine in the main Alberta natural gas pipeline system, which substantially curtailed shipments, was scheduled to be repaired last week.
Nova Corp., Calgary, said the damaged unit reduced volumes to export pipeline connections from Alberta by 225 MMcfd. Some producers estimated the delivery curtailment was much higher.
Repairs to the 25,000 kw turbine at Schrader Creek, 100 miles northwest of Calgary, began Aug. 18. Nova said the damage occurred when a part broke and hit turbine blades, damaging moving and stationary parts of the turbine.
The Nova system delivers gas to pipelines operated by TransCanada PipeLines Ltd. and Foothills Pipelines Ltd., which carry gas to markets in eastern Canada and the U.S.
David Cornies, Nova manager of gas supply and control, said the accident caused one of the most severe curtailments in terms of total interruption the company has had in his memory.
Nova said it could not meet producer requests to issue a force majeure statement because that can be declared due only to an act of God. The company was issuing a curtailment notice.
Stan Wong of North Canadian Marketing Inc., Calgary, said the incident raised questions in the minds of some customers about the reliability of Alberta gas supplies. He said the turbine shutdown could cost producers $4-5 million/day.
Some gas marketers, such as Progas Ltd., Calgary, halted spot market sales in order to meet demands of noninterruptible contracts.
Progas said customers in New England and the U.S. Midwest increased their orders because of concerns about the effect of Hurricane Andrew on Gulf Coast supplies.
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