SHELL CANADA SCHEDULES ANNUAL REFINERY SHUTDOWN Shell Canada Ltd, 72 pct owned by Royal Dutch/Shell Group <RD> <ST>, scheduled its annual maintenance refinery shutdowns during the next two months, company spokeswoman Judy Wish said. Wish said refineries will stockpile production before the shutdowns to maintain normal supply while maintenance is carried out. Production at Shell's major refinery at Strathcona Alberta, will be closed for about one month, Wish said. There will be no layoffs associated with the refinery maintenance, she added.