Crude oil prices closed in on $93 per barrel Friday morning with prices propped up by closure of a critical supply line in the Midwest. TransCanada Corp. said it shut down the Keystone pipeline Thursday with expectations that it would take three days to check out problems revealed during routine tests, MarketWatch reported. In New York, November delivery of West Texas Intermediate crude oil added 79 cents overnight to $92.89 per barrel on the New York Mercantile Exchange. Natural gas prices added 2.9 cents to $3.614 per million British thermal units. Home heating oil gained 2.44 cents to $3.1913 per gallon. Reformulated blendstock gasoline gained 1.49 cents to $2.7418 per gallon. At the pump, the average price for a gallon of regular unleaded gasoline was $3.715 per gallon, down from Thursday\'s $3.737, AAA reported.