The recent idling of two refineries in southeastern Pennsylvania and plans to idle a third in the region by mid-2012 could nullify declines in U.S. gasoline imports, according to This Week in Petroleum published Jan. 19 by the Energy Information Administration.

With the closures of ConocoPhillips’ Trainer and Sunoco’s Marcus Hook refineries, East Coast refining capacity dropped 27% since the end of September 2011. Sunoco has said that it will shut its Philadelphia refinery by mid-2012 in the absence of a buyer.

At 18.9 million bpd in 2011, total petroleum deliveries, a measure of demand, fell 1.2% from 2010—marking the second largest drop in annual domestic deliveries in the last decade, the American Petroleum Institute reported Friday (1/20) in its latest Monthly Statistical Report, with the greatest annual decline occurring in 2008.

The data showed December 2011 petroleum deliveries dropped 5.9% from the year prior, falling to the lowest level in 15 years at an average 18.6 million bpd.

Global oil demand in the fourth quarter 2011 fell 300,000 bpd amid weakening economies, said the International Energy Agency in its Oil Market Report for January released Jan. 18, prompting the Paris-based agency to revise lower its projection rate for world oil consumption this year.

“Clear signs of economic weakness tipped global oil demand into a declining year-on-year trend at the end of 2011,” said IEA, saying the decline in fourth quarter global consumption was “its first such drop since the tail-end of the credit crunch.”