With crude at $66 and oil stocks making all time highs, you wouldn't think this story could be possible. Is supply and demand working? Wait till the Dems run with this one. LONDON, June 4 (Reuters) - Oil firms have booked space on tankers to store up to 19 million barrels of crude in the U.S. Gulf amid refinery outages and a lack of onshore storage capacity, shipping industry sources said on Monday. "There are a number of factors playing into this but in the main we have onshore storage capacity issues and the contango in U.S. crude markets is able to pay nicely for it," one source said, referring to higher forward prices in the futures market. Firms were paying $50,000 to $60,000 a day to store the oil Analysts at Simpson, Spence & Young (SSY) in London said the lack of storage space had been caused by a spate of U.S. refinery glitches either "through planned maintenance or unexpected outages" which had seen less crude being processed. "Refineries have struggled to process the crude quickly enough and refinery utilization rates have only just moved above 90 percent," said SSY's Claire Grierson. "In addition, crude imports have been rising rapidly since March and there has been a greater crude flow from Canada into the US mid-West, which has caused a large crude build and squeezed onshore storage capacity," she said.