Oil futures settled up slightly on Thursday, well off session highs, after a sharp but short-lived boost from a much bigger-than-expected decline in U.S. inventories of crude oil and gasoline. Oil has not sustained gains for more than a couple of weeks as investors have grown more worried about the stubborn global crude glut. U.S. crude stocks fell 6.3 million barrels, the U.S. Energy Information Administration (EIA) said, citing stronger refining activity and reduced imports. That was much more than the draw of about 2.3 million barrels analysts had forecast, and it took total crude inventories to 502.9 million barrels, the lowest since January. Crude prices gave back gains in the early afternoon. After hitting a high of $46.53 a barrel, U.S. futures settled up 39 cents to $45.52 a barrel. […]