Oil prices dipped on Wednesday, reversing early gains, as weak economic data from China weighed on commodities and added to the woes of an oversupplied market that has seen prices more than halve since June 2014. Crude edged up in early Asian trading after industry group the American Petroleum Institute reported that U.S. crude stockpiles fell 3.7 million barrels last week, with stocks at the Cushing, Oklahoma, delivery point for U.S. crude futures alone down almost 500,000 barrels.