China is emerging as the winner from OPEC’s battle with rival oil producers as the world’s biggest energy consumer stockpiles crude. The nation’s efforts to boost reserves may increase its imports by as much as 700,000 barrels a day in 2015, according to London-based Energy Aspects Ltd. That’s more than half the global glut forecast by Citigroup Inc. after the Organization of Petroleum Exporting Countries refrained from cutting output at its meeting last week. Brent crude has slumped 41 percent from its peak in June. The dwindling number of investors still betting on a rebound in prices can at least count on Chinese demand. OPEC decided to maintain output targets even as a shale boom boosts U.S. production to the highest in more than three decades and causes a global supply glut. As crude extends its slump to the lowest level in more than four years, China is seeking to build a strategic petroleum reserve. “This is a golden time window to acquire more strategic oil stockpiles at lower costs,” Gordon Kwan, the Hong Kong-based head of regional oil and gas research at Nomura Holdings Inc., wrote in an e-mail Nov. 28. China will be “a big beneficiary” from the OPEC decision, he said.