Investing.com - OPEC may end up doing away with production cuts sooner than expected due to a surge in global demand, according to analysts at Goldman Sachs (NYSE:GS).Despite the fact that major oil producers agreed just last November to extend their output curbs through the end of 2018, these experts predict that global stockpiles will continue to shrink through the second quarter of next year. According to their forecast, the market may well rebalance by mid-2018, spurring OPEC’s exit from the need to continue with production cuts through the end of the year.“Global inventories will have re-balanced by mid-2018, leading to a gradual exit from the cuts,” Goldman said in a recent note to clients.Despite these conclusions, Goldman left their forecast for Brent crude unchanged at $62 a barrel.