Oil prices edged lower on Friday but are set for their biggest weekly gains since last July following a jump to a more than three-year high earlier in the week on tensions over Syria and shrinking global oil inventories. NYMEX crude for May delivery was down 23 cents, or 0.3 percent, at $66.84 a barrel at 0148 GMT, after settling up 25 cents on Thursday.\u00a0London Brent crude was down 25 cents, or 0.3 percent, at $71.77 after settling down 4 cents. Both contracts are set to rise around 7 percent for the week, the biggest weekly gain since July.\u00a0A global oil stocks surplus is close to evaporating, OPEC said on Thursday, citing healthy energy demand and its own supply cuts while revising up its forecast for production from rivals who have benefited from higher oil prices. OPEC and its oil producer allies are poised to extend their supply-cutting pact into 2019 even as a global glut of crude is set to evaporate by September, OPEC Secretary-General Mohammad Barkindo told Reuters in an interview. Oil prices jumped on Wednesday to their highest level since late 2014 after Saudi Arabia said it intercepted missiles over Riyadh and U.S. President Donald Trump warned of military action in Syria, both of which raised concerns about possible supply disruptions.