Whither global oil flows?

Oil shipments: Oil tankers pass the skyline of Singapore. Through the first nine months of this year, Saudi Arabia shipped about 3.1 million barrels a day to key Asian nations including China, Japan and South Korea. – Reuters

OPEC’S quest to end a global crude glut already snapped a two-year slump in oil prices.

Now attention is turning to how the group’s surprise decision to cut output will transform international trade flows of the world’s most important commodity.