OPEC, Russia, and other countries controlling 60% of global crude production have extended their withholding of 1.8 million bbl/day of oil, 2% of output, from 3/31/18 to 12/31/18. The forces at play here are threefold; rising global GDP boosting demand by 500,000 bbl/day, declining production in Venezuela and Kurdistan due to political and economic factors, and rising US shale production. If shale output rises substantially, the deal dies prematurely.