As 2017 draws to a close, oil is rallying hard as OPEC supply cuts — combined with improving global demand — support the market.

Next year, however, is a different story. We see two conflicting views for crude in the coming year that could weigh on oil prices.

On Tuesday, WTI crude surged to its highest level since mid-2015, surpassing the $60-per-barrel milestone right before it settled, as an explosion at a pipeline in Libya prompted the loss of around 90,000 barrels of crude.

Looking ahead, OPEC's optimistic view assumes its supply cuts will remain in effect, and the global supply glut will finally clear from the market. This view runs into some problems.

For example, the International Energy Agency warns of the potential for U.S. shale to continue to suck up market share, leaving the broader market in a less-than-ideal scenario. We tend to be more cautious in our outlook, but I see 2018 in two distinct parts.