Investing.com - (NYSE:Goldman Sachs) sees Brent at $59 a barrel in the first half of next year.
The U.S. investment back sees a compliance level of 84% in agreed cuts of around 1.8 mn b/d.
OPEC has agreed to cut by 1.2 mn b/d, non-OPEC producers by 558,000 b/d.
Goldman Sachs noted compliance by non-Gulf Cooperation Council producers "has historically been poor."
It sees Russia freezing output at current levels.
Full compliance would add $6 a barrel to upside of its current estimate.
It sees little upside beyond high $50s a barrel level as more shale activity comes into play.