Investing.com - Crude oil prices have been touching new two and a half years highs at the start of the year, but analysts don't expect a rally in 2018.Most see prices in the mid $50 to low $60 range. For instance, a recent Reuters poll of about three dozen economists and analysts called for Brent North Sea crude to average about $60 a barrel in 2018. The West Texas Intermediate average was about $56..In fact, that's less than new-year levels of $67 for Brent and $61 for WTI.Analysts say current prices reflect a bit of a boost from concerns that civil unrest in major oil producer Iran could lead to supply disruption. Without that happening, market watchers say prices are bound to decline a bit. The other risk to prices is supply. Right now, solid global demand, especially from China, and reduced production from OPEC and Russia, are supporting the market.If major producers don't stick to previously agreed production cuts, prices will suffer.