(Reuters) – Oil prices are likely to rise this year thanks to supply disruptions and an OPEC-led deal to limit production, but doubts over the future of compliance with the multilateral agreement and rising U.S. production could stem the upward momentum, a Reuters poll showed on Thursday. A survey of 31 economists and analysts polled by Reuters showed Brent crude LCOc1 would average nearly $64 a barrel in 2018, versus $63 forecast in the February survey, but below the $67.18 average for the benchmark so far in 2018. Brent prices have risen 4 percent this year, supported by a deal between the Organization of the Petroleum Exporting Countries and non-OPEC producers led by Russia to curb output by about 1.8 million […]