A worker checks the valves at Al-Sheiba oil refinery in Basra, Iraq, January 26, 2016. OPEC and rival oil producers are meeting in Kuwait on Sunday to review their progress with a global pact to cut supplies and may discuss whether the agreement should be extended beyond June to help stabilize the market. The Organization of the Petroleum Exporting Countries and 11 other leading oil producers including Russia agreed in December to cut their combined output by almost 1.8 million barrels per day (bpd) in the first half of the year. The accord, aimed at supporting the oil market, has lifted crude to more than $50 a barrel. But the price gain has encouraged U.S. shale oil producers, which are not part of the pact, to boost output. OPEC Secretary-General Mohammed Barkindo is investigating whether the deal needs to be extended, Iraqi Oil Minister Jabar Ali al-Luaibi […]