July 13 (UPI) -- Oil market investors are losing confidence over OPEC's effort to offset the glut of supplies, though the impact could be hitting U.S. producers, the IEA said.
The Organization of Petroleum Exporting Countries and a handful of non-member producers in January started implementing a deal to curb output to offset the supply-side strains that pushed oil prices below $30 per barrel in early 2016.
Member states Libya and Nigeria are not participating in the deal so they can steer oil revenue toward national security efforts. Iran is the only member state that has room for production growth so it can regain a market share lost to sanctions. Of the three, Libya and Nigeria are regaining ground rapidly, adding about a quarter million barrels of new oil to the market each day.
With oil prices lingering below yearly highs, a report Thursday from the International Energy Agency said those are just some of the factors rattling investors' nerves.
"Oil investors are going through a period of waning confidence with prices recently returning to levels not seen since early November," its report read. "Each month something seems to come along to raise doubts about the pace of the re-balancing process."
By the IEA's estimate, it's not just three members undermining OPEC's efforts. Total compliance in the deal is at about 78 percent, down from the 95 percent reported in May.
U.S. crude oil production, meanwhile, has proven more resilient to historically low crude oil prices than initially expected as operators in the shale basins in the Lower 48 become more efficient. U.S. oil production has been strong relatively speaking, though lower oil prices in June led to brief declines in output, as well as exploration and production activity.
"Such is the resilience of the U.S. shale sector that we should be careful to pronounce that its expansion will slow, however it could be that the recent exuberance is being reined in," the IEA's report read. "Financial data suggests that while output might be gushing, profits are not."