The question of the cartel's efficacy are yet again the focus of attention Monday.
Saudi Arabia and other Arab states cutting ties with Qatar was singled out as the cause for West Texas Intermediate on Monday falling 26 cents to $47.40 and Brent dropping 50 cents to $49.45 per barrel; but analysts dismiss the rift as having minimal long-term impact and point again to the machinations of the Organization of the Petroleum Exporting Countries (OPEC) as a far more potent source of market discontent.
Chris Gersch, director of strategy at Bell Curve Capital, told Bloomberg television, "the bears are in full effect right now in the oil futures."
He went on to say that "We might test those $44.13 lows," but he added that compliance among Arab producers has been achieved over the years despite wars and other issues: "everyone really knows where their bread is buttered, so we expect this infighting really not to have any effect and the momentum to stay lower."
Mike Wittner, Societe Generale SA
The market wants to see it before it believes it
The "real deal," said Bob Yawger, director of the futures division at Mizuho Securities USA Inc., "is that the OPEC folks needed to take barrels off the market; their failure to do so opens the door for, at the least, an increase in U.S. shale production.
"The market's not buying their story anymore."
Mike Wittner, head of commodities research at Societe Generale SA, agreed: "The market wants to see it before it believes it," he said, referring to OPEC's repeated assurances that its recently agreed-to production cutback extension will bring about true market rebalance - despite the fact the cartel is only cutting for longer and not deeper.
Another OPEC-related factor that may be giving investors the jitters is news on Monday from Thomson Reuters Oil Research that the cartel's shipments likely jumped to 25.18 million barrels per day in May, up over 1 million bpd from April.
Yet another possible factor: Russian oil firm Rosneft vowing to step up production if the OPEC cutbacks are suddenly terminated.
Igor Sechin, chief executive for Rosneft, told the Financial Times over the weekend that "if the question is how OPEC is going to exit from these arrangements abruptly, we will also be prepared.
"If something goes wrong, we will not let them occupy our markets: we'll defend ourselves."
However, the Qatar spat should not be entirely overlooked, said JBC Energy in a note: "While we would not want to read too much into this in terms of looming trouble for OPEC, the fact that Qatar's stance towards Iran is a key element in this issue does make for a potentially more complicated setup at future meetings should the issue not have been resolved in due time."
One thing is certain: any mention of OPEC and its allies is likely to cause prices to fall, as was the case last week when the highly-touted "Catholic marriage" between Saudi Arabia and Russia was greeted with a nearly 3 percent price drop.