Eyes will be on the 166th OPEC Meeting in Vienna to see whether the bloc moves to calm global fears that turmoil in several member countries will disrupt the supply and price of oil.
Although OPEC has no influence on non-OPEC production and rarely influences its members' oil production rate, the common perception is that OPEC has power and so OPEC announcements can influence markets.
Fears of disruption rocketed following the apparent success of Islamic militants fighting their way to Baghdad in Iraq, the second-biggest OPEC producer and the city where the organization was founded in 1960. As a calming measure, the organization agreed in June 2014 to keep its petroleum production target at 30 million barrels a day for the rest of the year.
Export from Libya and Nigeria has also been disrupted by problems that include violence, political turmoil and theft. International sanctions prevent Iran pumping at normal levels.
The 12 members of OPEC are: Angola, Ecuador, Iran, Iraq, Kuwait, Libya, Nigeria, Qatar, Saudi Arabia, United Arab Emirates, Venezuela and Indonesia.
Date written/update: 2014-07-10