The Organization of the Petroleum Exporting Countries (OPEC, /ˈoʊpɛk/ OH-pek) is an organization enabling the co-operation of leading oil-producing countries, in order to collectively influence the global market and maximise profit. Founded on 14 September 1960 in Baghdad by the first five members (Iran, Iraq, Kuwait, Saudi Arabia, and Venezuela), it has, since 1965, been headquartered in Vienna, Austria, although Austria is not an OPEC member state. As of September 2018, the 13 member countries accounted for an estimated 44 percent of global oil production and 81.5 percent of the world's proven oil reserves, giving OPEC a major influence on global oil prices that were previously determined by the so-called "Seven Sisters" grouping of multinational oil companies.

The formation of OPEC marked a turning point toward national sovereignty over natural resources, and OPEC decisions have come to play a prominent role in the global oil market and international relations. The effect can be particularly strong when wars or civil disorders lead to extended interruptions in supply. In the 1970s, restrictions in oil production led to a dramatic rise in oil prices and in the revenue and wealth of OPEC, with long-lasting and far-reaching consequences for the global economy. In the 1980s, OPEC began setting production targets for its member nations; generally, when the targets are reduced, oil prices increase. This has occurred most recently from the organization's 2008 and 2016 decisions to trim oversupply.
From the passage below, extract the first five member countries of OPEC
The first five members of the Organization of the Petroleum Exporting Countries (OPEC) were Iran, Iraq, Kuwait, Saudi Arabia and Venezuela. As of September 2018, OPEC officially has 13 member countries.