Petroleum prices

The price of oil, or the oil price, generally refers to the spot price of a barrel of benchmark crude oil—a reference price for buyers and sellers of crude oil such as West Texas Intermediate (WTI), Brent ICE, Dubai Crude, OPEC Reference Basket, Tapis Crude, Bonny Light, Urals oil, Isthmus and Western Canadian Select (WCS). There is a differential in the price of a barrel of oil based on its grade—determined by factors such as its specific gravity or API and its sulphur content—and its location—for example, its proximity to tidewater and/or refineries. Heavier, sour crude oils lacking in tidewater access—such as Western Canadian Select— are less expensive than lighter, sweeter oil—such as WTI.

In 1960 the Organization of the Petroleum Exporting Countries (OPEC) was founded in Baghdad, Iraq by its first five members —Iran, Iraq, Kuwait, Saudi Arabia and Venezuela—, with Qatar and Libya joining immediately, followed by United Arab Emirates, Algeria, Nigeria, Ecuador and Gabon after a decade. The goal of these countries was to increase its influence in the world oil market, then dominated by a cartel known as the "Seven Sisters", five of which were headquartered in the United States. These companies had been controlling posted prices since the so-called 1927 Red Line Agreement and 1928 Achnacarry Agreement, and had achieved a high level of price stability until 1972.Angola joined the OPEC in 2007 and Equatorial Guinea in 2017.