Peak oil is the point in time when the maximum rate of petroleum extraction is reached, after which the rate of production is expected to enter terminal decline. Many geologists and the International Energy Agency say the world's crude oil output reached its peak in 2006.
While there may be less oil coming out of the ground, the demand for it certainly continues to rise.
The final episode of this series explores what happens when oil becomes more and more inaccessible, while at the same time, new powers like China and India try to fulfill their growing energy needs.
And countries like Iran, while suffering international sanctions, have welcomed these new oil buyers, who put business ahead of lectures on human rights and nuclear ambitions.
At the same time, oil-producing countries have had enough with the Seven Sisters controlling their oil assets. Nationalization of oil reserves around the world has ushered in a new generation of oil companies all vying for a slice of the oil pie.
These are the new Seven Sisters.
Saudi Arabia's Saudi Aramco, the largest and most sophisticated oil company in the world; Russia's Gazprom, a company that Russia's President Vladimir Putin wrested away from the oligarchs; The China National Petroleum Corporation (CNPC), which, along with its subsidiary, Petrochina, is the world's second largest company in terms of market value; The National Iranian Oil Company, which has a monopoly on exploration, extraction, transportation and exportation of crude oil in Iran – OPEC's second largest oil producer after Saudi Arabia; Venezuela's PDVSA, a company the late president Hugo Chavez dismantled and rebuilt into his country's economic engine and part of his diplomatic arsenal; Brazil's Petrobras, a leader in deep water oil production, that pumps out 2 million barrels of crude oil a day; and Malaysia's Petronas - Asia's most profitable company in 2012.
Primarily state-owned, the new Seven Sisters control a third of the world's oil and gas production, as well as a third of the world's reserves. The old Seven Sisters, by comparison, produce a tenth of the world's oil, and their control has dwindled to only three percent of the reserves.
The balance has shifted.