Peak oil – the point in time at which the highest rate of oil extraction has been reached, and after which world production will start decline. Many geologists and the International Energy Agency say the world's crude oil output reached its peak in 2006. But while there may be less oil coming out of the ground, the demand for it is definitely on the 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. Nationalisation 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 secnd 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. Mainly state-owned, the new Seven Sisters control a third of the world's oil and gas produ