The world’s total endowment of oil is large enough to support the projected rise in production beyond 2030 in the Reference Scenario.
The world’s total endowment of oil is large enough to support the projected rise in production beyond 2030 in the Reference Scenario. Estimates of remaining proven reserves of oil and NGLs range from about 1.2 to 1.3 trillion barrels (including about 0.2 trillion barrels of non-conventional oil). They have almost doubled since 1980. This is enough to supply the world with oil for over 40 years at current rates of consumption. Though most of the increase in reserves has come from revisions made in the 1980s in OPEC countries rather than from new discoveries, modest increases have continued since 1990, despite rising consumption. The volume of oil discovered each year on average has been higher since 2000 than in the 1990s, thanks to increased exploration activity and improvements in technology, though production continues to outstrip discoveries (despite some big recent finds, such as in deepwater offshore Brazil). Ultimately recoverable conventional oil resources, which include initial proven and probable reserves from discovered fields, reserves growth and oil that has yet to be found, are estimated at 3.5 trillion barrels. Only a third of this total, or 1.1 trillion barrels, has been produced up to now. Undiscovered resources account for about a third of the remaining recoverable oil, the largest volumes of which are thought to lie in the Middle East, Russia and the Caspian region. Non-conventional oil resources, which have been barely developed to date, are also very large. Between 1 and 2 trillion barrels of oil sands and extra-heavy oil may be ultimately recoverable economically. These resources are largely concentrated in Canada (mainly in Alberta province) and Venezuela (in the Orinoco Belt). The total long-term potentially recoverable oil-resource base, including extra-heavy oil, oil sands and oil shales (another largely undeveloped, though costly resource), is estimated at around 6.5 trillion barrels. Adding coal-to-liquids and gas-to- liquids increases this potential to about 9 trillion barrels. Globally, natural gas resources are large, but, like oil, are highly concentrated in a small number of countries and fields. Remaining proven reserves amount to 180 tcm — equal to around 60 years of current production. Three countries — Russia, Iran and Qatar — hold 56% of the world’s reserves, while just 25 fields worldwide hold almost half. OPEC countries also hold about half. Remaining reserves have more than doubled since 1980, with the biggest increases coming from the Middle East. Although the size of gas discoveries has been steadily declining in recent decades in the same way as for oil, discoveries continue to exceed production. Ultimately recoverable remaining resources of conventional natural gas, including remaining proven reserves, reserves growth and undiscovered resources, could amount to well over 400 tcm. Cumulative production to 2007 amounts to less than one-sixth of total initial resources. Non- conventional gas resources — including coalbed methane, tight gas sands and gas shales — are much larger, amounting perhaps to over 900 tcm, with 25% in the United States and Canada combined.