In the 80's, OPEC tied the amount of oil a country can produce to their stated reserves. This led to the OPEC countries steadily increasing their stated reserve

In the 80's, OPEC tied the amount of oil a country can produce to their stated reserves. This led to the OPEC countries steadily increasing their stated reserves. This, combined with heavy and unconventional reserves being found in South America and Canada, has resulted in a huge increase of stated world oil reserves. The cost of extraction is not factored in to this figure though. This does mean that we will never "run out of oil", but the cost of extracting it will steadily increase, causing other energy sources to eventually become economical or palatable (eg, nuclear, or coal - there's loads of coal still. Good luck stopping China from powering its economy with coal for the next 100 years).