The new reserves data also distinguishes between reserves in existing fields, in new projects, and potential reserves in recent discoveries and even in yet undiscovered fields. An established standard approach for estimating reserves is applied to all fields in all countries, so reserves can be compared like for like across the world, both for OPEC and non-OPEC countries. Other public sources of global oil reserves, like the BP Statistical Review, are based on official reporting from national authorities, reporting reserves based on a diverse and opaque set of standards.

Some OPEC countries such as Venezuela report official reserves apparently including yet undiscovered oil, while others such as China and Brazil officially report conservative estimates and only for existing fields.

Rystad Energy now estimates total global oil reserves at 2,092 billion barrels, or 70 times the current production rate of about 30 billion barrels of crude oil per year. For comparison, cumulatively produced oil up to 2015 amounts to 1,300 billion barrels. Unconventional oil recovery accounts for 30% of the global recoverable oil reserves while offshore accounts for 33% of the total. The seven major oil companies hold less than 10% of the total.

This data confirms that there is a relatively limited amount of recoverable oil left on the planet. With the global car-park possibly doubling from one billion to two billion cars over the next 30 years, it becomes very clear that oil alone cannot satisfy the growing need for individual transport.