Global natural gas reserves (conventional and unconventional)
The Reserves-to-Production ratio (R/P) in years represents the availability of a non-renewable resource under current technical and economic conditions.
Estimated reserves cover unconventional natural gas deposits (see the Glossary), but also conventional natural gas deposits that cannot be worked today with existing technologies.
Unconventional gas represents more than half of estimated resources, in particular in the United States where the sector has allowed the country to reduce its energy dependency rate. Also note the reserves in Asia Pacific, thought to be larger than the North American reserves. The R/P ratio is approximately 60 years, taking proven resources into account only. With estimated resources, the total comes to 250 years.