Here's a great map showing how the world's gas deposits are distributed.
CBM stands for coal bed methane. Cumulative production is the difference in how much gas has been extracted versus magnitude of gas deposits known to exist. The rest is pretty self-explanatory.
Read more: http://www.businessinsider.com/map-worl ... z1wXBvifNw
"The global natural gas resource base is vast and widely dispersed geographically. Conventional recoverable resources are equivalent to more than 120 years of current global consumption, while total recoverable resources could sustain today's production for over 250 years."