water depths in offshore areas, economics, and
technological factors.
There has been a huge disparity between “proven” reserves and potential
reserves. Even in the case of the highly mature and exploited United States,
depending upon information sources, the potential remaining gas reserve
estimates vary from 650 Tcf to 5,000 Tcf (Economides et al. 2001). Proved
natural gas reserves in 2000 were about 1,050 Tcf in the United States and
170 Tcf in Canada. On the global scale, it is more difficult to give a good