Transcript for The Future of Energy Gases, segment 10 of 13
Certainly knowing something about the origin and occurrence of natural gas can better help us understand discussions of domestic energy policy, but as consumers who depend upon energy, we'd really like to know how far into the future these supplies will be available and at what coss. The U. S. Geological Survey and other organizations regularly make forecasts regarding the amounts of oil and gas that remains undiscovered, both within the United States and throughout the world.
Estimating the amount of a resource hidden in the Earth is a little like guessing the number of jelly beans in a very large jar. Even if you could count the ones you see, there's all that stuff in the middle that's jumbled up and out of sight. But the jelly beans fill the jar, while natural gas is only scattered through the Earth's crust, making resource estimation even more difficult than jelly bean guessing. Information is limited to the production histories of known gas fields and basins and the new discoveries that come online, but we must also consider the natural gas that lies still untouched, and estimating this requires an educated guess.
Through the years the careful procedures of resource estimators have tended to underestimate the amount of natural gas available for our use. Widely accepted estimates of natural gas resources now project an available supply in the United States of twelve hundred to fifteen hundred trillion cubic feet or T. C. F. Today we use about twenty T. C. F. per year so there's enough natural gas available to fulfill present needs for about seventy-five years. If we used forty T. C. F. per year, double the present rate, supplies would last nearly forty years, and remember these are conservative estimates and don't take into account the potential supplies of deep gas or gas hydrates.
But it is not quite this simple because supplies of natural gas are in part related to price. As price increases, producers will put more money into development of resources - coalbed methane or tight gas, for example - that were once unprofitable so as price rises and sources that were once uneconomic begin to be developed, more natural gas becomes available. There is, of course, a limit to this increase, but the development of natural gas is at an early stage and the upper limits of supply are still not known.