Global availability of natural gas: resources, requirements and location

Abstract

In the past few years, the enormous significance of the largely untapped global natural gas resource has received increasing attention. Initially, gas was viewed as one component of a strategy to moderate the world's increasing dependence upon liquid petroleum. More recently, the low air pollutant emissions and the relatively low contribution to the so-called 'greenhouse' gases which result from the combustion of natural gas compared to those of other fossil fuels, have given the gas option greater emphasis. Today, discussions of acid rain controls and of more comprehensive measures to moderate man-made contributions to global warming usually include some consideration of natural gas. Greater reliance upon gas is viewed as an interim measure to bridge the gap between business as usual and a future energy balance which minimizes fossil fuel dependence. The natural gas resource base is quite large in relation to the current levels of demand upon it. Proved reserves of natural gas, those amounts which are reasonably well known based upon drilling information, are estimated to be the energy equivalent of about 740 billion barrels of crude oil. This approaches the size -of global proved reserves of oil (896 billion bbls), but the annual production of natural gas is only about half that of petroleum. The global reserve to production ratio for natural gas, a measure which is often used as an indication of near-term supply capability, is, therefore, about 60 to 1. In comparison the ratio for petroleum is 40 to 1. The estimated total remaining worldwide gas resource base which could be economically recoverable with current technology is much larger than the proved reserves. Estimates of total remaining recoverable reserves, which include undiscovered portions of the resource base, are on the order of 1.5