The world according to gas

Abstract

Proven global reserves of conventional natural gas are immense, with some 5500 × 10 12 SCF recognized world-wide, sufficient for around 60 years supply at current global gas production rates. However, total global growth in demand for gas is expected to average 3.2% over the coming decade and is projected to double by 2025. Along with accelerating liberalization of gas markets, this growth in demand will generate huge opportunities for gas explorers and producers. The exploration and reservoir engineering challenges are to find and produce three times more gas over the next 20 years than the industry has found in cumulative total since 1970. Current estimates suggest that 50% of conventional gas resources have been discovered to date. These resources are well characterized and exploration will have to extend deeper into sedimentary basins, in deeper waters, and in new plays, as well as creatively re-evaluate current acreage, to discover additional conventional natural gas. Tertiary deltas will be a major exploration play over the next decade. In the future, unconventional gas resources will be used increasingly to supplement high volume demand in developed markets and as a major longer-term source of energy. Natural gas in low permeability sandstone reservoirs, coal beds and fractured shale already accounts for more than 25% of natural gas production in the USA. Additionally, enormous volumes of natural gas are generated by methanogenic bacteria during early burial in marine sediments, much of which then contributes to frozen methane hydrates on the continental slopes. At present, much of this unconventional natural gas is categorized as hypothetical and requires fundamental scientific research before it can be considered as an economic resource. Historically, the commercial imperative has been to find gas close to markets. Shipping of liquefied gas, liquid gas derivatives and potentially solid methane hydrates (LNG, GTL and GTS technologies) around the globe, are changing the traditional patterns of gas exploration, transportation and market supply as new producers and demand centres emerge. LNG has already been transformed from a small volume, exotic trade into a sophisticated global market and GTL is likely to follow, opening global gas exploration and production to deep waters and plays far removed from markets.