The age of unconventional gas: tight gas reservoirs; the potential economic impact and local industry reality check

With the decline of production and increase in demand of fossil-fuel, economically producing gas from unconventional sources is a great challenge today. The large volume and long-term potential, attractive gas prices and unprecedented interest in world markets, brings the unconventional gas into the forefront of our energy future. An unconventional reservoir is one that cannot be produced as economic flow rates or that does not produce economic volumes of oil and gas without assistance from massive simulation treatments or special recovery processes and technologies, such as steam injection. Typical unconventional reservoirs are tight-gas sands, coal-bed methane, heavy oil and gas shales. Law and Curtis (2002) defined low-permeability (tight) reservoirs as having permeabilities less than 0.1 milidarcies. With a dimming possibility of economically viable alternative sources of energy in near future, ever widening gap between the energy demand and supply and the decline of production of conventional fossil-fuel, the thrust on unconventional sources of gas (tight Gas etc) is glowingly increasing world-over. With the successful marketing of natural gas as an environmentally-friendly fuel, demand of gas has increased sharply in the opening years of the 21st century. Some experts believe that gas consumption may exceed that of the oil by the year 2025. Tight reservoirs contain no natural fractures, and cannot be produced economically without hydraulic fracturing fractured, tight and unconventional reservoirs are often perceived as entailing higher costs and risks than conventional reservoirs. However, new technologies developed in recent years are making more and more of these accumulations economical. The U.S. currently produces substantial volumes of natural from tight sands, gas shales, and coalbed-methane reservoirs. The tight gas reservoirs till date have been greatly ignored as gas sources in South Asia(196 Trillion cu.ft of discovered reserves compared to 1371 Trillion cu.ft proven reserves of North America alone)and particularly in Pakistan. A lot greater area yet remains unexplored in Pothohar and off-shore regions. This paper deals with the description of the tight gas reservoirs, improvement in their production, its economic impact worldwide and potential impact upon the current Natural gas crisis in the local industry. (author)