The growth of production from the Canadian oil sands and the associated upgrading, refining and chemical industries all rely heavily on conventional natural gas resources. Natural gas production in the Western Canadian Sedimentary Basin (WCSB), however, has reached a plateau and has begun to decline. In addition the highest natural gas prices in the world are found in North America. The declining supply and high prices provide urgency to decrease the dependence on natural gas. The availability of vast quantities of unconventional gas (coal bed methane, tight and sour gas) provides opportunities to replace the declining conventional gas resources. However very significant technical challenges remain to achieve economic production for the majority of these resources. In addition to unconventional gas a large range of feedstocks (coal, petroleum coke, oil sands residue and biomass) are available in Alberta that are ideally suited for gasification technology to produce power, hydrogen, steam, and chemicals that are currently being produced by using natural gas. Indeed the first commercial gasifier in Canada which will become the largest liquid feed gasifier in the world is being constructed by Opti-Nexen and will be operational by 2009. Several other companies are in the design and engineering phases for using gasification. This presentation will review the important geological and reservoir characteristics of the unconventional gas resources in the WCSB and the recovery processes being tested or developed. As well, the presentation will describe the features and benefits of shifting to the use of gasification technology, including minimizing the environmental risks associated with water use, CO2 and other emissions.
The world's consumption of natural gas is expected to grow faster than any other energy commodity (1). The world conventional gas reserves amount to 181 trillion m3 (6,400 trillion cubic feet or Tef) (2). The unconventional gas reserves found in basins around the world make up an even larger portion of the world's natural gas reserves. Not including methane hydrates, the rough estimate is that the unconventional gas reserves are 907 trillion m3 (32,400 Tcf) (3,4). This includes:. 207 trillion m3 (7,400 Tef) in tight gas sands. 252 trillion m3 (9,000 Tcf) natural gas in coal beds; and. 448 trillion m3 (16,000 Tef) natural gas in shale. In most of the world, the focus is on conventional natural gas and unconventional gas resources have been largely overlooked. With the peaking of conventional gas resources in the U.S. and more recently in Canada, however, there is a growing emphasis on unlocking the potential of these complex-to-produce unconventional resources. Indeed, new technologies developed in the U.S. over the past several decades coupled with an understanding of the geological features and gas mobilization characteristics have boosted production levels of unconventional gas to about 30% of the natural gas production in that country (3). The technologies developed in the U.S. are being rapidly adapted to unconventional gas resources in Canada through the efforts of both the major service companies and producing companies with U.S. experience.
