Coalbed Methane In Alberta

Abstract

Abstract Alberta's coalbed methane (CBM) resource has been estimated to be comparable in size to that of the province's conventional natural gas resource base. Although only limited drilling for CBM targets has occurred in the province to date, considerable interest in how development of this resource might proceed has been shown by the gas and coal industries, the public, and regulatory agencies. Because CBM is a form of natural gas, it is regulated in the same manner as other natural gas. An overview of CBM in Alberta is given, including the potential resource base, elaboration on the application of natural gas regulations to CBM, activity to date, and some of the main regulatory issues and initiatives that have arisen. It is shown that there is a need to collect Alberta specific CBM data before decisions can be made on the necessity of regulatory change specifically for CBM development. Introduction Numerous papers and articles have been published over the past few years on various aspects of CBM. The growing number of CBM wells and increasing amount of CBM production in the United States (USA) has caused somewhat of a surge in published case histories and field experiences for the major CBM basins ill that country. Much less CBM field experience currently is available for Alberta, but the potential CBM resources of the province have not been overlooked. Early investigations into the production of CBM in Alberta date back to the late 1970's, but interest waned in the early to mid 1980's with falling gas prices and a levelling in gas demand. The more recent interest in CBM development ill Alberta was spurred on by the surge in CBM activity that occurred in parts of the USA from 1989 to 1992. A summary of the current CBM situation in Alberta is given in this paper. The province's CBM resource potential and regulatory framework are overviewed along with activity to date and some of the issues that have been raised regarding the development of this resource. Why the Interest in Coalbed Methane in Alberta? The recent interest in CBM in Alberta can be attributed to three main factors:the large CBM resource potential of the province.the large amount of recent CBM development activity in the USA, andenvironmental concerns regarding the development of CBM in Alberta. Alberta's Coalbed Methane Resource Potential CBM is a naturally occurring hydrocarbon gas, consisting largely of methane, that is generated by and stored in coal seams. Because Alberta has extensive coal deposits, it follows that the CBM resource associated with these deposits has the potential to be significant. Coals of varying thermal maturity, or rank, underlie about 45 per cent of the province(1), with essentially all of the coals being located south of Township 75 as shown ill Figure I. These coals are associated with Upper Jurassic, Cretaceous, and Lower Tertiary strata as shown in Figure 2, and much of it may be of suitable rank to hold potential for CBM development.