Drilling for coalbed methane
With mounting apprehension over climate change and energy security, the world is becoming increasingly concerned with fuel efficiency. However, while fuel efficiency is diligently scrutinized, the efficiency of fuels is often overlooked.
Not all fuels are alike. For example, anthracite coal has a calorific value of 27 megajoules per kilogram (MJ/kg). Gasoline’s is 47.3 MJ/kg, while methane’s is 55.5 MJ/kg. This means that, ounce for ounce, methane yields twice the energy that anthracite does.
So, should the energy industry abandon its search for oil and coal and look for gas instead? No, but we surely should be extracting gas at every available opportunity. Fortunately, a lot of the known reserves of methane are associated with known deposits of coal, in the form of coalbed methane (CBM).
CBM refers to methane that lies adsorbed in coal’s matrix. CBM differs from conventional gases in that methane is in a near-liquid state, lining pores within the coal. CBM also contains very little heavier hydrocarbons and no natural gas condensate. For CBM to be released, the coal seam has to be depressurized by means of wells. This allows methane to desorb from the coal and flow as a gas up the well to the surface.
Speaking for the fuel of choice
One body that fully understands the merits of CBM Calgary-based Canadian Society for Unconventional Gas (CSUG), which supports and promotes the exploration and development of unconventional gas resources. A not-for-profit member-based organization with about 130 members, CSUG is funded by its members, who, according to CSUG president Mike Dawson, “are energy companies of varying sizes — from the big majors to the small independents, service sector companies, consultants and some government representatives.”
Bringing about better communication between the unconventional gas industry and various levels of government, communities, stakeholders and First Nations is an important part of CSUG’s mandate. To fulfil it, the society relies on the fund of expertise its members share. “We provide information, take on speaking engagements, develop media material, and maintain a comprehensive website,” says Dawson. “Our greatest strength is in the provision of factual, timely information about unconventional gas to our wide and diverse audience.”
While things have come a long way over the past few years, CSUG’s work is still challenging. “As the industry expands into areas where oil and gas have not traditionally been explored, there commonly is hesitation and resistance among communities and residents who wonder what natural gas exploration would look like,” Dawson continues. “Our role is to be a resource that all parties who may be potentially affected by development can utilize to improve their knowledge about the unconventional gas industry.”
Part of the problem stems from nomenclature. “People hear the word ‘unconventional’ and become concerned,” says Dawson. “Actually, unconventional gas is simply natural gas from unconventional sources.” He adds that over and above providing information to stakeholders and communities, engendering an understanding among government agencies about the nuances of unconventional gas is also an important role of the society. “Just because it’s natural gas, does not mean that reservoirs can be treated in the same way as conventional gas,” explains Dawson “Regulations need to reflect these differences.” However, he adds, “The government is responding to some of the concerns we have raised and is becoming more supportive.”
From the perspective of energy security in North America, CBM and other unconventional gas sources are very important indeed. “If there was a large-scale switch to natural gas utilization in the transportation sector, there could be a significant offset of imported oil,” Dawson says. “More important, however, is the role that natural gas can play in both Canada and United States in achieving greenhouse gas emission reduction targets. Natural gas is the cleanest form of energy from hydrocarbon-based fuels and is abundant through much of North America. That’s a good-news–bad-news thing for Canada because we export a lot of oil. But there is the opportunity for Canada and North America to increase the utilization of natural gas and reduce emissions. To achieve this fundamental shift in energy supply would take a strong commitment by government, but it is doable.”
Dawson’s view is that “natural gas should be the energy fuel of choice from the environmental point of view if we are to balance ecological concerns with economic sustainability.”