What is Coalbed Methane?
In Alberta, methane gas produced from coals seams is generally referred to as Coalbed Methane Gas (CBM). CBM gas is the same natural gas that we use to heat our homes and generate electricity. This is why the terms methane gas and natural gas are often used interchangeably. For the purposes of this website we will refer to the gas as Coalbed Methane (CBM).
CBM is one of the cleanest burning fossil fuels. The gas is considered to be sweet, meaning it has minimal to no additional gases or chemicals thereby reducing any health and safety issues associated with its production. This is different from sour gas which contains Hydrogen Sulfide (H2S). Because CBM has relatively little additional gases or chemicals within its composition it requires little to no refining. In other words, from the moment that CBM is first extracted from the coal seams it is ready to heat to your home.
Why is CBM Referred to as an Unconventional Gas
Some times you may hear CBM referred to as an unconventional resource. While the production of CBM in Canada is relatively new, the term does not apply to the recent interest in production of this resource. Rather, the term applies to the method in which the gas is stored in the earth, and the impact this has on how it is produced.
Most CBM is stored within the molecular structure of the coal and is held in place by the pressure of the overlying rock and, in many cases, by water circulating through the coal seam. To produce this gas, the pressure must be reduced in the coal seam before the gas can flow through existing fractures, or cleats, within the coal seam up to the pipeline.
In contrast, conventional gas is often found pooling within spaces found naturally within the rock formation itself. Since conventional gas is not attached (adsorbed) onto the rock formation, extraction is as simple as drilling into the rock formation and, with the assistance of pumping systems, extracting the gas out of the reservoir pores and into the pipeline.