How is natural gas from coal formed?
Like conventional natural gas, NGC is the result of heat and pressure acting on organic matter. In the case of NGC, however, natural gas generation is part of the coalification process and the natural gas thus created remains stored within the coal, instead of migrating to other reservoir quality rocks such as sandstone. Coal originates from the transformation of terrestrial plants into carbon through burial. As trees and other plants growing in ancient forests and swamps died and decayed, their remains formed peat bogs. Over time, the bogs were buried by sediments, and as the depth of burial increased, the peat was subjected to increasing temperature and pressure. This resulted in a decrease in moisture content and an increase in the relative proportion of carbon. By-products of this process include water, carbon dioxide, nitrogen and methane. The organic matter was transformed sequentially through the different stages or ranks of coal – lignite, sub-bituminous, bituminous and anthrac
