What is gas hydrate, and thermogenic and biogenic gases?
Both thermogenic and biogenic natural gases have the same quality, but differ radically in their origin. Thermogenic gas is the natural gas formed from organic matter in the rock under the influence of heat deep inside the earth. Most of the world’s gas deposits, including the ones in Bangladesh, are thermogenic in origin, and are referred to as conventional natural gas. Biogenic natural gas, on the other hand, requires no heat, and is generated from organic matter by the action of bacteria at a very shallow depth. Therefore, in areas where geothermal gradient is low — meaning there is less heat available underground — biogenic gas still holds promise. Because of the low geothermal gradient, thermally mature rock is not easily found underground, which is one drawback for the prospect of gas in Bangladesh. Therefore, the existence of biogenic gas in the deep-water neighbourhood of Bangladesh is promising in that respect. Even more unconventional is the geoscientists’ interpretation re
