This paper will introduce a novel source of unconventional gas, called Underground Coal Gasification (UCG), also known as In-Situ Gasification (ISG), which has been around for a long time. Due to the inexpensive cost of oil and gas, along with the abundance of coal and the low cost of mining coal seams close to the surface, UCG has not attracted a lot of attention in the past. With the demand and price for gas increasing and the move away from mining coal, UCG is becoming more attractive as a way of extracting energy from deep uneconomic coal deposits and at the same time, lowering GHG emissions and reducing the environmental impact to the landscape.
With the majority of the world's coal deposits being uneconomic to mine and with the lack of gas reserves in most countries, UCG provides the perfect alternative to produce gas from coal without the environmental impact. There are numerous advantages to extracting syngas from coal seams, when compared to conventional coal mining and to CSG (Coal Seam Gas).