unconventional gas

Unconventional gas refers to natural gas found in geologic formations that differ from conventional traps. These include "tight" sandstones with low permeability, shales, and coal seams. Large quantities of gas are also trapped in methane hydrates and geopressured waters.1

Exploiting unconventional gas is generally more expensive and yields slower production rates than conventional gas due to current technology and economic conditions. However, advancements in technology, particularly horizontal drilling and hydraulic fracturing (fracking), have made the extraction of tight gas and shale gas economically viable. Fracking involves injecting fluid at high pressure into underground rock to create fissures, releasing trapped gas. While this has significantly increased natural gas supplies, it has also raised environmental concerns, including potential groundwater contamination and seismic activity.123