Natural gas is a fossil fuel primarily composed of methane that forms naturally over millions of years. It originates from the decomposition of organic matter-mainly plants and animals-that accumulated in sedimentary environments like seabeds, swamps, and riverbeds. Over time, layers of sediment bury this organic material, subjecting it to intense heat and pressure deep within the Earth's crust. This process, called thermal maturation, chemically transforms the organic matter into hydrocarbons, including natural gas, oil, or coal depending on the conditions. Natural gas typically forms at higher temperatures and pressures and deeper underground than oil
. Once formed, natural gas migrates through porous rock layers until it is trapped beneath impermeable rock formations called cap rocks, creating reservoirs that can be tapped for extraction. These reservoirs are often found in rock formations deep below the Earth's surface and are frequently located near oil deposits. Natural gas can also be found in coal beds and shale formations
. Extraction methods include drilling wells into these underground reservoirs. Conventional extraction involves drilling into permeable rock formations to release the gas, while hydraulic fracturing ("fracking") is used to create fractures in less permeable shale rock to free trapped gas. After extraction, natural gas is processed to remove impurities and natural gas liquids before being transported via pipelines or liquefied for shipping
. Major natural gas reserves exist worldwide, with significant deposits in countries such as Russia, Iran, Qatar, the United States, Saudi Arabia, and Iraq. In the U.S., key natural gas-producing states include Texas, Pennsylvania, Oklahoma, Wyoming, and Louisiana
. In summary, natural gas comes from ancient organic matter transformed by heat and pressure deep underground, trapped in rock formations, and extracted through drilling and fracturing techniques
