Natural gases are naturally occurring mixture of hydrocarbons which are made up of methane with varying quantities of higher alkanes and at times smaller percentage of helium, hydrogen sulfide, nitrogen and carbon dioxide. It is the fossil fuel which is used as a source of energy for generating electricity, cooking, heating, and car fuel among other uses. Natural gas is formed when decomposing plant and animal remains are exposed to intense pressure and heat for millions of years under the earth’s surface.
Natural gas was accidentally discovered in ancient China while they were drilling for brines. The Chinese used the gas to boil the brine and produce salt. The Chinese living in Ziliujing District created a crude pipeline using bamboo pipes and piped it from its source to where they were extracting salt from brine. The first industrial extraction process began in 1825 in Fredonia, New York and by 2009 about 8% of the estimated natural gas content had been extracted.
How Is Natural Gas Formed?
Millions of years ago, the animals and plant remains accumulated together forming thick layers of decomposing matter mixed with silt and sand. These layers were buried under rocks, mud, and sand. They were exposed to intense pressure and heat, and with time they turned into petroleum, coal and natural gas. The natural gas moved to some spaces and cracks between rocks and in some places the gas occurred in sandstones and shale among other sedimentary rocks.
Sources of Natural Gas
1) Natural Gas
During the nineteenth century, natural gas was obtained as the by-product of oil production. Some natural gasses were released from the solution as it underwent pressure reduction during the extraction process. Disposing of the unwanted natural gas during the nineteenth and early twentieth century was a problem especially for active oil fields; therefore they were burned off. Currently, it is pumped back to the reservoir using injection wells as it waits to help repressurize the oil extraction process and improve the extraction rates or wait for future markets. In nations with high demands, it is piped from the well-sites to the end users.
2) Shale Gas
The shale gas is extracted from shales. Since the matrix permeability of shale is too low for gas to flow in economic content, the wells depend on natural fractures that allow the gas to flow. Earlier mining companies depended on natural fractures, but all the modern day wells have artificial fractures which they make using hydraulic fracturing. In countries like the United States and Canada, shale gas has become the primary source of natural gas since 2000. Due to the success of shale natural gas in the United States, other nations like South Africa, Poland, and China have begun exploring shale gas extraction.
Other Sources of Natural Gas
Town gas is created by the destructive distillation process of coal, and it contains numerous gases like methane, carbon monoxide, and hydrogen among other hydrocarbons which are used as natural gases. Other sources include methane hydrates, biogas, and landfill gas. Biogas is the methane-rich gases released by the anaerobic decaying process of biomass. Landfill gas is produced when the waste in the landfill sites decompose.