All About Natural Gas

Natural gas as a source of energy is made up of four types of natural gas. It is called a fossil fuel, like coal and oil. Seventy to ninety percent of natural gas is composed of the natural gas methane. The remaining percent is made up of propane, butane, and ethane.

Natural gas is formed from bodies of dead animals buried under pressure in the earth for thousands of years. These decompose and are covered with rock and soil. The decomposed material goes deeper under the earth over time and meets hotter temperatures. The pressure and higher temperatures cause a breakdown of carbon bonds. Methane is formed. It is called thermogenic methane. Some can rise to the surface of the earth but be trapped in sedimentary basins made of rock. Holes must be drilled to reach these huge containers of natural gas.

These basins are found all over the world. Saudi Arabia, Alaska, and Venezuela are sites of natural gas drilling. Many states bordering the Gulf of Mexico contain many of these basins also. North Dakota, South Dakota and Montana have sources of natural gas too.

Companies drill near oil wells for natural gas, but sources near the surface are usually relatively small. The deposits of natural gas farther down in the earth are larger. The gas is paired with crude oil and made into what can be used for energy to heat homes and other everyday needs.

New technology is helping to extract natural gas from places previously thought to be inaccessible. Biogas is a type of gas formed when matter decomposes without oxygen present. This is called anaerobic decomposition. Sewage and animal matter found in landfills produce this type of gas. Biogas contains less methane but can be changed for use as an energy source.

Conventional gas deposits can be found about several thousand feet below the surface of the earth. Those found much deeper in the earth are called unconventional. They are usually found up to fifteen thousand feet below the surface. The cost of drilling that deep is high, so new technology is being developed.

Shale gas is also an unconventional gas. It cannot be drilled out in usual ways. Shale is a sedimentary rock built up in layers. Gas is trapped between impermeable sheets of the shale. Impermeable means that nothing can penetrate through it.

Hydraulic fracturing and horizontal drilling are two ways being used to try to retrieve this shale gas. Fracking involves splitting open the shale rock with a high pressure of steam and then keeping the openings apart by using pieces of glass, sand or silica. In attempting horizontal drilling to reach the gas trapped in the shale, men drill straight down and then horizontally into the gas trapped between the layers of shale.

Another process of retrieving gas from impermeable rock is acidizing. Hydrochloric acid is injected into the rock which will dissolve it and allow the gas to flow out. Coalbed methane is natural gas found along a seam of coal in the ground. This is called an unconventional gas too.

Leaks of natural gas were thought to be sacred many years ago by ancient civilizations. One of these leaks or seeps was near Mt. Parnassus in Delphi, Greece. A temple was established there with a priestess who said she could tell your future. It was called the 'Oracle of Delphi.'




A: Italy
B: United States
C: France
D: Greece

A: Methane
B: Carbon
C: Propane
D: Ethane

A: Biogas
B: Shale gas
C: Methane
D: Propane

A: Craters
B: Sedimentary basins
C: Gas caves
D: Gas basins

A: Drilling deep into the earth straight down
B: Shooting hot oil down into a gas well
C: Shooting hot steam down into the layers of shale
D: Using explosives to get at the gas supply

A: Contains no gas
B: Is permanently attached to something
C: Cannot be penetrated
D: Able to be drilled through








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