Natural gas is found beneath the earth's crust where gases have been formed over millions of years from decomposing plant and animal matter. Natural gas reservoirs are frequently (but not always) found above petroleum reserves.

 

A gas well is a hole drilled through rock through which pressurized natural gas rises to the surface and is collected. The gas is processed to remove contaminants such as water, hydrogen sulfide and carbon dioxide. Once the gas is clean, it is shipped via transmission lines to distribution companies, including Terasen Gas. We then odourize the gas for safety reasons and either sell it to our customers or store it for later use.

Liquefied natural gas is natural gas cooled until it condenses into a clear liquid. We store LNG at minus 162 degrees Celsius (-260 degrees Fahrenheit). At this temperature LNG takes up far less space — about 1/600th of its original volume as a gas. The liquefied fuel is not flammable or explosive, so we can store it safely at atmospheric pressure in insulated tanks built to withstand its cold temperature. Natural gas is only flammable in its gaseous state when the gas-to-air mixture is between five and 15 per cent.

 

When LNG needs to be converted for normal use, we pump it from the tank, pressurize it to pipeline pressure and "warm" it back into gas. Storing natural gas as a liquid is a safe and reliable process that has been used in North America without incident for over 40 years.