Delivering Natural Gas to Your Home

Delivering Natural Gas to Your Home

By Dan McVey, Vice President & Chief Operating Officer – Gas Operations

The U.S. natural gas system uses more than 300,000 miles of pipelines, hundreds of storage facilities, and more than 50 import/export locations. This extensive network can transport natural gas to almost any point in the country, quickly and affordably. Here’s more about what it takes to bring natural gas to your home.

Gathering

Pipelines are used to transport natural gas from the wellhead to a central location where processing facilities remove liquids and other impurities. The natural gas can then be compressed to achieve a higher pressure and is then ready to go into the transmission pipeline system.

Transmission

An elaborate network of pipelines and equipment transmit natural gas to areas of high demand. These transmission pipelines form a complex highway with natural gas traveling at an extremely high pressure.

Transmission pipelines vary in size and function. There are two major types:

• Intrastate pipelines carry gas from processing plants to distribution centers within one state.

• Interstate pipelines carry gas from processing plants to distribution centers between states. Though technically similar, intrastate and interstate pipelines are often subject to different regulations.

The transmission system includes infrastructure that guides and controls the flow of natural gas:

• Compressor stations use turbines, engines or electric motors to maintain high pressure as the natural gas moves through transmission pipelines.

• Metering stations measure the flow of natural gas so that it can be monitored and managed as it moves.

• Valves and regulators control the flow of gas in the pipelines.

Storage

While moving through transmission pipelines some natural gas is injected into underground storage facilities. Storage is critical to maintaining adequate supplies. Excess natural gas delivered during the summer months is stored in base-load facilities to ensure adequate supply and price control during the heating season.

Peak-load storage facilities help meet short-term supply interruptions or demand increases. These facilities can deliver smaller amounts of gas more quickly than baseload units and are easily replenished.

There are three main types of underground storage facilities:

• Depleted gas reservoirs are geological formations that no longer contain recoverable natural gas.

• Aquifers are permeable, water-containing rock formations reconditioned to store natural gas.

• Salt caverns refitted for storing peak-load natural gas.

Distribution

Distribution is the final leg in the journey. The natural gas pressure is lowered with regulator stations at the transmission delivery point (city gate) prior to distribution. Because natural gas is odorless, mercaptan is added to make leak detection easier. Mercaptan smells like rotten eggs.

Local distribution companies deliver gas to end-users at various points along the transmission system. These companies may be investor-owned or member owned gas systems like your Cooperative. Through this process, smaller volumes of gas at much lower pressure are transmitted through smaller pipelines to the meter at your house.

State utility commissions regulate local distribution companies, as well as distribution lines and intrastate pipelines. Some states allow gas marketers to provide for the supply of natural gas, although local distribution companies typically oversee and manage the delivery infrastructure.