In the 1920s, natural gas was discovered in the United States’ Great Plains. Upon that discovery, the rate of pipeline construction increased sharply to accommodate a growing need for natural gas as a heating fuel in large Midwestern cities.
Since then, the United States has developed a sprawling natural gas pipeline network, composed of over 300,000 miles of transmission pipelines, and more than 210 separate natural gas pipeline systems. This large system can transport natural gas to and from virtually any location in the lower 48 states through both interstate and intrastate pipelines.
During the transportation process, natural gas passes through many physical transfers and processing steps. Natural gas is sourced from a producing well or field, and then sent through three main natural gas pipeline types:
- Gathering pipelines are small-diameter pipelines that move natural gas from a wellhead, to either a mainline transmission grid, or processing plant, depending on the quality of the initial product. Processing plants separate hydrocarbon gas liquids, nonhydrocarbon gases, and water from the natural gas before it is sent to a transmission system.
- Transmission pipelines are wide-diameter, long-distance pipelines that transport natural gas from the producing and processing areas to storage facilities and distribution centers. A number of compression, or pumping stations line transmission pipelines. These stations contain one or more compressor units that receive the transmission flow from a previous station, and increase the rate and pressure of flow to sustain the movement of the gas along the multiple pipelines it needs to travel to reach markets and consumers.
- Distribution pipelines, or local distribution lines, move gas closer to cities and residential areas, where local distribution companies reduce the pressure of the natural gas to a level that is suitable for residences and commercial establishments. Smaller service lines travel to the homes, businesses, or industrial areas in need of natural gas.