The most efficient method of transporting natural gas is through pipelines. Over the years, a complex transportation system has been developed, including a vast network of linepipe, compressor stations, valves and processing plants, to transport natural gas from where it originates to where it needs to be used – which can sometimes be several hundred miles apart.
Natural Gas Pipelines
The pipeline system is made up of typically large-diameter ERW pipe, between 24 and 36 inches, constructed especially for OCTG uses according to standards set by the American Petroleum Institute. Linepipe, which is often placed underground, is also treated with a type of epoxy coating to help prevent corrosion over time.
At its origin location, the natural gas is highly pressurized in order to minimize its volume and keep it moving quickly through the pipeline. In certain locations along the pipeline, usually at around 50 to 100 mile intervals, the natural gas will go through a compression station to ensure proper pressurization.
Maintaining the Pipeline
Sometimes in these same locations or in separate locations, metering stations are set up to keep accurate readings on the status of the pipeline system. The metering stations take regular measurements of the gas’s flow rate, pressure and temperature to ensure the safety of the linepipe, valves and everything in between.
Also at varying distances along the entire network of linepipe are valve locations, which allow for the release of pressure or gas from the ERW pipe. Additionally, these valves allow for the stoppage of gas flow within certain sections of linepipe. When a repair is needed, the gas flow will be shut off at two valves at opposing ends of the repair location so the pipe can be safely assessed and mended or replaced. After the repair is complete, the valves are used to resume the flow of gas through the pipeline.
The Final Leg
Once the gas reaches a processing plant, it is refined into the natural gas product used in homes and businesses. From the processing plant, the refined natural gas is transported through another network of linepipe to a local natural gas distributor, where it navigates yet another linepipe network to deliver the gas directly to where you need to use it.
[Photo by: Daniel X. O'Neil]
