Definition - What does Transmission Line mean?
Transmission Line also referred to as a trunk line at times, is a pipeline which is used to transport crude oil, natural gas and petroleum products across countries or within states. These pipelines are a set of large diameter carbon steel pipelines which carry the petroleum products across countries or borders. Transmission lines are broadly classified into two types:
- Interstate Pipelines – These pipelines transfer petroleum (Crude oil, Natural gas and Products) across country borders. They also called Cross country pipelines.
- Intrastate Pipelines - These pipelines transfer petroleum (Crude oil, Natural gas and Products) across various states in a country.
Petropedia explains Transmission Line
Transmission Lines are one of the safest and most effective ways of transporting crude oil, natural gas and petroleum products between border sharing nations and states. The industry jargon for pipelines vary with respect to the oil and gas sectors viz upstream, midstream and downstream.
In the upstream sector of the oil and gas industry, the pipelines which carry crude oil and natural gas from the wellhead to the processing plants are small diameter pipelines called gathering systems. Once crude oil and natural gas are processed and impurities are removed, they are sent to trade in the market of the countries or states which need them via trunk pipelines (intrastate or interstate pipelines). The crude oil is then transported to the respective countries or the state refineries for further processing via large diameter trunk pipelines called transmission lines. Once the Petroleum products are produced, they are further transported to various demand centers within the country either by intrastate pipelines, rail or road network. To carry the products further to the customers, small diameter pipelines called spur lines are connected to the trunk lines which carry the products further to the densely populated demographic regions.
The trunk pipelines are large diameter carbon steel pipelines with diameters ranging from 20 inches to 48 inches or more and cover more than 2000 km distances.
The diagram below represents the flow of hydrocarbons from upstream to midstream to downstream and the notations of pipelines.