Long-distance transport of natural gas is, due to the distance between the drilling site and the final consumption location, the economically most demanding link in natural gas transmission. It is possible to transport natural gas in two basic ways: by pipeline or in the form of liquefied gas in tankers.
Pipeline transport – Today, Europe is interlaced with a dense network of international gas pipelines, and their length is ever increasing. Operating pressures reach as high as 100 bars (10 MPa) in the newest pipelines, and pipe diameter often exceeds 1 m (e.g., almost400 km of pipelines with a diameter of 1.4 m are operated in the Czech Republic). Long-distance pipelines may cross dry land or be laid at the bottom of the sea. In this way, for example, natural gas from the North Sea and Africa is supplied to the European continent.
Tanker transport – This form of transport is used for the transport of natural gas across the sea over greater distances. Natural gas is liquefied in liquefying stations (liquefaction reduces the volume of natural case by about 600x; under atmospheric pressure, liquefied gas has a temperature of -161°C), where it is pumped into the tankers. At the target terminal, the gas is transferred to reservoirs, where it gradually evaporates and is supplied to the pipeline system.
Natural gas enters the domestic transport system from the long-distance transport system via substations. Regulation stations, which reduce gas pressure to values under which the national pipeline systems in the various countries are operated, are also part of the substations.
The national transmission system (predominantly high-pressure pipelines with pressure in excess of 4 MPa) transports natural gas to various direct customers (i.e., customers who offtake natural gas directly from the high-pressure transmission system) or to the distribution systems in the various regions and to towns and municipalities connected to the natural gas network.