Pipelines
Pipelines are used to transport large volumes of oil as well as gas over long distances at different stages of the oil and gas production and distribution.

• Well to manifold or gathering system for subsea and onshore wells.
• Manifold to process plant for sub sea wells
• Process plant to refinery or gas treatment plant
• Refinery or gas treatment plant to local distribution terminals

Pipelines between wellhead and manifold or gathering system and between manifold/wellhead and process plant will in most cases needs to be able to transport multiphase (gas, condensate and liquids) well streams.

A pipeline transportation system will comprise:

• Compressors and pumps
• Valve stations
• Pig receiver and launch facilities. The pig is a device sent through the pipeline, driven by the pipe flow, for cleaning or inspecting the pipeline.
• Pipeline SCADA (Supervisory Control And Data Acquisition) system and pipeline management system to control and operate the pipeline.

Gas pipeline – To keep the required gas flow one or more compressor stations are needed. If the starting pressure is not sufficient to overcome internal friction such that the required flow is maintained, additional compressor stations needs to be installed along the pipeline.

The composition of the gas will in addition to methane (CH₄), that is lighter than air also contain heavier hydrocarbons such as propane (C₃H₈) and butane (C₄H₁₀) that during a leak would sink and create potential volumes of combustible mixtures. To reduce the impact of a potential leak, valves are required along the pipeline to be alble to segregate the leaking section from the rest of the pipelinee uch that the volumes of gas that could be be released are limited.

Liquid (oil) pipeline – To keep the required flow, pump stations are needed. The pumping capacity is in particular needed when the pipeline is routed through up hill landscapes to overcome the forces from the specific gravity of the liquids. Likewise pressure reducing turbines may be needed to overcome the gravitational forces downhill. Valves are installed to controle and limit the volumes released during a potential leak.