Natural Gas Liquids Overview

Photo: Øyvind Hagen/Statoil

Natural gas, sourced from gas wells or associated with crude oil, provides a rich source of ethane and liquefied petroleum gas (LPG*) for use as petrochemical feed stocks and liquid fuels. Processing of natural gas is typically required at least to meet pipeline hydrocarbon dewpoint specifications. Deeper processing to recover natural gas liquids (NGL**) components can often be justified based on their higher value as separate products compared with their value as sales gas. As processing margins vary, Costain appreciates flexibility is vital in design of NGL recovery facilities.

Costain is a process contractor with a long track record in the design and supply of low temperature gas processing plants, developing and optimising process designs to ensure highly efficient use of available refrigeration, offering outstanding liquids recovery whilst minimising power consumption. 

Costain’s patented technology portfolio includes state of the art, highly efficient processes, achieving propane and ethane recoveries in excess of 95%, in addition to offering lower capital and operating costs. Processes are customised to suit a client’s particular feedstock, product requirements and to minimise energy costs. Systematic design techniques and cost-benefit analysis are employed to optimise plant design and minimise life cycle costs.

Costain offers a comprehensive capability ranging from provision of a basic design package and technology licensing agreement, through to detailed engineering, procurement and construction management services.

Costain has designed and constructed major gas processing facilities for NGL recovery and fractionation and has developed many concepts for high NGL recovery, including a high propane recovery process with dual turbo-expanders, used to process 1600 MMscfd of natural gas.

* Liquefied petroleum gas (LPG) is a mixture of hydrocarbon gases used as a fuel and consists mainly of propane and butane.

** Natural gas liquids (NGL) is a mixture of liquid hydrocarbons found in association with natural gas. NGL include ethane, propane, butane and condensate.