GEA (Düsseldorf, Germany; www.gea.com) has designed, manufactured and delivered a gas-jet compressor system for an offshore platform in the North Sea consisting of a jet pump (ejector) with a total length of about 4.5 m and silencers to reduce the sound pressure level. At a newly drilled well natural gas is available with a pressure of up to 600 bars. The gas pressure decreases in the course of exploitation of the gas field. At a defined gas pressure, the gas delivery rate is so low that the mechanical compressor is no longer economical.
Gas jet compressors are perfect to increase the natural gas pressure and to allow extending the use of the installed mechanical compressors. In this way, the gas field life is prolonged. The system compresses a low-pressure natural gas (8 barg) by using a high-pressure natural gas (90 barg) to an intermediate gas pressure (12 barg). GEA managed to increase its portfolio by designing the ejector-body for 137 barg – and on the motive side for 213 barg.
The material of construction is corrosion resistant and corrosion tested Duplex-stainless steel, which is coated with sprayed Aluminum. Ejectors are reliable in operation at low operating costs. They are almost maintenance-free because they are of simple construction, having no moving parts. Almost any vacuum duty can be accommodated including large suction flows.