June 2009 Vol. 236 No. 6

Projects

Shell, Twister Announce New System Startup in Nigeria

Twister BV announced the successful startup of a new commercially operated Twister Supersonic Separator system June 12 in Nigeria.

The Twister gas processing module is used for dew-pointing 120 MMscfd of gas supplied as fuel gas to the 650MW Afam VI combined-cycle power plant, owned and operated by Shell Petroleum Development Company of Nigeria (SPDC). The Twister module incorporates six supersonic separator tubes together with a chemical-free Hydrate Separator.

Twister technology was selected for the onshore Okoloma Gas Plant due to its ability to achieve water and hydrocarbon dewpoint specification without the need for a glycol plant or a heat exchanger for inlet cooling. Twister systems are also being installed by Petrobras in Brazil and by Ecopetrol in Colombia.

In the late 1990s, Shell developed the basic principle of the Twister technology, which treats produced gas at supersonic velocities, extracting water and hydrocarbon liquids. Unlike conventional technologies, the process requires no chemicals and hence reduces exposure to hazardous gas emissions. It has no moving parts, permits near instant start-up and allows for considerable cost reduction, particularly for offshore installations. The Twister BV Company was established in 2001 to further advance and market the technology.

Further applications of Twister gas separation are being developed for C3+ recovery, sub-sea gas dew-pointing, flareless gas processing and sour gas processing, some of which are already in pilot stage.