Process Diagram & Description

The capacity of the Frigg UK Terminal at St Fergus is:

  • nominally 36 MMscm/d (through three gas processing trains)
  • liquids production of 35 kbpd 

Gas processing is by JT valves and/or turbo expander. Liquids handling is by two de-ethaniser trains.

The gas trains are identical and designed for parallel operation. They feature the following operations:

  • liquids separation (inlet scrubber)
  • gas dehydration
  • NGL recovery
  • sales gas re-heating 

The liquids trains are built for parallel operation, and feature the following operations:

  • liquid dehydration
  • de-ethanisation
  • associated off-gas compression 

The pressure and temperature of the process facilities are a function of the operating mode. This can be either high or low liquids production, depending on the prevailing economics.

The following diagram shows one of the three gas processing trains.

Please click the image for a larger version.