Unit 220 – Feed Gas Separation

The flow of production fluids through the subsea flowlines ranges between from 403 MMscfd to 458.9 MMscfd at a pressure of 80 bara and temperatures between 20 – 90 °C. The fluids are sent to the Feed Gas Inlet Separator (V-220001), a vertical two-phase separator vessel. The main bulk of the separated gas is sent to Mercury Removal (Unit 225), whilst portion is sent to the Fuel Gas System (Unit 340) for start-up purposes. The separated liquids are sent to Condensate Stabilization (Unit 240). On the other hand, the Feed Gas Inlet Separator is also designed to hold up a slug volume of 30 m3 in order to protect the downstream facilities.
A Feed Gas Inlet Separator Heater (E-220002) is provided at the bottom of the Feed Gas Inlet Separator and is designed such that the tube side of heater is always immersed in liquid. Hot water is used as a heating medium for the Feed Gas Inlet Separator Heater. Feed Gas Cooler (E-220001A/B) serves a dual function as a cooler during normal operation to reduce the gas temperature and as a heater during start-up. The gas outlet temperature from the Feed Gas Cooler (E-220001A/B) is maintained at 35°C in order to meet the AGRU feed gas temperature in all operation modes with the exception of start-up
A Test Separator (V-220002) is provided to test the performance of any individual well. In addition, the Test Separator is 50% by volume of the Feed Gas Inlet Separator; and may also function as a backup separator. Moreover, Test Separator is provided with a sand jetting system in the water section for removing sand associated with the incoming production fluid expected at the later stage of production.