Subsea boosting has today achieved a significant track record and it has been recognized by major oil companies as an important part of enhanced drainage strategies. For gas fields compression is the only viable means of artificial lift and subsea compressions offers many advantages over conventional topside compression such as increased ultimate recovery. The advantages of subsea compression increase with increasing tie-back distance.

Particular features and benefits of subsea multiphase or wet gas compression are discussed in general and the particular experience with a subsea wet gas compression system now in operation at the Gullfaks field on the Norwegian continental shelf is presented.

Commissioning of the Gullfaks Subsea Wet Gas Compression System started in 2015. The system ran for one month but had to be taken out of operation for almost two years due to umbilical leakage. The system was restarted in 2017 and has been running successfully ever since, boosting wet gas and increasing the production from several wells. The system flexibility is exploited in a more extended way then ever expected during the project phase, and allows the operator to take advantage of many opportunities including increased oil recovery, and kicking off dead wells and enabling stable well back-pressure. The fundamental benefits of subsea compression are now demonstrated.