I-SEP is a robust device needing little to no maintenance requirement. In applications where production of sand is involved, the internals of the unit can be coated or equipped with a layer of superior materials resistance to erosion, such as ceramics. In addition, Caltec has a design which allows the key elements to be housed inside a containment vessel as shown in figure 2. This feature allows easy inspection, non-intrusive monitoring of erosion and speedy change-out of the internals when needed. It is also worth noting that even erosion of the internals of I-SEP does not affect its structural or pressure holding integrity as the main pressure containment body is not exposed to fluid flow.
In terms of Caltec’s Wellcom technology there are significant reductions in terms of the operation cost related to the higher cost of spares such as replacement seals and bearings for multiphase pumps. Also, in many applications the cost of the cable supplying the power is significantly higher for MP pumps because of the higher power rating of the pump.
In some cases a separation vessel is needed upstream of the multiphase pump in order to reduce the level of flow fluctuation. This vessel adds further to the cost of the system.
The reliability in terms of mean time before failure (MTBF) of the multiphase pump system is relatively short compared to that for a single phase pump. This is primarily because the MP pumps have to handle multiphase flow and are therefore exposed to extreme flow fluctuations which are typical characteristics of the multiphase flow. This problem becomes more acute if sand is also present in the fluids.
Also see Benefits.