Topside debottlenecking to improve water handling capacity and manage severe slugging issues

The DPS was modelled topside at a field centre to manage severe slugging and improve the liquid handling capacity. The DPS System was designed to be skid based and loaded using the platform crane.

Challenge

The used of unmanned platform is one of the new options within the oil industry.  This approach put some new demands on the equipment to be used, especially on the pressure ratings since all process exposed equipment must sustain the well shut in pressure. Pressure above 300 bar is not unusual and combined with relative high production rate the conventional process equipment can be huge and very heavy.

Solution

The DPS system is designed to withstand water depth of more than 3000 meters having the same design as an installation in 100 meters water depth. Again, a benefit using pipes.

If the pressure is external or internal is in principle similar and the result in the topside case was applying a subsea design topside. The operational weight less than 25% compared to a conventional separator and required footprint much smaller since the length of the conventional separator was very long since the separator diameter must be reduced (pressure/wall thickness related).

Benefit

Weight a space savings is a good argument.

Less hydrocarbon volume topside compared to a conventional separator influence the fire water design (deluge system).

Another benefit was an optional IOR potential. The original design is based on a separate gas pipeline to the host and a multiphase pump and separate liquid pipeline to host. If an additional pipeline for separated water is installed along with two single phase pumps for further pumping to host the operational pressure at the well head platform can be lowered hence increase in production from the reservoir. The use of single-phase pumps requires less energy and provide higher performance and reliability.