I've not used them but a collegue has on Captain, and put an SPE presentation together. I'll see what he says, but from memory they're a lot more tolerant than ESPs are to gas, but as they operate at a higher rpm, less tolerant of solids. However, Captain is a fixed platform, not subsea...
Framo's pump is a subsea multiphase pump, not a downhole pump. It can be a good alternative to installing artificial lift in subsea wells, if you put at the wellhead (or subsea manifold) to boost the produced fluids along the flowline and up the riser to the host facility. This means the FWHP can be reduced, which means the FBHP can be reduced, increasing the drawdown and increasing production. The other advantage with this type of solution as its easier to workover a subsea Framo pump with a DSV than a downhole ESP or HSP with a semi, although this is less of an adavantage against gas lift, where you can use a DSV to move your gas lift vlaves around. A NODAL analysis would give you the answers.
Having spoken with my pal who worked on Captain, it seems that all but one of the HSPs on Captain were subsea, with no pump failures after about three years when he left he project (one well failed due to non pump reasons) and with availabilities up at around 100%. They've pumped up to 75% gas continously and even managed 100% gas intermittently without gas locking. Issues include the surface equipment for the power fluid, large size of the completion with one string for the power fluid and one for the produced fluids (i.e you need 9-5/8" through the reservoir), but other advanteges in additon to the gas handling capbailities and the lack or subsea electrical connections is the fact that he pump iself is pretty short- you won't be handling 180ft of pump stages or something stupid.
So if you've got a high GOR crude, they seem to be a real alternative to ESPs, but as an alternative to gas lift, I'd guess the real advantage is no need for a gas compressor, and that's about it.
Wier Pumps make them, and can give you a lot more information and engineering assistance.
Thanks for all the replies. I have contacted Weir pumps in Glasgow (Scotland. Hopefully they will be sending me more details. For those interested, below is what I have found so far.
Article
SPE88837 – A case Study in the Design and Execution of Subsea Production Development Wells in the Captain Field. (June 2004 SPE Drilling & Completion)
I will _strongly_ recommend that you also talk to FRAMO. This is only based on my personal experience with both of the two companies mentined (Weir and Framo)
