This paper presents a method for retrofitting ESPs on coil tubing into existing subsea wells, not prepared for such an installation.

The results are an outcome of a feasibility study between Schlumberger Artificial Lift ltd–Aberdeen and Statoil R&D–Trondheim.

For IOR purposes on an existing subsea well there could be several methods of retrofitting artificial lift–a gas lift system, a jet pump or an ESP could potentially be installed, with individual benefits and drawbacks. The ESP could prevail in situations where it is undesirable to expose the well annulus to gas lift gas or jet pump power fluid and corresponding pressure. Also, it is deemed advantagous in some well cases to install an electric power cable on the seabed, rather than a pipeline as required for gas lift gas or jet pump power fluid.

The conclusion from this paper is that it is fully possible to retrofit a Coiled Tubing Deployed ESP into an existing subsea well, utilizing existing drilling and work over systems. The missing component is a CH–which is considered fully achievable, but will require designwork from the subsea manufacturing companies.

A Coiled Tubing Deployed ESP can be installed into an HXT system without large modifications to the existing subsea system, while as for a VXT completion the retrofit installation involves a Xmas Tree changeout.