The FPSO P-58 is located in a deepwater field and produces pre and post salt reservoirs. The artificial lift method selected for two post salt wells is the mudline ESP, where the equipment is installed in a submarine skid. The main advantage of this technology is to reduce intervention costs due to cheaper vessels. The concept was developed and tested in two Petrobras projects: Espadarte and Cascade-Chinook fields.

Some of the challenges are related to the need for horizontal positioning of the equipment, due to the dimensions involved. This impacted the method of assembly and installation of the ESP in the capsule, as well as design of the protectors. The Mudline ESP has two pumps powered electrically in parallel and arranged in series hydraulically. In this project, the equipment has evolved in relation to the previous installations, in particular the inclusion of chemical injection, access to hot stab and the capability to receive a flow homogenizer.

The system will begin operation in 2015 and it is expected that its runlife will be similar to the standard equipment installed in the well, but with lower intervention costs. Possible improvements for the next projects are the use of sensors on both pumps and the installation of the system with even simpler and cheaper vessels.

Since the assembly of the pump and the whole skid is done onshore, the process can have a better control and supervision. Also, an integration test is performed before the system installation, which allows a complete evaluation of its performance.

You can access this article if you purchase or spend a download.