Electric Technology
FMC Technologies leads the industry in subsea all-electric technology, with field-proven subsea experience operating multiple chokes and manifolds on installed production wells since 2001.

An electric-actuated subsea system enables precise valve control, providing optimum flow and production. For advanced applications like intervention, workover and processing, FMC Technologies‘ electric controls system allows for increased response time and advanced sequence control. It also reduces the possibility of disconnects. Our electric technology is well suited for a large number of subsea applications:
•Long-distance tiebacks
•Production and water-injection wells
•Chokes
•Manifold valves
•Valve actuator retrofits
•Process control valves for subsea separation
•Anti-surge valves for subsea gas compression

All-electric systems provide more rapid and accurate equipment performance and eliminate the need for larger and more expensive hydraulic and electro-hydraulic umbilicals. The environmental benefits are equally compelling, as the need for and disposal of hydraulic fluids is eliminated.

Systems & Products

eActuator
FMC Technologieshas supplied over 120 all-electric subsea systems in commercial applications to customers. This includes a substaintial amount of all-electric actuators and communication units.

An electric choke actuator system, consisting of electric choke controls and a sand detection system, was retrofitted to StatoilHydro’s Statfjord project in 2001. The system was developed for easy integration into existing subsea control system architectures, with no impact on communication quality and a minor increase in power consumption. To avoid loss of production, the new system was designed so it could be installed without having to retrieve the SCMs (Subsea Control Modules) or choke bridges.

All subsea equipment was designed for installation with ROV support. The choke actuators easily adapt to any ROV interface.

Due to the success of this system, FMC Technologies was selected by StatoilHydro to develop an all-electric subsea tree for another field, representing a significant milestone in the evolution of all-electric technology.

Electric Manifold
Actuator systems also can be used to operate manifold and pipeline sled valves. Electric manifold valve control is especially attractive in systems where control modules can be eliminated from the manifold. The technology offers precise position control and can be applied subsea without a hydraulic umbilical, providing huge cost-saving potential.

Basing the system on local energy storage with rechargeable batteries enables cost-efficient retrofit scenarios like those of Statoil’s Norne system in the North Sea. In the Norne system, electrical operation replaces manually and hydraulically operated valves and chokes.

This modification results in better response times for the chokes, enables free routing of existing and new infield wells and liberates hydraulic lines in an existing umbilical. Capital expenditures for the field extension are reduced significantly.

eSCM
The electric Subsea Control Module (eSCM) governs the electric control system. It comprises traditional SEM technology as in ordinary SCMs for communication, power conditioning and data acquisition. It also houses the Li-Ion Battery Packs and the Battery Management System (BMS).

Li-Ion Electric Technology
Lithium-ion (Li-ion) batteries are largely produced for high-tech professional applications and are easily integrated due to their small size. The technology has proven its high reliability through many years of subsea operation as well as substantial operational experience from other similar critical applications. Li-ion batteries provide exceptionally long life and maintenance free technology, allowing for total lower life-cycle cost.
FMC Technologies have developed a Battery Management System (BMS) dedicated to the application. Features in this system allow users to manage: power flow in the systems; charging strategies; monitoring of voltage, current and temperature; cell balancing and redundancy switching with a CAN interface.

For more information:
http://fmctechnologies.com/en/SubseaSystems/Technologies/SubseaProductionSystems/ElectricTechnology.aspx