Reactive Flex Joint

The Reactive Flex Joint (RFJ) is developed by FMC in cooperation with Statoil to reduce fatigue on wellheads. The flexjoint is landed on the BOP, and is designed to provide a counter-acting force to the bending moment applied on the wellhead by the riser load on the BOP.

The counter-acting force is generated by the movement of the riser itself, generating a bending moment which increases with the riser angle. Innova was challenged with the design of a hydraulic system for transferring the riser movement into hydraulic force to the cylinders. This involved functional analysis of the RFJ hydraulic system; hydraulic system design; design of a fluid converter system between water-based and mineral-based fluid; and manufacture and testing of the complete system, including interface panel and accumulator bank. A number of special components had to be purpose-designed for the system.

The system was designed in close cooperation with Client, successfully tested at Innova’s workshop and subsequently installed and tested at on the RFJ.