ITP Field Joint

The offshore FJ operations consist of connecting the PiP subassemblies to each other on a laybarge in order to obtain the pipeline which is laid on the seabed.

The mobilization of a laybarge is expensive (mobilization of heavy-duty equipment and personnel) which makes the reduction of the cycle time (the sequential operations performed to join 2 subassemblies) of essence to minimize installation costs.

Contrary to conventional PiP that require the weld performance of both the inner and outer pipes, ITP has developed a field joint design based on a unique offshore weld that saves considerable laybarge time: the ITP design allows lay rates that can be compared to those of bare pipes.

ITP has designed an insulated pipe-in-pipe sleeve that is slid over the offshore weld to ensure both thermal and mechanical continuity at the Field Joint.

This technique which has been successfully implemented on both S-lay and J-lay projects has an extensive Track of Record.

ITP pipeline in overbend, S-lay firing line (Forvie North Sea project)

Advantages of the ITP FJ

- Reduction of offshore cycle times for J-lay and S-lay.

- Simplification of the offshore pipe connection activity (no fit up & welding of the outer pipe offshore).

- No half-shells required and its associated welds controls.

- The sleeve provides an efficient insulation at the FJ and a long cooldown time.

- The ITP Field Jointing operations mobilize only 1 station in the firing line; thus more stations can be dedicated to the inner pipe weld.

- The FJ acts as a buckle restrictor.

- The InTerPipe welds (welds connecting the outer to the inner pipe) act as true buckle arrestors and water stops.

Recent offshore layrates

- TOTAL FORVIE: up to 2.9km/day (1.8mi/day) (Double Joints, 15”/17” PIP, S-laid, trenched and buried, 95°C).

- TOTAL DUNBAR II: up to 1.1km/day (0.7mi/day) (Simple Joints, CRA lined, 16”/18.6” PIP, S-laid, surface laid, 100°C).

- TOTAL ROSA: up to 2.5km/day (1.6mi/day) (Quad Joints, 9”/12” PIP, J-laid, 70°C).

ITP Field Joint sleeve in J-lay tower (Rosa project)