workover clamp for Drill Riser Pipe - DRP

Facing an increasing demand for more reliable ancillaries, BARDOT GROUP has developed and patented a smart workover clamp for Drill Riser Pipe (DRP) and umbilicals.
  • During workover operations on a wellhead, it is often require to lower one or several umbilical lines along with the DRP. It is necessary to maintain them tightened together to limit umbilicals catenary weight (and therefor tension) and excursions while operating. To do so, operators have recourse to clamps.

  • In an approach of weight limitation, these clamps are most of the time made of polymer. And even though they rely on a metallic bracket for tightening and securing, polymer is at some point the weak link in the tension chain. This is the root cause of slippage failure with unpleasant consequences.

  • BARDOT's concept has been targeting several aspect for the improvement of those clamps:
    - Reliability: the tension tightening chain no longer include polymer part, it is composed of an aramid strap and steel tensioning system
    - Simplicity: BARDOT's workover clamp is monobody, including a captive tightening screw. This means no loose part on the deck and no risk of component drop
    - Ease of use: thanks to a lightweight design (about 5 kg), this new clamp is easily operable by a single operator and is deployed very quickly
    - Tailor made: Workover clamp is available in various configurations (single or multiple umbilicals) and sizes.
    - Long-lasting: Clamp design is made for it to endure numerous mounting and unmounting cycles, seawater operations and long storage periods

    The workover clamp is composed of two aramid straps enclosed in a soft polyurethane body. The straps are tightened and released thanks to a set of also enclosed tensionning axles and captive single bolt.
    Casted in a single part, this design offers a very good resistance to multiple tightened and release cycles and corrosion.

  • As part of a qualification process, several mechanical tests have been carried out on the clamp to assess its fitness for purpose.
    The primary function of the clamp being to tighten the umbilical line on the riser, an axial load test is performed. On the tested configuration, axial load reaches up to 10 kN (about 1 metric ton).

    The clamp has also been tested for fatigue resistance against sliding and opening on a dedicated test bench. Test reached over 20 000 cycles and the clamp did not display any sign of damage or performance loss.

    Impact test has been performed to demonstrate the resistance of the clamp to dynamic loading. A 8 kJ energy is applied on it. The clamp experiences sliding and permanent strains but the umbilical does not exhibits damage nor is released from the riser.

    This versatile design is suitable for most riser/umbilical(s) clamping configuration, whether operations involve a casing (marine riser) or open sea. Its strong construction guarantees a reliability over years in most severe marine conditions.

BARDOT's workover clamp is patented under the publication number PCT/FR2015/051102