New Equipment and Methods for Flying Lead Installation

From 2018 and through 2020 Udeco has performed a number of Flying Lead jobs. These jobs have led to development of new equipment and methods for deployment and installation of HFL’s and EFL’s / OFL’s.

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From 2018 and through 2020 Udeco has performed a number of Flying Lead jobs. These jobs have led to development of new equipment and methods for deployment and installation of HFL’s and EFL’s/ OFL’s.

For HFL’s this resulted in the development of dual parking stands that permit two or even more HFL’s to be deployed in the same installation basket. This reduces the amount of deployment basket needed, and also potentially reduce offshore time consumption relating to the deploymentand recovery of installation baskets.

Due to the high number of EFL’ and OFL’s that Udeco had to prepare and load into deployment basket the last years, equipment and methods that permit Udeco to perform this efficiently have been developed. In 2016 the Ufist Ball Fist system was developed in order to replace rope type monkey fist. An Ufist ball fist is attached to a flying lead in approx. 1 minute. Small fists are used on EFL/OFL cables, large fists are used on HFL’s. The ones used on HFL are attached using a 50mm wide webbing strap. On HFL’s with spiral guard the straps will not come indirect contact with the hydraulic hoses during ROV handling of the HFL.

In 2017 cable strapping plates were developed, these plates, 4 off installed in each EFL / OFL flying lead compartment, secures the cable in the basket. They replace the standard method used which is to secure the cable with nipped tie-wraps. With these plates all cable layers are secured at four locations, and they eliminate the risk relating to a possible tie-wrap which has not been nipped (forgotten / missed). The latter could potentially damage the cable during pull out from the basket. Furthermore, environmentally it is preferred that no plastic tie-wraps are left on the seabed after the pull-out of the flying lead. Finally, using the strapping plates are considerably faster than using tie-wraps. The strapping plates also make the packing of the flying lead compartment easier and faster than what is the case without strapping plates.

Parking receptacles used for parking electrical, optical and mono hydraulic couplers have been developed for a number connector sizes. Based on risk considerations Udeco is of the opinion that the connectors shall be protected when parked in the basket. Beside mechanical protection, connectors should also be protected from exposure to debris, mud, sand and silt during basket transport, handling, deployment, landing on the seabed and when other cable sections are pulled out from the basket. In addition to provide protection, the Udeco style parking receptacles are designed such that they are fast to install, reposition or change out in the basket. They also includes a feature that prevent the connector from unintentionally come out of the parking receptacle due to wave action or similar. In 2020 one client had a need for a ROV removable temporary protector for some electrical connectors (see picture). Udeco therefore modified a parking receptacle design such that when the ROV retrieved the connector from the parking receptacle in the basket, part of the receptacle remain attached to the connector and act as a protector (mechanical +debris). The protector is removed by the ROV prior to connecting the connector. The protector does not include any metallic parts that may cause a possible galvanic reaction with the connector parts if the connector including protector is left temporarily unconnected on the seabed or subsea structure.

The last few years the EFL’s and OFL’s sometimes comes with three or four legs / tails. If these legs are short it becomes a challenge to retrieve them one and one from the basket and bring them over to the connection location. In order to bring several connectors and cable tails/legs over to a connection location at the same time and to ensure that all connectors are secured and protected during the pull out operation, the FLP Box was developed in 2020 (see picture). The Flying Lead Parking / Positioning Box, FLP Box, permit up to three flying lead legs with connectors to be pulled from the installation basket. The connectors are parked in the Udeco style receptacles included in the box. Using two FLP Boxes would allow one to handle cables with six legs (or more if some of thelegs are long). The weight of the FLP Box is 50kg in seawater. The ROV pull the FLP Box from the installation basket and fly it together with the flying lead cable over to the connection location. Here the box which has a low centre of gravity is either placed onto the subsea structure or on the seabed. Then one and one connector is pulled from the parking receptacle on the FLP box and connected to the subsea unit.

The FLP Box can also be used as a temporary local parking location for connectors that have to be disconnected and parked during and intervention or workover operation.