Faster installation for offshore chocking system

Edited by the Engineeringtalk editorial team Jan 6, 2005

The SmartShim cast-in-situ chocking system from Furmanite has undergone a new development which slashes installation time on offshore platforms, adds a high degree of control and flexibility.

The SmartShim cast-in-situ chocking system from Furmanite has undergone a new development which slashes installation time on offshore platforms, adds a high degree of control and flexibility, and makes the service even more efficient with valuable benefits to operators.

This has already been demonstrated on one North Sea platform, where gaps as large as 750mm the largest undertaken to date were "SmartShimmed" with significant time efficiencies.

The latest improvements to the SmartShim system are the result of a new pump skid developed by Furmanite, which fully automates mixing and pumping of the resin on-site a key element in installing SmartShim for maximum precision and control, and a speedier process.

SmartShim, an award-winning patented innovation, is designed to prevent costly damage to conductors or caissons created when the lateral force of wave movement causes them to impact against the conductor guides resulting in fatigue or even fracturing.

The SmartShim slips are manufactured from a PVC-proofed nylon and are filled with a specialist Furmanite-developed polyurethane resin and cast-in-situ, thereby forming to fit the gap between conductor and guides precisely, whatever the dimensions.

Importantly, SmartShim is engineered with sufficient elasticity to absorb the wave energy effects, while holding the riser or caisson firmly in place within the guides.

It is in filling and casting SmartShim on-site that the new development is proving so valuable.

For instance, removing the need to hand-mix the resin on-site before starting to fill the SmartShim slips saves significant time.

It also means the process is more environmentally friendly.

Precision and elimination of human error in the ratio and mixing process are further benefits of the new system, in which the whole process is monitored from a control panel by a trained Furmanite operator.

"Moreover, because (apart from one short length of hose) the pumps and hoses contain only unmixed components, the process can be stopped and started again if necessary without concerns over the resin having begun to cure in the hoses and pump", Furmanite's Materials Technology Manager Dominic Dean adds.

"This provides maximum flexibility and minimum time demands, particularly valuable offshore where setting up and cleaning down time can be reduced from every day to once a trip".

The benefits of the new improvements were exemplified in the installation of SmartShims on some ten 20in nominal bore risers on one North Sea platform, situated at the +10m elevation guides.

Damage was being caused at the guide location due to excessive movement at the wellheads and the existing centralisers not being designed to absorb any shock loading.

"The new pump skid enabled us to install the SmartShims quickly and efficiently", Furmanite Business Manager Graham McKay commented.

"Despite the large gaps being chocked (750mm), installation time was reduced to just two days per conductor including curing time as a result of the new developments, as opposed to 4-5 days previously".

A full scale workshop trial was undertaken in advance of this project, including a mock-up of the conductor and guide built in the workshop to facilitate load tests and prove the system worked before going offshore.

Following successful installation a further four risers are now due to be chocked on the platform using SmartShim.