Two dynamic umbilicals in a tethered lazy wave configuration were required to be wet parked in an ultra-deep environment with a water depth in excess of 2900m.
The close proximity to the pre-installed mooring lines, along with the in-place configuration requirements (seabed connection location, short seabed tether length, quantity of distribution buoyancy modules) made the design of a viable wet park configuration particularly challenging.
Strong current was also a major driving factor. The speed and dominant directionality influences the umbilical hump excursion, the stability of the umbilical and potential interference between the umbilicals and mooring lines. Several different routes were assessed to overcome the key problems as part of the wet park engineering solutions.
The installation of these umbilicals into their wet park configurations similarly presents a significant engineering undertaking.
An innovative and unconventional solution was chosen for the design of the wet park. The configuration utilises an umbilical ‘cross-over’, which allowed both umbilicals to be laid perpendicular to the dominant current direction and clear of any interference risks. An installation methodology was developed to successfully hook up the tether and lay down the umbilicals. Custom components and installation aids were designed for this purpose.