The challenges for this project were the water depth at the site, the metocean environment and the geotechnical conditions.

The topsides for this application were minimal – essentially comprising large bore piping runs and valving for import and export risers, cooling water caissons and trees.  The topsides also must accommodate the required well workover equipment.   The platform was designed to accommodate two wells, three risers and one J-tube.

A variety of alternative structural geometric configurations were evaluated.  These alternatives were deviations from a conventional slimline jacket due to the loads imposed by the design storm cases in this relatively deep-water application.

Foundation System Alternatives

In addition, alternative foundation systems were studied including several conventional pile configurations as well as suction cans.  A four-piled configuration was the optimal solution considering the total installed cost and technical risk.

Field Development Optimisation

The field development plan was developed which included a MOPU and a bridge linked Conductor Support Frame (CSF). The inclusion of the CSF allows for an early hook-up and commissioning of the subsea facilities to the CSF, accelerated drilling and completion of the wells throughout the field and rapid hook-up of the MOPU.

The selected platform configuration, as shown in the attached figure, met all the required criteria including pile loadings, topsides lateral displacement, ability to install with the jack-up rig, and overall cost.