OGGS RPA platform left during the dewatering of the Bonga Export Gas pipeline and right picture showing the BONGA FPSO with the vertical flow lines and water injection lines and the Polaris on the right.
In 2004 Stolt Offshore were commissioned by Shell Nigeria to install and pre-commission the pipelines for the new FPSO (Floating Production Storage and Offloading system) vessel which at that stage was the largest FPSO in the world which is situated on the Bonga field about 100 km off the Niger Delta in 1000 metres water depth.
The pipelines included a 16 inch export gas line to take the gas to the RPA OGGS (Offshore Gas Gathering System) Platform situated just off the delta in 20 metres water depth as well as a series of flexible flow lines and water injection lines on the Bonga Field. These pipelines were laid by the Polaris Derrick Lay-barge using a J lay on the flexible lines and an S lay on the gas pipeline. At 1000 metres water depth this was the deepest S lay that had been undertaken.
Wale Marine were initially commissioned by Stolt to perform the pre-commissioning of the gas pipeline as resident manager on the receiving RPA platform. This work included the pig cleaning of the line followed by the drying of the line which was performed by pumping a series of foam pigs to accelerate the drying given that the temperature in the deep water was 4 degrees. After the drying of the line we needed to install the emergency shut down valve.
After the completion of the Gas pipeline pre-commissioning Wale Marine were commissioned by Stolt to act as the resident project manager to supervise the pre-commissioning of the flow lines and water injection lines on the FPSO.

