FEED Design Competition of eight infield pipelines connecting the wellhead platforms and FPSO within Chimsao Field and a gas export pipeline from FPSO to Nam Con Son Trunk-line Tie-in followed by detail design of a 10in 96km gas export pipeline including the associated riser, subsea PLEM and Tie-in Structure.

The infield pipeline diameters were ranging from 4.50in to 10.75in to transport gas, water and crude and the gas export pipeline was a 10in in diameter with a combined length of about 122km in water depths ranging from 95m to 105m.

The Client 

Premier Oil Vietnam Offshore B.V. (POVO).

The Scope 

Design scope include pipelines field layout and routing design, pipeline wall thickness design, on-bottom stability analysis and weight coating requirement, pipelines and risers allowable free span analysis, pipeline cathodic protection and anti-corrosion coating selection, pipeline thermal expansion analysis, pipeline buckling analysis, risers and expansion spools design, riser clamp design, Subsea PLEM and tie-in Structure design, pipeline installation feasibility study, preparation of pipeline specifications, MTO, linepipe and fittings data sheets, Technical Requisition, Vendor Data Review and Technical Bid Evaluation.

The Challenges 

Part way through the detailed design phase, there was a change in the development plan to reduce 2 wellhead platforms to a single well platform. The associated pipeline network had to be adjusted and re-engineered to suit the new development configuration. This was done without impacting the construction and procurement schedules.