Longitude Engineering was contracted by PTTEP to develop the conceptual engineering for a fixed platform decommissioning asset via reverse floatover.
Facts and Figures:
- Can accommodate the removal of 3 types of topsides
- Up to 800 tons topside’s weight
- Potential removal of 90 platforms for PTTEP
- Heave compensated lifting and skidding systems integrated
- 8 points position mooring system
- Accommodation for crew and operation team for 57 POB.
- Designed in line with ABS Class and DNVGL Guidelines for Marine Transportation
Engineering scope:
The scope of engineering services included project management, conceptual naval design, facilities design, removal procedures, material take-off/cost estimation and platform decommissioning procedure.
The naval design analysis included stability and longitudinal strength verifications using GHS software, motion analysis for the different operation stages using MOSES software, mooring analysis, towing analysis and definition of the operational window for decommissioning. In addition, the associated drawings and layouts were produced.
The structural scope included the local verification of the primary steel using Finite Element Analysis software FEMAP, the design of reinforcements and additional steel comprising the lifting frame and topside interface using FE analysis software Staad.Pro and FEMAP.
The mechanical scope included the design of a heave compensated lifting system, a skidding system and the integration of a position mooring system. In addition, the electrical scope covered the load analysis, the power system generation and distribution philosophy and the basic design philosphy of alarms and monitoring systems.
The scope also includes the marine system design, the accommodation layout, deck layouts and various philosophies covering aspects from the Health and Safety to material handling and Flag/Rules/Codes and standards analysis.
Finally, the sets of procedures for transport, load-in via SPMT, topside lifting and overall decommissioning, inclusive of schedule, CAPEX and OPEX costings were produced for the client.
