Poseidonoffshoreenergy

MaMPU FPSO – Crude Stabilisation Unit (CSU) Detailed Design & Installation Engineering

The MaMPU FPSO operates offshore Malaysia as part of Petronas’ upstream production network.

The Crude Stabilisation Unit (CSU) was designed as a modular topside process unit to improve the separation and treatment of produced fluids prior to export. The CSU module required detailed structural design and installation engineering to ensure safe integration with the FPSO deck structure and compliance with offshore design standards.

Task

The engineering scope covered the complete detailed design and installation engineering of the CSU module, including:

Structural analysis and design using SACS and ANSYS.
Transportation and loadout analysis of the CSU module.
Rigging and lifting design, including sling and shackle configuration and crane capacity checks.
Ballasting and stability analysis for the barge during loadout and lifting operations.
Preparation of design reports, method statements, and barge ballasting plans.

Challenges

Accuracy required during design and construction to ensure proper integration of the CSU module with the FPSO deck.
Ensuring safe lifting arrangement design considering crane limitations and offshore environmental conditions
Managing loadout and the transportation of the CSU module.
Ensuring accurate positioning and alignment of the SGS during installation.

The Solution

The primary and secondary framing system of the CSU was modelled in SACS to assess global and local strength under all critical phases including construction, transportation, and offshore lifting. The analysis verified member stresses, joint efficiencies, and deck interface connections against API-RP2A and AISC design codes. Localized FE checks were performed in ANSYS to confirm stress concentrations at lifting padeyes and support nodes, ensuring a robust and fabrication-ready design.

The lifting and rigging arrangement was engineered to achieve optimal load distribution and minimize sling angles. Spreader beams, slings, and shackles were sized and verified using combined static and dynamic load cases. Crane radius and capacity checks confirmed safe lifting margins under design sea states and heel conditions.

An integrated barge-cargo model was developed to simulate the transportation phase, capturing barge deflection, grillage interaction, and hull girder strength. The barge scantlings were checked for buckling, yielding, and crippling using classification society criteria, while longitudinal and transverse bending moments were validated against allowable limits.

Ballasting and stability simulations were conducted using Maxsurf and Hydromax to predict barge trim, heel, and draft during each operation — loadout, float-off, and lifting. Equilibrium analyses determined ballast water sequencing to maintain stability within intact and damaged criteria. A bollard pull analysis established the minimum tug capacity required for safe towing during transportation.

Figure 2 – CSU Loadout
Figure 3 – CSU Skidding

All engineering outputs — including method statements, ballast plans, rigging design sheets, and analysis reports — were consolidated into a comprehensive Installation Engineering Dossier, ensuring full traceability, constructability, and compliance with offshore installation standards.

An integrated barge-cargo model was developed to simulate the transportation phase, capturing barge deflection, grillage interaction, and hull girder strength. The barge scantlings were checked for buckling, yielding, and crippling using classification society criteria, while longitudinal and transverse bending moments were validated against allowable limits.

Ballasting and stability simulations were conducted using Maxsurf and Hydromax to predict barge trim, heel, and draft during each operation — loadout, float-off, and lifting. Equilibrium analyses determined ballast water sequencing to maintain stability within intact and damaged criteria. A bollard pull analysis established the minimum tug capacity required for safe towing during transportation.

Summary

The CSU project demonstrates Poseidon Offshore Energy’s capability to execute detailed structural design and installation engineering for complex offshore topside modules. The team successfully applied advanced analytical techniques and integrated modelling to ensure safe loadout, transportation, and lifting of the CSU module on the MaMPU FPSO.

Engineering Tools:

ANSYS, SACS, MathCAD, AutoCAD, Maxsurf and Hydromax

Key Deliverables:

Key Deliverables: Detailed Design Reports, Structural Analysis Package, Lifting & Rigging Design, Ballasting Analysis Report, Stability Assessment, Method Statements

Project Information

Completely synergize resource taxing relationships via premier.

Client Name

Petronas Malaysia

Category

Showcase