Significant project schedule- and cost-related risks in FPSO life extensions and re-deployments are widely recognised. Deltamarin offers advanced design methods and tools to reduce these risks considerably at the design phase.
Challenges in hull design
Typically, existing crude oil carriers are highly optimised to comply with class rule requirements for tanker service. When such a vessel is converted into an FPSO, offshore production unit rules are applied allowing the use of direct analysis tools.
It is quite common that design analyses applied to classification show little if any margin for life-extension or, for example, topside module load increases. Re-deployment projects need to solve the resulting capacity issues with often costly and extensive hull modifications.
Tight scheduling and available resources usually dictate the selection of analysis tools applied during the FPSO conversion design stage. After all, the target has been to achieve classification approval and not documentation of the true structural capacity. Intelligent use of advanced, fit-for-purpose analysis tools may result in a significant difference in hull modification extent and costs.
Benefiting from sophisticated analysis
“The level of the analysis sophistication has sometimes made a significant difference in real FPSO projects. To give some examples, combining time domain- and spectral-based analyses was necessary to develop more realistic design load cases for the bow-turret connection in a recent conversion project. Spectral-based analysis increased the calculated fatigue life considerably compared to simplified fatigue analysis; factors greater than 100 were even achieved. A non-linear analysis was applied to the calculation of buckling capacity, way above that of simple rule formulae. Time domain approaches were required for mooring components to exclude numerical fatigue failures calculated by other approaches,” says Timo Mikkola, Chief Structural Analysis Engineer at Deltamarin.
The Deltamarin hydrodynamic load and structural analysis toolbox is a result of continuous development where experience gained from FPSO conversion, life-extension and re-deployment projects is utilised. At present our in-house analysis capabilities and resources complemented by our large network cover a full range of hydrostatic, hydrodynamic and structural analysis tools with a wide range of result analysis tools for strength, buckling, fatigue and other specialised purposes. The level of analysis ranges from simplified rule-based formulae to frequency and time domain approaches.
The key is to select tools with the level of sophistication needed to make the right decision on the required design strengthening and structural modifications.
Deltamarin supports you in reducing project CAPEX
“Design and engineering costs typically represent only a minor share of the total CAPEX in an FPSO project. Nevertheless, decisions made at the design phase always have a significant influence on yard construction costs. With accurate design analysis, the maximum capacity of the existing hull can be well utilised. Hence, major savings in materials and labour can be achieved as steel renewal and additional strengthening are minimised,” says Jaakko Lappi, Sales Manager at Deltamarin.
Deltamarin specialises in designing safe and reliable floating production units even for the harshest environments. As a one-stop design and engineering partner, Deltamarin offers expertise for your demanding new building, conversion, re-deployment and life extension projects in:
- GAP analysis and feasibility
- Hull strength and fatigue
- Motions and stability
- Turret, mooring and riser load analysis
- Machinery and power demand
- Marine system and utilities
- Electrical, Instrumentation and Control
- Lifesaving systems & HSE
- Interface management
- Class approval
Deltamarin has several solid references in supporting FPSO owners, shipyards and oil companies globally.
We welcome you to contact us for further discussion with our world-class engineering team. Let us know how we can support you.
For more information please contact
Tel. +358 2 4336 344
Mobile +358 40 834 8112