Reducing Fleet Costs in the Central North Sea
Optimising offshore supply operations to cut annual vessel costs and emissions through AI-driven fleet modelling.
Case Study: Overview
PlanSea worked with CNOOC (formerly Nexen) to model and optimise the marine logistics operations supporting four offshore installations in the Central North Sea.
Using its AI-based optimisation and simulation platform, PlanSea identified opportunities to rationalise vessel usage, reduce sailing time, and cut operating costs — without compromising service reliability.
Project Summary
Client:
CNOOC (Nexen)
Sector:
Offshore Marine Logistics
Region:
Central North Sea
Technology:
Plansea Marine Logistics Optimisation
TRL:
8/9 (commercially validated)
The Challenge
The operator maintained a four-vessel supply fleet to service four installations in the Central North Sea.
While effective, the existing routes and schedules did not fully account for overlapping demand or vessel utilisation across installations.
The client sought a data-driven approach to evaluate fleet efficiency and explore optimisation potential.
The Approach
PlanSea used its Marine Logistics Optimisation engine to simulate vessel activity under real-world constraints, including port access, weather, and service schedules.
The system modelled multiple routing scenarios and tested vessel reduction strategies while maintaining full operational coverage.
Through iterative AI-based analysis, the model identified new routing patterns that exploited co-location and reduced redundant voyages.
PlanSea’s optimisation tool gave us clear visibility of vessel utilisation and allowed confident decisions on reducing fleet size.
Client Operations Manager [CNOOC]
The Results
The optimisation identified that the operator’s supply chain could maintain service levels with a two-vessel fleet instead of four, realising immediate cost and emissions benefits.
- Reduction from four to two vessels in the active fleet
- £6 million annual saving in operating cost
- Improved vessel utilisation and scheduling efficiency
- Reduction in CO₂ emissions through decreased sailing hours
The Technology Behind the Results
This project was powered by PlanSea’s AI and Discrete Event Simulation (DES) engine.
The platform accurately recreated offshore supply operations, applied AI-based optimisation to thousands of route combinations, and validated the results against real-world data.
It demonstrated how advanced modelling can deliver tangible cost, time, and emission savings.
- Reduction from four to two vessels in the active fleet
- £6 million annual saving in operating cost
- Improved vessel utilisation and scheduling efficiency
- Reduction in CO₂ emissions through decreased sailing hours
AI Optimisation
Finds the best fleet, route, and schedule combinations.
Simulation Modelling
Tests operational constraints before implementation.
Emission Analytics
Quantifies environmental improvements from optimisation.
Operational & Environmental Benefits
This early demonstration helped establish confidence in PlanSea’s approach and informed subsequent multi-operator and shared-fleet studies across the UK Continental Shelf.
It proved that AI and simulation-based logistics optimisation can deliver measurable impact and align directly with net-zero objectives.
Discover What Plansea Can Deliver
Talk to our team to learn how PlanSea’s optimisation technology can reduce costs and emissions across your offshore operations.
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