Using simulation technology, a Dutch marine contractor has reduced manhour and project costs, while mitigating operational risk
Digital twins are transforming the decision-making and planning processes in the offshore oil and gas, renewable and maritime sectors. As virtual replicas of physical assets, digital twins make it possible to realistically simulate complex offshore installations, train for and anticipate multiple operational scenarios months or weeks in advance and yield significant safety and cost benefits. Using fully connected simulations, operators can even glimpse a few minutes into the future during an actual operation.
Heerema Marine Contractors (HMC) was an early adopter of digital twin technology. The Dutch offshore oil and gas marine contractor owns and operates a fleet of specialised crane and construction vessels and has been using digital twin solutions from Norway’s Kongsberg Digital (KDI) at the Heerema Simulation Centre to support complex heavy-lift projects.
By applying KDI simulators to explore and test challenging and critical installations in the lab before going offshore to start the project, HMC says it can reduce risk and simultaneously improve safety and efficiency, providing its workforce with a clear picture in advance of operations commencing. This had led HMC to label KDI’s digital twins as a ‘force multiplier’ for offshore operations.
“By adopting this methodology, HMC can subject new and innovative concepts to rigorous pre-testing in the virtual realm before committing to the expense and logistical issues involved when turning such concepts into reality,” says HMC simulation and visual design team lead Dave Woessner.
HMC’s Kongsberg Digital simulators use a DNV-GL-certified K-Sim offshore simulator facility with two offshore crane operator domes, winch operation stations and a full mission bridge that has DP simulation capability.
Using the K-Sim Offshore technology as a platform, Kongsberg and HMC developed detailed models of the HMC deep-water construction vessels Sleipnir, Thialf, Balder and Aegir in addition to several support assets and vessels. Used for operator training, the models are constantly being improved and refined with data captured from live operations. The fidelity of the models ensures that HMC can trial any planned operation in its simulators and find out exactly what will happen at sea under various conditions.
Mr Woessner says: “The simulators also enable concepts to be safely developed away from harsh offshore environments, where operations can be seriously compromised by unpredictable weather patterns.”
He adds: “By the same token, the simulators enable comprehensive training programmes to be pursued – a crucial preparatory step when evaluating complicated project plans. KDI’s digital twins also allows HMC to run through failure cases and create mitigating actions, thereby minimising the risk of unexpected issues arising. This in turn improves execution predictability and timing. The logical outcome of these stringent, pre-emptive, simulated scenarios is that operational efficiency becomes increasingly enhanced, leading to substantially reduced overall project costs.”
With high confidence in the accuracy of the results at the simulator centre, HMC optimises complex operations before their ships leave port. They can test different approaches, in different weather and sea states, to ensure they are ready for various conditions on the day.
HMC used the digital twin approach in establishing installation aids, tugger positions and clearance for a flare installation on the Culzean gas field in the North Sea.
“Heerema has been heavily involved in the Culzean gas field project,” says Mr Woessner. “Our client Maersk Oil North Sea UK Limited awarded us the engineering, procurement and construction contracts for the central processing facilities platform, the utility and living quarter platform, the wellhead platform jacket, the wellhead access deck and access ways.”
According to Mr Woessner, while a digital twin of Maersk Highlander jack-up drilling rig helped crews anticipate problems that might arise in the drilling of wells, KDI’s simulators assisted HMC in planning the fabrication, assembly and installation of the grillage and sea fastening for the jackets and piles to allow “every stage of each process to be carried out with pinpoint accuracy.”
KDI’s digital twin technology was also used in the pre-trialling stages of a project intended to demonstrate the effectiveness of HMC’s quad lifting concept. In quad lifting four cranes are deployed in parallel, simultaneously, as a means of enabling topside structures to be built onshore as a complete item during commissioning, saving significant man-hours and reducing project costs.
The KDI simulators in the Heerema Simulation Centre were used initially to assess the feasibility of the quad lifting procedure before being tasked with evaluating its practical worth through subsequent simulation testing. The tests covered various aspects of the projected operation, from rehearsing communication protocols to acknowledging that human intervention could impact upon mission outcomes, and building failure cases into the programme to prepare trainees with as wide a range of scenarios as possible.
Operating in dynamic positioning mode, HMC’s semi-submersible crane vessels Balder and Thialf performed a successful quad lifting trial in the Gulf of Mexico in October 2018.
Plans are now underway for what HMC is calling “the ultimate quad lift,” with a combined lifting capacity of 34,000 tonnes, with the firm’s Sleipnir semi-submersible crane vessel – the largest ever constructed.
“It effectively opens up a whole new array of possibilities from the commissioning and design phases of jackets and topsides onwards, leading to a situation whereby these structures can routinely installed on all types of foundations,” says HMC chief executive Koos-Jan van Brouwershaven.
Other HMC projects where KDI’s digital twin has delivered enhancements include a FEED study for the installation of a 1,000-tonne module on a floating production unit, where concept design of bumpers and guides, verification of complex set-down behaviour and studies of the DP behaviour and settings were all explored. For Statoil’s Peregrino project in the Campos basin offshore Brazil, HMC used the system to test the set-down of several modules, enabling it to define the sequence and test concepts with local conditions, among other factors.
The system is also being used to test applications such as a new back-loading project which had never been carried out before. With no data available from real-life operations, HMC was able to receive accurate verification of all aspects of the job, from concept design of the cones and receptor, and improved workability within the design concept, to weather limitations and alignment of engineers and operators.
“Our in-house Simulation Centre can adapt a variety of 3D models, such as the jackets and topsides for the Culzean gas field project, to our clients’ real component characteristics,” says Mr Wossner. “Three-dimensional drawings are produced by our engineering department and uploaded to the Simulation Centre system, after which offshore crews can perform a dry-run of a given operation, co-operating with the client and our project team.”