Insights
Expanding the working limits of geotechnical projects
You can’t change the weather, but thoughtful design and selective automation can make it matter less – starting campaigns faster, running them longer and resuming sooner.
Geotechnical survey campaigns are measured in hours of workable sea state. Extending those hours depends less on appeasing Poseidon and more on design. Here, Jack Berryman, co-founder of marine geotechnical drilling specialist MintMech, looks at how thoughtful design and selective use of automation are making geotech surveys shorter and more productive.
No matter how salty they are, no engineer can control the weather. What they can influence is how long it takes to start work, how long work continues before bad weather arrives and how quickly it restarts afterwards.
Mobilisation is a case in point. Time spent on deck is costly, so every hour saved is worth having. Equipment designed to be fitter-friendly, with access, interlocks and clean service runs in mind, can be assembled more quickly and with fewer errors.
We use a tiered design process. Primary deliverables are the big structural members, such as the main framework, lifting points and the drill mechanism itself. Secondary deliverables cover access and fittings: ladders, walkways, handrails, pipe brackets and other components that make the system workable offshore. Tertiary deliverables include the finer details, such as sensor mounts, interlocked gates and tidy routing of hoses and cables.
By treating each tier as part of the design rather than as improvised additions, the kit arrives on the dock ready for rapid mobilisation. A full factory acceptance test and quality pack shorten mobilisation further, and when an auditor or client inspector asks to see the safety file, everything can be handed over without delays or awkward questions.
Once at sea, flexibility helps maximise working time. For example, switching between seabed drilling and cone penetration testing (CPT) often requires time in port. But a palletised system, where modules can be swapped on deck, avoids that costly detour. We aren’t the first to do this, but building such flexibility into the design from the start makes it more reliable and easier to operate.
The point of deployment can also affect working limits. Deploying from an A-frame on the stern might be relatively simple, but it amplifies vessel response to heave compared to midships, near the vessel’s roll centre. Designing a deck spread that lets you use the moonpool could provide hours of extra drilling time per day compared to having to wait for good stern deployment and recovery conditions.
Opportunities for automation
Full autonomy for geotechnical drilling rigs is still a way off, but many opportunities for automation exist. Systems like automated pipe handlers and iron roughnecks reduce the need for manual intervention in areas of high motion. Crews can keep working closer to the weather limit without taking additional risks, and core recovery rises accordingly.
Automation can also help manage another challenge to the industry: the limited supply of experienced marine geotechnical drillers. Offshore geotechnical drilling lacks the structured training routes that support oil and gas and, as older hands retire, embodied knowledge is lost.
Well-designed equipment helps close this skills gap by shouldering more responsibility. Robust systems that are intuitive to use place less reliance on existing expertise and more on engineering repeatability.
No amount of clever design will alter the fundamental constraints imposed by metocean conditions. Waves still dictate when drilling must stop. But attention to mobilisation, in-field flexibility, deployment solutions and targeted automation ensures campaigns can start faster, run longer and resume more quickly once sea state settles.
The result is more metres of core per charter day, and steadier progress towards the offshore infrastructure the energy transition depends on – without the sacrifices to Poseidon.