Marine Geotechnics
Before installing an offshore platform, a port terminal, a pipeline or a wind farm at sea, you need to know the soil beneath the seabed. Marine geotechnics investigates that subsurface with our own means, in sheltered waters, open sea, rivers, tailings dams and lakes, providing the data that guarantees the technical feasibility and safety of the project.
What we deliver
Seven lines of investigation carried out from floating means, from conventional drilling to continuous piezocone testing.
- Rotary drilling
- Mixed drilling
- SPT and SPTT percussion drilling
- Shelby and Denison sampling
- CPTu / CPT piezocone
- Vane test
- Vibracore sampling
How we do it
The investigation combines rotary, mixed and percussion drilling (SPT and SPTT) carried out from floating means, with Shelby and Denison sampling for laboratory strength and consolidation testing. The CPTu (CPT piezocone) is pushed continuously into the seabed soil, or from an already-drilled borehole, measuring in real time the tip resistance, sleeve friction and pore pressure, with no need for physical sampling. The vane test complements the characterization of soft clays, directly measuring undrained shear strength. Vibracore sampling is used mainly in shallow investigations, such as submarine cable routes. The campaign covers everything from sheltered waters and rivers to open sea, tailings dams and lakes, including port terminal expansion and dredging projects.
Our own means
GEOSEA operates its own self-elevating barge, GEOSEA III, alongside platforms, a drilling bell and drill ships, covering everything from sheltered waters and rivers to open sea, tailings dams and lakes — including port terminal expansion and dredging projects.
- Floating barge
- Platforms
- Drilling bell
- Drill ships
Reference depths and capacities
Reference figures from our offshore campaigns, according to foundation type and project scope.
- Investigation depth for fixed foundations (monopile/jacket)
- 50-70 m
- Typical investigation depth for submarine cable routes
- up to 5 m
- Combined water + borehole depth capacity (reference systems)
- up to 3,500 m
Technical standards
Marine geotechnical investigation follows international standards specific to offshore foundations, guiding everything from campaign planning to result interpretation.
| Item | Valor |
|---|---|
| Petroleum and natural gas industries — Specific requirements for offshore structures — Part 8: Marine soil investigations | ISO 19901-8:2023 |
| Offshore soil mechanics and geotechnical engineering | DNV-RP-C212 |
Honest limitations
We publish where the method reaches its limits — mastering a technique also means knowing where it stops.
- Marine geotechnical investigation is typically the most expensive stage of an offshore project, representing a significant at-risk investment before the final decision.
- It is predominantly intrusive: it requires heavy mobilization and depends on favorable weather windows.
- The scope of the campaign depends directly on the chosen foundation type and the variability of the seabed in the region.
Need to investigate the subsurface of your marine project?
Talk to our team and get a proposal tailored to your offshore project.
Contact us