Key Takeaways:
- Controlled Mass Flow Excavation (CMFE) enables safe, non-contact removal of seabed sediment, ideal for pipeline de-burial, seabed levelling, and decommissioning.
- Uni-FlowX delivers high-precision, low-impact excavation with sonar imaging, modular frames, and variable power settings.
- The system reduces environmental risk, supports rapid mobilisation, and performs in high-current, low-visibility zones.
- Real-world deployments, like in Bangladesh, demonstrate Uni-FlowX’s ability to handle complex seafloor intervention with minimal disruption.
- Unique Group’s in-house R&D and global engineering support ensure complete lifecycle project execution—from equipment to offshore support.
The offshore and subsea engineering industries are undergoing a pivotal transformation. As global energy systems diversify and critical infrastructure expands beneath the ocean surface, the requirements for seafloor intervention have become increasingly complex. From oil and gas to offshore wind and undersea cable routing, today’s projects demand a new level of precision, environmental sensitivity, and control.
Traditional excavation methods—mechanical digging and heavy dredging—were once the norm. But as operations move into more dynamic and ecologically sensitive zones, these approaches are no longer sufficient. Stronger currents, tighter environmental regulations, and fragile infrastructure require next-generation excavation systems designed for accuracy and minimal disruption.
Modern seafloor engineering has evolved beyond physical excavation alone. The focus now is on smart systems that combine data, adaptive design, and automation. Removing sediment effectively is just the beginning—today’s tools must also safeguard assets, reduce environmental impact, and deliver consistent results in unpredictable underwater conditions.
Operators increasingly need tools that are rapidly deployable, precisely controllable, and capable of operating safely in challenging environments. This has accelerated the shift toward excavation solutions that blend mechanical reliability with real-time monitoring and modular design.
Among the most transformative of these advancements is Controlled Mass Flow Excavation (CMFE). Unlike traditional dredging, CMFE uses high-volume, low-pressure water flow to suspend and relocate sediment without direct contact with the seabed. This method dramatically reduces the risk of damaging pipelines or cables and eliminates the need for spoil removal, enhancing efficiency and environmental compliance.
CMFE is highly effective across varied seabed types—from soft sand to compact clay and rock dump—and is ideal for tasks such as pipeline & subsea structure de-burial, cable route preparation, seabed levelling, decommissioning offshore structures and debris clearance. It is especially valuable in shallow, high-risk areas where conventional methods pose safety and environmental challenges.
Decommissioning offshore structures often includes the removal of submerged components such as pipelines, mattresses, and jackets. These operations require a precise and minimally invasive approach. Unique Group’s engineering solutions like Uni-FlowX— a non-contact excavation system equipped with a subsea digger—improve seabed access while minimising ecological disruption. When paired with pipeline and umbilical recovery systems, it simplifies one of the most technically demanding phases of a decommissioning project.
Today’s CMFE systems incorporate sonar imaging for real-time monitoring, variable power settings, and compact frames for easy deployment from smaller vessels. These features enable precision excavation in complex settings while reducing operational downtime and risks.
Engineering Capability at Scale: Unique Group and Uni-FlowX
Unique Group, a global leader in offshore and subsea solutions, has extensive engineering capabilities that span the full lifecycle of subsea infrastructure—from planning, design, and installation to inspection, maintenance, and decommissioning. With 20+ operational hubs worldwide and over three decades of experience, the company delivers full lifecycle support for subsea infrastructure—from planning and installation to maintenance and decommissioning. In addition to engineering and equipment supply, Unique Group also provides trained field service technicians to support offshore projects on-site.
Its in-house Engineering and R&D division is central to its value proposition, driving the development of bespoke technologies tailored for offshore environments. Recent solutions include diver decompression chambers with integrated monitoring, compact launch systems for rough seas, and buoy platforms equipped with environmental sensors.
A major milestone from this team is the Uni-FlowX Controlled Mass Flow Excavation System. This solution is the result of over a decade of R&D, field testing, and client collaboration. Uni-FlowX delivers a high-performance, contactless excavation method designed for safety, accuracy, and environmental stewardship. Using high-volume, low-pressure water jets, Uni-FlowX fluidises and displaces sediment without impacting subsea structures. Its contactless operation reduces risk and simplifies logistics, especially for projects involving buried assets in environmentally sensitive areas.
To ensure precision, Uni-FlowX features real-time sonar imaging for visual tracking—even in poor visibility—and modular construction for easy mobilisation. The complete system includes a Launch and Recovery System powered by a 37 kW Hydraulic Unit, main and clump weight winches, and a data umbilical reel. Integrated variable power control allows operators to tailor excavation force to seabed conditions—supporting accurate, efficient sediment removal.
Real-World Impact: Excavating a Buried PLEM in Bangladesh
Uni-FlowX has been deployed successfully across applications such as pipeline de-burial, and seabed levelling. One standout case involved a buried Pipeline End Manifold (PLEM) in the estuarine waters of Bangladesh — a high-risk, low-visibility environment with powerful tidal currents.
The PLEM was buried under dense silt and sand. With limited diver access and short operational windows, traditional excavation posed too many risks. Unique Group mobilised Uni-FlowX alongside a custom-designed Launch and Recovery System for fast deployment. The system’s contactless excavation allowed large sediment volumes to be removed without damaging the buried infrastructure. Sonar imaging provided real-time feedback throughout the process, and the compact system ensured efficient mobilisation within tight tidal schedules.
This successful operation demonstrated Uni-FlowX’s core strengths: high-precision excavation, reduced environmental impact, and operational flexibility in complex conditions. It also highlighted the value of a responsive, technically capable engineering partner.
As marine infrastructure continues to grow and reach more challenging environments, the demand for safe, intelligent, and low-impact tools will rise. Systems like Uni-FlowX embody the future of subsea excavation—balancing performance, environmental care, and control.
Unique Group’s comprehensive engineering capability—from equipment innovation to full-service project delivery—ensures that even the most complex challenges in offshore energy and infrastructure can be met with confidence. With end-to-end services from customisation to post-operation analysis, the company delivers complete engineering solutions. Its combination of advanced technology and deep operational experience helps clients execute complex projects with confidence.
Seafloor intervention is now a multidisciplinary challenge, blending environmental science, engineering, and logistics. Through ongoing R&D and a practical, field-focused mindset, Unique Group is helping shape a smarter, more sustainable future for the subsea industry.
Read more to see how Uni-FlowX supported projects across South East Asia, Malaysia, and Bangladesh—demonstrating its impact in real-world decommissioning and seabed intervention scenarios.
This article was also featured in Sea Technology Magazine
