JFSE has designed the MultiROV, the first dedicated mass flow excavation package for the deepwater market
With efficiency and cost reduction driving most of the innovation in the industry, multipurpose tools are gaining more traction. In many cases, the ability to take on multiple jobs has also allowed many subsea firms to take on work in sectors other than oil and gas – offshore wind farm development being a particular target in the North Sea. InnovOil has already covered innovations from the likes of Utility ROV Services, and many operators are looking to benefit from the ability to complete multiple aspects of a project using a single vessel.
The latest such equipment comes from James Fisher Subsea Excavation, a unit of marine engineering firm James Fisher and Sons. Formed in 2014 following the combination of KDM Marine and James Fisher’s own mass flow excavation (MFE) business, the company provides a fleet of tools for non-contact subsea excavation. This form of subsea excavation, also including controlled flow excavation (CFE), is preferable around sensitive or complex assets, and allows operations such as pipeline and cable trenching, de-burial, rock dump dispersal and seabed clearance to be undertaken with reduced risk to the asset.
M/CFE spreads are ideal for moving materials such as sand, silt and mud, drill cuttings, clay and rock dump. Its latest innovation, dubbed the MultiROV, is designed to operate a number of different tools during one deployment, increasing the efficiency with which operators can undertake inspection, repair and maintenance (IRM) campaigns.
“The initial design criteria was to develop a system where the proven mass/controlled flow excavation technique could be utilised in the deepwater market,” JFSE technical director Graham explained to InnovOil via email. “We had attempted this a few years ago by hiring an electro-hydraulic power pack and mating our patented excavator to this. Although the concept was solid, we encountered challenges with the design. We decided to design and build our own system, as we were confident there was a market for our expertise in deepwater projects due to enquiries from potential clients.”
Thrust-have Developed in partnership with ROV specialist Aleron Subsea, the MultiROV reduces the services required from a vessel, because it requires no stabilising tuggers or clump weights. Instead, on-board thrusters enable movement and heading control of the tool and allow for the accurate positioning of subsea tools directly over the target area. This means engineers can get to work on undertaking more jobs, with less time waiting around.
Weighing 2.5 tonnes and needing a volume of just over 2 cubic metres, it is deployed via 20 tonne SWL lift frame with hydraulic locking ram. Four 380-mm hydraulic thrusters provide up to 300 HP of excavation power, with a maximum flow of 600 litres per minute, and maximum pressure of 300 bar. In low light conditions, 4 LED lights provide illumination.
“Any vessel with a crane or A-frame would be suitable for deploying the seven tonne MultiROV. One of the main benefits of utilising this system is it reduces the demand on the vessel,” Murdoch added. Versatility is also important. Because it does not require stabilising infrastructure, it can be used at any depth over 4 metres, down to 3,000m and below. In that regard, the company says, it the first fully dedicated M/CFE tool for the deepwater market.
The MultiROV then provides a platform to operate additional subsea tooling, such as grabs, shears and suction dredgers, again without the need for separate tool deployment.
Autoheading and depth feedback come as standard, meaning the system will maintain its own position, but the system boasts additional data-hosting capabilities, allowing it to run a multitude of useful subsea survey sensors, including cameras and multi-beam sonars. This enables added flexibility in terms of real-time data capturing during operations, and helps operators better assess the condition and layout of their assets and the seabed.
In a separate statement, Murdoch commented: “This is an exciting advancement in excavation technology. The MultiROV will bring real benefits to our clients with a range of challenging requirements. Automated heading and positioning controls greatly increase both productivity and the operational working limits.”
In total, JFSE offers a range of 30 equipment spreads, all of which are capable of real-time sonar imaging. This enables precision excavation in confined areas, as well as for all cable or pipeline trenching works with diameters from 1” to more than 60” scopes (25-1,524mm). As well as deepwater operations, JFSE believes the system will offer major benefits to its work in the decommissioning and offshore wind farm markets.
JFSE works from a number of hubs in the UK, UAE, Singapore, Venezuela, USA, Brazil, China and Mexico. As such, it believes it is the only M/CFE contractor capable of working on multiple projects simultaneously. The MultiROV will no doubt play a central role in enabling this further.