The Subsea Power Hub, developed by Aberdeen-based EC-OG, is a seafloor turbine which the company hopes could change the economics of powering subsea equipment
Powering oilfield equipment is difficult; powering it on the seafloor several kilometres from the surface is even more so.
Typically, that can be done from the surface via long tiebacks. Indeed, for multiphase pumps, compressors and other turbo-machinery, which can require megawatts of electricity, surface power is likely to be the only economic solution. But with failure of these umbilicals being one of the most common reasons for downtime and lost production, siting power generation infrastructure at the equipment itself could help increase safety and improve margins.
Recognising the need for more sustainable, reliable subsea power, East Coast Oil & Gas (EG-OG) was set up to support the development of its renewable innovation – the Subsea Power Hub (SPH). Founded in 2013 by managing director Richard Knox and engineering director Rob Cowman, EC-OG has established a sound reputation in engineering services covering wellheads, Xmas trees and intervention systems, while the SPH has continued to pique industry interest.
Based on a familiar subsea template, the SPH supplies electric power from up to three turbines mounted in the centre of the frame.
Typical seafloor current strength is around 0.4 m/s, meaning each turbine will deliver an average base-case output of 300 kW per annum, and the largest models will produce around 150kWh per year. Hubs can also be clustered and configured by a distribution network for larger project footprints.
An intelligent energy management system (IEMS) optimises battery life by considering the energy available in ocean currents and the repeat performance of the unit in powering battery system, helping to increase design life far beyond battery-only systems.
While typical battery systems may last around a year alone, the SPH can extend this indefinitely, at full capacity over the intervention period.
This also allows the SPH to power continuous monitoring, control and communications systems, as well as intermittent high-power tasks, such as high bandwidth communications.
The lightweight frame and overtrawlable structure allow the SPH to be fairly transportable, and to be deployed from a standard construction support vessel (CSV). This also permits it to be re-deployed and re-used. EC-OG also plans for a flexible business model which would include SPH as a rental system, offering producers power supply with no CAPEX required.
Since 2013, EC-OG has garnered significant investment and support for the project such as several large grants from the Scottish government and Scottish Enterprise as part of the latter’s High Growth Ventures Unit. More recently, it secured a further GBP1 million (US$1.3 million) in external investment from Castle View Ventures and the Scottish Investment Bank, which will take the SPH through to the in-house prototyping phase.
According to EC-OG, a single-turbine prototype should be complete by the end of November. A full, three-turbine prototype is expected to follow in 2017.
“It’s a very exciting time here at EC-OG,” Knox told InnovOil. “Over the next year, the team will be working hard to push forward with the commercialisation of the Subsea Power Hub. We are fortunate to be in a position where we have had concrete votes of confidence in the strategy of the company. It’s great to see that people are reacting positively to our innovative idea.”