Projects

Accelerated corrosion technology trial optimises steel removal post-decommissioning

3-SCI Ltd conducted a 'TELOS' (Technical, Economic, Legal, Operational and Scheduling) feasibility study.

Completed over a 14-week period, it explored a new method of removing subsea metallic structures via an accelerated corrosion technique, which can cut or fully dissolve steel. This would have both cost and environmental benefits compared to traditional methods, where steel is either left subsea or returned to shore.

This technology has the potential to increase the rate at which steel is currently eliminated, enabling a reduction in time and cost efficiency.

Industry Value

The removal, long-term surveillance and potential intervention associated with steel structures remaining subsea post-decommissioning is a significant cost to industry.

Workshop data suggest that C-Beaver tools could dissolve steel at the rate of ~100 Kg per MW-hr (approximately 10 watts eliminating 1 gram of steel per hour).

For example:
Applying 10 kwatt to 100 feet of 38lb/foot steel tubular using the C-Beaver method could reduce it to its corrosion product within two months.

A 6 MWatt capacity offshore wind turbine (assumed creating average power at approximately 25% of capacity, could help eliminate steel at the rate of approximately 1000 tons per year.

Technology Organisation

3-SCI Ltd

3-Sci Ltd is run by a team of technical specialists who have experienced in research, product and business development in the engineering, physical and materials sciences. They offer various products in the industrial asset monitoring sector, including our Wi-Corr, wireless remote corrosion monitoring system.

http://www.3-sci.com

Project3-SCI Ltd - C-Beaver Phase 1- Technical, Economic, Legal, Operational and Scheduling ('TELOS') study

Challenge

Decommissioning

Vision

Transform Tomorrow

Entry TRL

4

Field Trial

No

Technology

Electrical tool to disolve steel by accelerated corrosion & cuts through small lengths of subsea pipeline study

Type

Adapt

Achieved TRL

4

Technology Organisation

3-SCI Ltd

3-Sci Ltd is run by a team of technical specialists who have experienced in research, product and business development in the engineering, physical and materials sciences. They offer various products in the industrial asset monitoring sector, including our Wi-Corr, wireless remote corrosion monitoring system.

http://www.3-sci.com

Key Results

Phase 1 was completed in 2018, which consisted of a feasibility study and labratory trials to prove the technology.

Phase 2 was recently approved and, through field trials, will demonstrate that accerelated corrosion can eliminate, cut or drastically reduce the mass of subsea structures. 

Lessons Learned

1. Validation of the accelerated corrosion technique on a larger scales (e.g. using large water tanks) is required.

2. Additional studies are required to confirm the precise approaches for provision of power.

3. The approaches to effectively eliminate the various coatings and electrically-isolating barriers on steels needs to be defined.

4. Design and early prototyping work should commence for the production of a large scale accelerated corrosion tool prototype for sea trials.

5. Assuming a positive outcome of recommendation 1, and no early 'blockers' being identified through recommendations 2 and 3, an Environmental Impact Assessment (EIA) should be conducted. This should focus on the possibility of discharging the accelerated corrosion products directly into sea. The outcome of this EIA may influence the nature of prototyping work and the scope of application of accelerated corrosion.

Next Steps

Transition to phase 2, which inlcude field trials and validation of the technology.