Moderated by: Bente Festøy, Equinor ASA and Rune Vesterkjær, Aker Solutions

15:10 - 15:30 

Zero Emission Underwater power Station – ZEUS
Kjartan Pedersen - Aker Solutions AS 

ZEUS produces electrical power by burning natural gas with pure oxygen. The combustion is done at 80 bar by utilizing the well pressure. The high pressure ensures that when cooled, the exhaust is liquefied directly into water and CO2. The CO2 (and water if one so chooses) can then be re-injected directly into the same reservoir or a nearby aquifer, using a pump and not a compressor. The injected CO2 can prolong production of existing fields, and is permanently stored when the field is shut down, never leaving the seabed. The only thing leaving the seabed is a power cable. 

By requiring only a cable to shore, ZEUS is not only an environmental sustainable solution, but an economical attractive solution as well.

In addition pressurized oxy-fuel combustion eliminates costly pre-processing of the feed gas and costly post-processing of the flue gas. And finally, the short distances from production and injection wells to ZEUS save much on costly piping infrastructure.

ZEUS can produce emission free power from any gas including associated gas, CO2 rich gas, stranded gas, and methane hydrates. The power can then be used for offshore installations and/or be sold to any suitable onshore grid.

The liquid CO2 and water can be injected for permanent storage or utilized for EGR or EOR before being permanently stored. 

Finally, prolonging life of a field delays any costly P&A measures including opening up for commercial CO2 storage after production has stopped and/or trading in green certificates, creating new revenue streams.

15:30 - 15:50

Repurposing subsea technology for decarbonization and new-energy solutions
John Olav Fløisand - OneSubsea 

The energy landscape has always been dynamic, however, the ever-growing need for emission action has increased significantly over the past few years, accelerating the push for renewable sources to become the dominant share of the energy mix. Major oil and gas corporations are transitioning into energy companies, while suppliers are shifting gear to reflect these evolving perspectives. At the same time, the availability of energy is becoming less predictable, and gas and electricity prices are more volatile.

The energy transition outlook shows that hydrocarbons will remain a major source of energy for decades to come. However, a decarbonization pathway for the entire hydrocarbon value chain will be required to meet our sustainability commitments. With more than 70% of the planet covered by water, offshore and subsea technologies can be repurposed, offering great opportunities to generate new energy and low-carbon solutions. These opportunities include, among others, sustainable energy production and storage, carbon disposal, and zero-emission shipping.

For more than half a century, the subsea industry has developed an outstanding array of technology and competence. We believe that these will not become obsolete during the energy transition. Instead, they will be instrumental building blocks to realize new prospects and be part of the low-carbon energy market.

This presentation will provide some insights into how some of the conventional subsea technologies can contribute to decarbonization, and how our existing experience and know-how will be relevant in future offshore energy solutions, both in the short and long term.

15:50 - 16:10

Quantifying greenhouse gas emissions from decommissioned oil and gas steel structures: Can current policy meet Net Zero goals?
Abigail Davies - University of Aberdeen, National Decommissioning Centre

To help achieve global aims to reach Net Zero greenhouse gas (GHG) emissions, a clearly structured method for calculating emissions from decommissioning oil and gas structures is required. In order to understand the GHG consequences of recycling secondary steel from decommissioned structures, this paper presents a new methodology in decommissioning, based on the UN’s International Resource Panel (IRP)’s Value Retention method that combines life cycle assessment principles, the waste hierarchy and the circular economy to holistically calculate GHG emissions produced as a consequence of manufacturing primary and secondary steel, manufacturing a product from this steel and the associated transport emissions. The Value Retention Model presented here combines the concept of material value and product value to obtain realistic GHG emission calculations based on end-of-use and end-of-life scenarios, including recycling and reuse options. The results show that reusing a steel jacket structure in situ will retain 55,040 tCO₂(eq) in GHG emissions, not including removal operations or transport emissions. New regulation is urgently required to update the current outdated emissions calculation guidelines, enable the provision of both realistic baseline emissions figures and to provide a mechanism for reporting ‘after operations’ figures. 

16:10 - 16:30

Supercharger and sHPU – 2021 Fjordtest
Johannes Fjelland Moi - Innova AS 

Teledyne Energy Systems (Teledyne) and Innova are performing a demonstration of a fuel cell-powered subsea hydraulic power unit (sHPU). The fuel cell being Teledyne’s Subsea Supercharger, a power source which can deliver multiple megawatt hours of energy to subsea devices. The Subsea Supercharger is comprised of a fuel cell module, switch gear/ power conditioning module, and a hydrogen and oxygen reactant storage system. The sHPU has been developed by Innova and is geared to supporting untethered well interventions.

The demonstration has great relevance for the subsea industry as directly addresses a pathway to provide services without a dependency on a subsea power grid. The project merges the capacity of Teledyne’s Subsea Supercharger and Innova’s electrohydraulic pump for low viscosity fluids (sHPU). The demonstration project allows technology gaps to be closed by integrating advanced technology in realistic applications and under actual operating conditions. In the fjord test, conducted at the Tau Autonomy Center outside Stavanger, energy in the form of pure hydrogen and oxygen is converted into hydraulic pressure of subsea control fluid at 235 meter water depth. A world first, this demonstrates how hydrogen can be used for local power of subsea control systems.

This presentation will review lessons learned from operating the Subsea Supercharger during the well intervention simulations at Tau. It will explain the novel system features of the Subsea Supercharger integrated with the sHPU. Lastly, the presentation will status the deep-water ocean and gas community of the Subsea Supercharger’s availability for addressing their future power needs.