North Sea reservoir confirmed suitable for CO2 storage

A Danish North Sea reservoir and infrastructure have been determined suitable for geological CO2 storage, as part of the Project Greensand with Wintershall Dea, Ineos, and Maersk Drilling as its members.

Danish drilling contractor Maersk Drilling joined the CO2 storage project in June 2020. The drilling contractor expects that its offshore rigs will be used to repurpose the existing oil and gas wells for CO2 injection.

The consortium is working to mature one of the most progressed carbon capture and storage projects inside Danish jurisdiction and targets the development of CO2 storage capacity offshore Denmark based on reusing discontinued offshore oil and gas fields for permanent CO2 storage.

In an update on Wednesday, Maersk said that the mission to store CO2 beneath the Danish North Sea has cleared the first major hurdle after the intended subsea reservoir in the North Sea was confirmed feasible for CO2 injection by independent certification body DNV GL to the endorsement of Danish authorities.

With this certification of feasibility to DNV GL’s Carbon Capture and Storage certification regime and the international standard, Project Greensand has successfully completed the first phase of validation of the project aiming to develop the capacity to deliver a significant part of Denmark’s CO2 reduction target by reusing discontinued offshore oil fields.

The certification of feasibility issued by DNV GL concerns the Nini West reservoir in the North Sea operated by Ineos Oil & Gas Denmark which is leading the Project Greensand consortium.

According to Maersk, DNV GL confirmed that the Nini West field is conceptually suitable for injecting 0.45 million tonnes CO2 per year per well for a 10-year period and that the subsea reservoir can safely contain the CO2 in compressed form.

Further, the Geological Survey of Denmark and Greenland (GEUS) acts as a research partner to the project and is in the process of performing laboratory experiments of core material from the actual Nini West reservoir.

Project Greensand targets having the first well ready for injection from the Nini platform in 2025. Longer-term, the ambition is to develop the capacity to store approximately 3.5 million tonnes CO2 per year before 2030.

Like the majority of carbon capture and storage projects currently being developed within Europe, the establishment of a funding model is required to mature Project Greensand to a state where CO2 injection can begin.

Maersk Drilling explained that it expects that Project Greensand will provide important learnings about how offshore drilling rigs and capabilities can be used to repurpose existing oil wells for CO2 injection and handle well modifications during the injection period.

”As a trusted voice to the industry, DNV GL is pleased to participate in a project with an important objective to significantly reduce the CO2 footprint by issuing this industry certification following our CCS certification scheme”, says Mick Cramer Jakobsen, Director Capital Projects, DNV GL.

Marika Reis, Head of Innovation, Maersk Drilling, said: “We’re thrilled to get this independent certification that Nini West is suitable for injection and long-term safe storage of CO2, just like the reservoir previously contained hydrocarbons for millions of years.

“As part of the next phase of validation, we will be applying DNV GL’s certification scopes for suitability of the CO2 injection well design and well construction process. We’re excited to be able to bring our competencies to use in this effort to deliver significant emission reductions”.

Klaus Langemann, SVP of Technology & Innovation, Wintershall Dea, said: “Wintershall Dea has been producing from the relevant oil fields in Denmark for decades and already has a high level of knowledge of the reservoir characteristics.

“The Greensand project will further advance Wintershall Dea’s understanding of CCS projects, thus, we are pleased to see the positive outcome of the study which states that there are no showstoppers for futher investigating the storage of CO2”.

It is worth reminding that Wintershall Dea has recently set a goal to achieve net-zero upstream activities by 2030 and ensure there is a mix of renewable and low-carbon energy to tackle the world’s climate change challenge.

In 2019, the company’s operating activities generated around 2.5 million metric tons of CO2 equivalents worldwide.

In addition to targeting net-zero operations by 2030, Wintershall Dea will also reduce its corporate methane intensity to 0.1 per cent by 2025.