North Sea gas wells ready for CO2 storage as part of Dutch Porthos project

February 5, 2026, by Nadja Skopljak

Four North Sea gas production wells have officially been converted to CO2 injection wells as part of the Port of Rotterdam CO2 Transport Hub and Offshore Storage (Porthos) project in the Netherlands, marking their readiness for CO2 injection, expected in autumn.

Source: Porthos CO2 Transport and Storage C.V.

This first large-scale CO2 transport and storage project to be realized in the EU and the first offshore carbon capture and storage (CCS) project in the Netherlands is designed to transport CO2 captured from industry through the Port of Rotterdam to depleted gas fields in the North Sea, approximately 20 kilometers off the coast, where it will be permanently stored at a depth of more than 3 kilometers beneath the seabed.

It was reported today, February 5, that the conversion of four existing gas production wells on the P18-A platform had been completed, meaning that the wells are ready for CO2 injection to begin once the conversion of the P18-A platform is complete.

The Valaris123 jack-up drilling rig performed the conversion, with TAQA, the former owner of the platform and wells during the gas production period, as the main contractor.

To technically modify the wells to their new function, a new production system was designed and installed.

According to Porthos, the conversion took place in several phases. First, the reservoir was secured at great depth by placing an isolation plug above it, so that no more natural gas could rise. The well was then filled with liquid for extra safety and to clean it. After that, the existing pipes and installations were disconnected and removed from the well. Materials that were still suitable were reused in other projects where possible.

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The condition of each well was checked by lowering ultrasonic measuring equipment on an electric cable to examine the quality of the steel and cement in particular. Once it had been established that the wells were in good condition, new pipes and equipment were installed. Finally, new production valves were installed.

Three other wells have been sealed and permanently removed, two outside the platform, and one well from the platform. The reservoirs into which the injection will take place have remained untouched.

Work on the platform and onshore is set to continue in the coming period, with the first CO2 injection planned for autumn.