26 June 2026

Milestone: the golden weld connects the low- and high-pressure pipelines to the Porthos system.

We have once again reached a significant milestone in the realisation of the Porthos project: the connections of the high-pressure and low-pressure pipelines – a technically complex step requiring preparation, precision and collaboration. These connections fall within the scope of contractor Bonatti. For this specific part of the project, Denys carried out the work on behalf of and in close collaboration with Bonatti. The so-called ‘golden weld’ is one of the most crucial welds in the pipeline route. Additional quality controls apply to this joint; checks on the prepared weld joint and an extra visual inspection ensure that all parameters are closely monitored and that the connection is carried out to the highest standards. The low-pressure pipeline is the collector pipeline that transports the captured CO₂ from the port industry to the compressor station. The high-pressure pipeline transports the pressurised CO₂ from the compressor station to the offshore platform, from where the CO₂ is injected into depleted gas fields beneath the North Sea.

What makes this stage of the construction process so special is – apart from the technology and the work on a building site where a large number of operations are carried out simultaneously – above all the collaboration between the teams from Bonatti, Denys and Porthos, who are pooling their expertise to ensure the project is completed safely, to a high standard and on schedule.

🎥 Curious to see what such a crucial connection looks like in practice? Watch the video below, in which Ayolinde Agunloye (Denys) and Ricardo Castro (Bonatti) explain this important milestone in the project. Porthos is a joint venture between Energie Beheer Nederland, Gasunie and the Port of Rotterdam. The project has been made possible by a CEF grant from the European Commission.