CO₂ Safe&Sour Joint Industry Project

Background
The project is working to establish limits for H2S in the prepressed phase CO₂ for CCS pipelines. H2S in combination with H2O and other impurities can lead to sulphide stress corrosion and fracturing of pipeline steels. Therefore, there are currently strict limits on the H2S concentration in the CO₂ stream. Removing H2S from the CO₂ stream is a costly link. The project investigates whether CCS can be made cheaper and more accessible by increasing the limit for H2S.
In the project, experimental testing is being carried out to map the relationship between H2S concentration and stress corrosion. It is also investigated whether an increase in H2S concentration has an impact on general corrosion. IFE, Wood and DNV USA are also contributing to the project.

Goal
The aim of the project is to establish new knowledge about the implications of H2S in CO₂ pipelines and establish limit values for H2S concentration. Recommendations from the project will be used to update DNV’s Recommended Practice DNV-RP-F104 Design and operation of carbon dioxide pipelines.

Activities
The project is run as a Joint Industry Project (JIP) where the focus is to develop recommendations related to H2S level. Important tools are experimental data from tests and understanding of the mechanisms that drive the failure modes. Lab experiments are therefore being carried out in the project, and there is a strong focus on planning and designing tests that help provide recommendations for pipeline operation. Here the focus is on gathering the professional expertise from the various participants and agreeing on which practices should apply to the industry.

What has the project achieved?
In the project we have developed test procedures to map the basic mechanisms that lead to sulphide stress corrosion. The experimental work is ongoing, and recommendations are being worked on that can be given based on the test results obtained so far in the project.

The way forward
Complete the testing planned in the project and continue work in “phase 2” of the project that was started based on the project supported by the project. In phase 2 of the project, we have included several industry participants from the entire CCS value chain. New participants for phase 2 are ExxonMobil, Woodside, ArcelorMittal, Vallourec, Subsea7, Tenaris and Corinth.