In carbon capture and storage (CCS), CO₂ is transported through pipelines at extremely high pressure, taking on properties of both a liquid and a gas in its dense, compressed state. Running ductile fracture (RDF) testing investigates the behaviour of this dense-phase CO₂ within the pipeline and assesses potential outcomes in the unlikely event of a rupture. Below, CCS project lead Anil Erdoğdu explains in clear terms the pipeline testing process and emphasises its critical importance.

Technology plan
“CCS involves the transportation of dense-phase CO₂, which behaves differently from conventional substances such as natural gas. Moreover, it has not been transported at this scale before. Such an innovative approach requires equally innovative methods. To understand how CO₂ behaves under these conditions, we need rigorous testing”, explains Anil. The process begins with a technology plan that identifies required technologies and those needing further development or testing. A primary focus is the technology readiness level (TRL), which determines the qualification process to ensure the technology is fit for purpose. Running ductile fracture (RDF) testing is one such qualification process.

Preparation
RDF testing begins with mathematical simulation models designed to predict how fractures might propagate through a pipeline under stress. Anil says, “These models create a vital theoretical framework, but their accuracy must be validated through real-world testing. Engineers conduct full-scale testing using pipelines identical to those designed for Aramis, employing pipes of varying thicknesses to represent the different sections of the actual pipeline. This approach allows us to evaluate performance across a range of operational conditions, ensuring the pipeline’s safety and integrity.”

Full-scale testing execution
At a specialised and isolated testing facility, the pipeline is pressurised with dense-phase CO₂, and a controlled fracture is initiated. This allows engineers to closely observe the fracture’s behaviour and the potential consequences of a rupture. According to Anil, “RDF testing is not about preventing a rupture altogether but ensuring that, if one does occur, it remains localised. By observing the fracture’s propagation in a controlled setting, we can assess whether the pipeline’s design effectively limits the impact of a rupture.”

Analysis and adjustment
The results are carefully analysed to confirm that the pipeline’s design meets all safety standards. “Any identified weaknesses lead to design adjustments, such as increasing the pipeline’s thickness or adding additional safety measures. It’s an iterative process of testing, analysing and refining”, explains Anil. This cyclical approach ensures that the pipeline can handle the unique challenges of transporting dense-phase CO₂ and, most importantly, that it is safe to do so.

Paving the way
The meticulous approach underscores the Aramis project’s commitment to safety and innovation in the emerging field of CCS. By combining advanced technology with the expertise of international specialists, the project is setting the bar for industry standards. RDF testing not only ensures the safety of the pipeline but also provides valuable insights for the global CCS community. For Anil, this is the most inspiring aspect of her work: “Experts from around the world are collaborating to create an incredible database of knowledge. We are paving the way for future projects to build on this foundation.”