This is a collaborative development initiated by Wintershall Noordzee and includes the OTH Regensburg University of Applied Sciences in Germany.
It involves large-scale CO2 pipeline testing of running fracture in submerged (water) condition, and a comparison with similar testing of the pipe in open air.
The main aim is to quantify the potential beneficial effect of the water surrounding the pipeline on the crack arrest behavior for a specific pipeline, thereby improving definition of the model parameters used for different backfill types.
Early simulation results using numerical models suggest that running fracture in pipelines transporting dense phase CO2 might be easier arrested in submerged conditions compared with in air.
Klaus Langemann, senior vice president Carbon Management and Hydrogen at Wintershall, said: “We are optimistic about the further investigations. Our calculations already show that existing offshore pipelines could be well suited for transporting liquid CO2.
“The next step will be to demonstrate the reliability of the evaluation process and prove the feasibility experimentally.”
Large-scale testing of the CO2 pipelines will take place at DNV’s Testing and Research Facility at Spadeadam in northwest England. Wintershall will provide the design of the fracture arrest test and test-set up, with guidance from OTH and DNV, followed by interpretation of the results.
Currently there are plans for two large-scale tests in air and submerged in water (>5 m/16.4 ft depth), with an option for testing the pipeline buried in soil.
The project should provide validation of the effect of having the pipeline submerged in water in terms of arresting a running ductile fracture. Over the longer term, the project should help validation of numerical models for running ductile fracture.
Prajeev Rasiah, executive vice president for Energy Systems, Northern Europe at DNV, said: “The need to transport CO2 is expected to increase significantly in the years to come as part of the widespread view that carbon capture and storage is a viable means to reduce CO2 emissions. The opportunity, in this instance of repurposing existing subsea pipelines, is a good example of this.
“There are over 4,800 km [2,982 mi] of pipelines in the southern North Sea, of which approximately 1,200 km [745 mi] are operated by Wintershall Noordzee and multiple depleted reservoirs which can be repurposed for CO2 storage.”