Predictive modeling of gas diffusion and solubility in polymers for offshore pipelines
The offshore oil and gas industry is increasingly turning to the use of flexible flowlines and risers for the development of marginal fields in mature regions and in locations without established infrastructure. More recently, the problem of capturing and storing CO2 to mitigate climate change and for enhanced oil recovery has emphasized the need for flexible flowlines that can tolerate high pressures and temperatures. A flexible flowline typically consists of an inner and outer polymer tube (inner lining and outer sheath) separated by helically wound steel armoring.
In collaboration with the company NOV Flexibles a PhD project has been established which will address issues related to transport of CO2 and CO2-containing gases in flexible flowlines. The ultimate goal of the project is a model for the prediction of solubility, diffusion and permeability of gases and gas mixtures in polymers used as liner materials in flexible pipelines for transporting fluids in offshore applications. It is the intention that the model will also account for volumetric properties of the polymer gas mixture (such as polymer swelling). The emphasis for the model will be on its predictive ability and the possibility of gaining physical insight into the processes described (solubility, diffusion, swelling), i.e. going beyond correlation and data-fitting.
There is a large experimental component in the project, where equipment at CERE will be used to measure properties up to 700 bar.