There is about 7800 km of pipeline in the North Sea alone and large portion of the pipeline transport will occur within gas hydrate formation conditions. The costs used to mitigate the hydrate problem consists of 70% of the total flow assurance efforts. The main objective of this basic researcher-type project is to design and develop durable dual-functional anti-gas hydrate surface. The research consists of three main aspects: 1) to advance the fundamental understanding of hydrate-(liquid)-solid interactions; 2) to explore novel designs with top surface layer to suppress the particle deposition and sub-surface layer to fatally weaken the hydrate-solid interface and lower the adhesion; 3) to experimentally demonstrate the dual-functional anti-hydrate surfaces. If successful, the design and preparation of the dual-functional anti-hydrate surfaces will open up a new research area on anti-hydrate materials. The deployment of the new surfaces at critical sections will provide an alternative solution to the next generation flow assurance with great potential for increasing value creation.
In the last project period 01.10.2020 - 30.09.2021 big progresses in understanding and developing low adhesion anti-gas hydrate surfaces have been made. First, since ice and gas hydrate are the same families of foulants to be removed from a solid surface, careful reviews about the strategies to lower the ice adhesion have been made to learn how to lower the hydrate adhesion. Second, large scale atomistic simulations have been carried out and it was found that the gas content at the interface critically determine the hydrate adhesion strength. The higher the gas content to be achieved at the interface the lower the hydrate adhesion strength. For the first time, we found that the lowest hydrate adhesion is about 20% of the corresponding ice adhesion strength. Based on these understandings, new coatings have been designed and developed at NTNU Nanolab. The performance of these new coatings are being investigated and evaluated, and preliminary results look very promising.
Gas hydrate deposition and subsequent plugging represent a significant threat for deep-water natural resource exploration and transport. Deploying passive anti-hydrate surfaces where no external force or energy inputs are needed, is a promising alternative with enormous value creation potentials and positive environmental impact, to replace the costly and eco-unfriendly de-hydrate methods. The ultimate goal of the D’andra project is for the first time to develop and evaluate anti-hydrate surfaces with both deposition-suppressing and super-low adhesion properties, as a candidate material for next-generation flow assurance. The research consists of three main aspects: 1) to advance the fundamental understanding of hydrate-(liquid)-solid interactions; 2) to explore novel designs with top surface layer to suppress the particle deposition and sub-surface layer to fatally weaken the hydrate-solid interface; 3) to demonstrate the dual-functional anti-hydrate surfaces.