An interfacial gas-enrichment strategy for mitigating hydrate adhesion and blockage
Rui Ma, Senbo Xiao, Yuanhao Chang, Yuequn Fu, Jianying He, Zhiliang Zhang
Abstract
Unwanted gas hydrates blockage is a threat to the safety of oil–gas pipeline systems. Deploying passive anti-hydrate surfaces is a promising approach to circumventing the long-lasting hydrate problem, and a precise understanding of the interactions between hydrate and solid surfaces is a prerequisite for the creation of such surfaces. In this work, the underlying mechanisms and the key influencing factors of hydrate adhesion are explored by large-scale molecular dynamics simulations. Hydrates with an intermediate layer (IML) containing varied gas content are brought to contact with solid surfaces having different levels of wettability and roughness. It is found that the final IML structure is dictated by the gas concentration. Enriching gas content in the vicinity of solid surfaces is crucial for lowering hydrate adhesion strength. The results indicate that forming a molecular gas layer or gas bubbles on solid surfaces can enable the automatic detachment of the eventually formed hydrate on a pipeline wall surface under the action of shear flow. This study manifests our approach of utilizing an interfacial gas-enrichment strategy (IGES) for weakening hydrate adhesion as a novel passive anti-hydrate surface design.