To achieve energy conservation and emission reduction of heavy oil conveying, a growing number of scholars are devoted to investigating the cold transportation of heavy oil. However, cold transportation also brings the problem of flow assurance in gathering pipelines, i.e., heavy oil adhesion. The occurrence of adhesion behavior in gathering pipelines is inevitably accompanied by multiphase flow, therefore, the mechanism of heavy oil adhesion is elaborated in this study by using multiphase adhesion experiments, interface properties experiments, and molecular dynamic (MD) simulations. It is found that the thickness of the adhesion layer is negatively correlated with the bulk temperature. The formation of the initial adhesion layer (IAL) is initiated by the spontaneous interfacial energy minimization. The development of IAL is caused by the cohesion between IAL and diffused oil droplets. Additionally, it is also found that the decreasing bulk temperature can cause the center of mass of oil droplets to approach the substrate surface and decrease diffusivity of oil droplets, indicating that the intermolecular interaction between oil droplets is enhanced gradually. At the same time, the adhesion layer also becomes thicker and more compact. This study will raise our understanding of the adhesion interaction mechanism in cold transportation of heavy oil which will be beneficial to provide insights into the flow assurance of oilfield surface gathering system.

Experimental and simulation investigation of heavy oil adhesion in cold transportation pipe

ACS Spring Meeting 2021

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