Investigation of hydrate slurry flow behaviors in deep-sea pipes with different inclination angles

The marine area is the main direction of the development of oil and gas resources in the world. The pipeline transportation technology of natural gas hydrate slurry plays an important role in the exploitation of marine oil and gas and the exploitation of marine gas hydrate resources. In order to study the influence of pipe inclination on pipeline transportation, population balance model based on hydrate particle aggregation dynamics was coupled with the Eulerian–Eulerian two-fluid multiphase flow model to simulate the flow behaviors of hydrate slurry flow in pipes with different inclination angles. In the study, three variables of inclination, flow rate and initial particle size were considered. The results show that tilted pipes are beneficial to hydrate slurry transport rather than harmful. Meanwhile, higher flow rates and lower initial particle sizes are beneficial for promoting the flow safety of hydrate slurry transport. However, the flow pressure drop of the hydrate slurry increases with the increase of the flow rate and the decrease of the initial particle size, which is not conducive to the economics of mining. The research results in this paper can provide reference for the research of hydrate slurry flow safety and parameter guidance for hydrate solid fluidized mining.