Simulations of Deposition Rate of Asphaltene and Flow Properties of Oil-Gas-Water Three-Phase Flow in Submarine Pipelines by CFD

摘要

Deposition of asphaltenes can occur in the tubing, pipelines and surface facilities leading to operational problems and loss in production. Nevertheless, accurate predictions of asphaltene instability have been elusive. Therefore, simulations of oil-gas-water three-phase flow in different structural pipelines are presented using 3D Computational Fluid Dynamics to get the distribution of each phase and the deposition rate of asphaltene. Calculation results show that flow velocity increases with the reduction of the effective cross-sectional area of the pipe, which leads to its vibration and shorter service life. In the other hand, pressure and temperature in the shrunken effective cross-sectional area decrease with the increase of velocity, intensifying the asphaltene deposition and transportation difficulty. Impact of deposition in bend and sudden changed pipelines is greater than that in straight ones. The calculation results of this paper can provide a guide for safe design and transportation of heavy crude oil in submarine pipelines.