Movement, deposition and influence laws of impurities in the product oil pipelines

In order to make a feasible scheme for hydraulic pigging, the deposition and movement laws and influence factors of impurities in product oil pipelines and the effect of impurity deposition on pipelines were studied. The test loop of product oil carrying water and impurity was designed and established to test the deposition and movement laws of impurities and the internal corrosion characteristics in the product oil pipelines with different inclination angles and diameters. Then, the numerical method of Fluent-DEM coupling was used to investigate the movement characteristics of solid particles in the product oil pipeline under different working conditions. The numerical simulation results are in good agreement with the test data. It is indicated that the numerical simulation method is of high reliability. Finally, the deposition characteristics of impurities, the critical movement velocity, the influence factors of deposition characteristics and the effects of impurity deposition on the internal pipeline corrosion were investigated by means of tests and numerical simulation. It is shown that the solid particles are usually deposited behind the elbow of the upward inclined-horizontal pipe. The influence laws of flow velocity, inclination angle and diameter of pipes, and density and sphericity of solid particles on the movement characteristics of solid particles are figured out, and the action mechanism of impurity deposition on the movement of water accumulated below the product oil and the internal corrosion characteristics in the pipeline are clarified.