Study On The Migration Of Impurities At The Low Locations Of The Pipeline

There are a large number of particle impurities in a oil pipeline,especially at the low locations of the bends.Particle impurities can block up the pipe fitting and water also accumulated at the low locations,which severely disrupted the safe operation of a pipeline.There are many sediment particles in the early pipelines,oil field pipelines,and subsea pipelines.So it is very important to study the movement of sediment particles at the low locations of the bends.This study measured the particle's size by laser particle size analyzer,in order to establish numerical models,this study analysis the multiphase and turbulence models,on that basis,eulerian model and realizable k-?model were selected,then this study research the movement of particles at the low locations of the bends by using the fluent simulation software.Studying on the movement of sediment particles under different factors,the velocity and distribution of the granular layer was taken as the reference object to analyze the impact of various factors.the results show that:the moving velocity of particles is positively correlated to oil flowing velocity and negatively correlated to particle size;according to the relationship between the angle and the speed,this study provide the basis for selecting pipe bend angle.In analysis of the influence of two-phase flow on the particles,based on the distribution of sediment particles that affected by two-phase flow,this study conclude the influence of two-phase flow on the particles under different factors;when the particles are strongly affected by the secondary flow,most of the particles move forward around the pipe wall.At last,this study analyzed the data fitting and orthogonal test on different factors.In analysis of data fitting,under different influence factors,the simulation results of pressure gradient and velocity were fitted,so this study get seven function formula.Moving speed of particles vary linearly with particle size,but moving speed of particles has exponential relation with oil flow velocity and angle of dip,pressure gradient has exponential relation with oil flow velocity and angle of dip,particle size.This study also verified the correctness of these functions.In orthogonal test analysis,at first,L₉?3⁴?was used as the orthogonal test table,pressure drop in pipeline and the movement of granular layer were taken as test index,orthogonal test was carried out based on oil flow velocity and angle of dip,particle size with three levels,so this study determined the effect of each factor on the test index and the better scheme...