Simulation Study On The Sediment And Migrant Rules Of Cuttings In Horizontal Well

The great difficulty in oil-gas field developing can be effectively solved by horizontal well,which thus becomes one of the most significant technologies in the current oil-gas development.However,well drilling and mining would be affected when cuttings are deposited into bed in the annulus pipeline as the debris gravity direction is perpendicular to the fluid motion direction.Therefore,sand cleaning of horizontal well is of vital importance to this technology development.This thesis aims to offer a theoretical basis for the sand cleaning technology evolution by conducting a numerical simulation study of cuttings subsidence and migration laws in the process of sand cleaning in horizontal well,by the use of FLUENT numerical simulation software.At first,the thesis analyzed and concluded the change rule of the horizontal well annular flow field under the influence of different continuous pipe eccentricity,fluid flow and viscosity,by conducting numerical simulation of the characteristics of the field.Then,concluding the subsidence law of cuttings in the horizontal well annular flow field by conducting numerical simulation of the fluid and debris two-phase flow,which involves controlling the six parameters of fluid flow and viscosity,debris particle size and content,rotation rate of cleaning tool,and continuous tube eccentricity.At last,concluding the migration form and rule of cuttings bed in horizontal well by conducting the numerical simulation of the migration,which involves controlling four parameters of fluid flow and viscosity,debris particle size and the initial content of cuttings bed.