Numerical Study Of Fluid Flow In Eccentric Annulus

The eccentric annulus flow has found wide applications in petroleum engineering.During the drilling operation,such a flow can have critical influence on the drilling rate,borehole quality and drilling cost.A historical review has been performed in this thesis about the non-Newtonian fluid eccentric flow.The physical model and numerical scheme have been built and the standard k-? turbulence model with wall function have been applied to the simulation.Grid densities have been studied and optimized.The numerical results were validated against PIV measurement available.Unsteady flow simulation was performed to understand the relationship between the fluid flow and pressure distribution against time.And steady flow was simulated to understand the influence of eccentricity,initial fluid velocity and fluid properties on velocity distribution,non-uniformity and pressure loss.Fluid flow within a sudden-expansion flow domain was studied,the fluid velocity distribution,pressure loss and the vortex intensity was analyzed.The relationship between rotational speed,eccentricity,initial velocity and fluid properties and deviation angle,maximum velocity and flow field non-uniformity was analyzed with double-factor variance method.The influence of rotational speed under different fluid condition on the pressure loss of helical flow was studied and the influence of flow index,dynamic gel strength,consistency coefficient and initial velocity on critical rotational speed was analyzed.The program and Analysis Software for Fluid Flow in Annulus was coded with Visual Basic language and the software certification has been issued.The software shows the characteristics of nice GUI,integrated functions and be applied to real drilling condition.