Computational analysis of fluid flow in an annulus for the drilling of oil and gas wells

Abstract

An annulus having 0.5 eccentricity, with the diameters ratio of 0.5, measuring three velocity elements consisted of feebly fluid deprived of non-Newtonian shear thinning elasticity and rotational inner cylinder at 300rpm. At laminar region of flow, concerned by 0.2% solution of CMC (Sodium carbo methyl cellulose), based on polymer, it was observed that near the outer pipe wall, a counter rotating flow was observed which was not evidenced at 9200 Reynolds number. The Non-Newtonian fluid will depict the same effects of rotation having more even axial flow through the annulus alike with the simulated work. In all the cases the maximum tangential velocities will be found in the thinnest gap. With the extreme values of bulk velocities near the inner pipe, the secondary flow circulation with the Newtonian fluid at various Reynold’s No. will be found in the direction of rotation. The rotation did not influence due to turbulence moderations & in the smallest gap region, Non-Newtonian fluid will decrease. At low Reynolds numbers, the flow resistance of both fluids will be raised with rotation & with the analogous of non-rotating flow resistances will also be reduced by increasing Reynolds no. For the same Rossby number, the tangential velocities will be found equal. Numerical simulation for the transportation of cuttings in drilling of oil wells, based on the sliding mesh for rotational pipe with the analogous of grainy flow on the kinetic theory basis. The comportment of the drilling fluid was relied on the power-law model. By comparing the outcomes with the literature experimental data, it has been evidenced that impact of rotated inner pipe follows the similar trend as originated in the experimental data.