Perpustakaan Digital ITB

Efficient drilling fluid circulation is required to maintain wellbore stability, transport cuttings, and manage formation pressure. In deviated wells, flow behavior becomes progressively asymmetric, resulting in uneven distribution of velocity and pressure, as well as secondary flows such as swirl, which affect hydraulic performance. This study employs Computational Fluid Dynamics (CFD) to simulate water-based drilling fluid circulation under steady-state, single-phase, and isothermal conditions. The modeling was carried out by defining the well geometry, applying appropriate meshing and boundary conditions, and solving the governing equations until convergence. Sensitivity analyses were then conducted on flow rate and inclination angles ranging from 30° to 90°. The study found that cuttings transport requires an outlet velocity of 0.75 m/s, which can only be achieved at flow rates of 300 GPM or above. Pressure loss peaked at 45°, while outlet velocity reached its maximum at 60°, indicating a non-linear trend. Distinct flow features were detected, including jetting near the bit, asymmetric velocity profiles, and swirl-induced turbulence in the lower annulus. These conditions were also associated with potential erosion zones, particularly around the nozzle exit and lower curved sections of the wellbore. The findings contribute to a better understanding of flow dynamics in inclined wells and offer practical guidance for improving drilling fluid circulation design and minimizing erosion risks in complex geometries.