Perpustakaan Digital ITB

This study presents a Computational Fluid Dynamics (CFD) simulation of drilling fluid flow inside a deviated drillstring geometry to evaluate cuttings transport behavior. Simulations were conducted using water, polymer solutions (0.143%, 0.285%, 0.370%), and foam fluids (80% and 90% quality) under a baseline flow rate of 300 GPM. Key performance indicators such as outlet velocity, pressure loss, and wall shear stress were analyzed to assess each fluid’s hydraulic efficiency and its implications for solids suspension, bed removal, and erosion risk. At 300 GPM, water and all polymer cases exceeded their fluid critical slip velocities, while foam cases did not meet their higher critical thresholds, suggesting flow rate at 300 GPM was not enough for cuttings transport. Their effectiveness varied depending on rheological behavior and physical properties of the cuttings. Water achieved the highest outlet velocity but lacked adequate suspension capability. Polymer fluids, particularly at 0.370% concentration, delivered the best performance due to strong shear-dependent viscosity reduction and consistent flow distribution along the annular wall. In contrast, foam fluids exhibited beneficial shear-thinning behavior and lower pressure loss, but their outlet velocities remained below the critical requirement, resulting in insufficient transport potential at the tested flow rate. The results emphasize the importance of selecting appropriate rheological properties to optimize hole cleaning. Polymer 0.370% is recommended for general applications, while high-quality foam may require higher flow rate.