Abstract
Borehole cleaning is a major concern in well drilling which significantly relevant to the drilling cost and safety. In this work, the bottom-hole cleaning performance of swirling jet induced by a drill bit nozzle was discussed. Computational fluid dynamics (CFD) simulations of cuttings transport have been conducted in a full three-dimensional, unsteady multiple-Euler framework by means of the commercial software ANSYS-FLUENT. A detailed comparison, including velocity and pressure fields, Reynolds numbers, cuttings trajectory and volume fraction variation has been made based on the simulation results. The results indicate that swirling jet showed bad bottom-hole cleaning performance compared with straight jet with conventional drilling control parameters. That is, the peculiar properties of swirling jet such as higher turbulent level and entrainment did not cause more efficient removal of drilled cuttings. Relevant conclusions are helpful to promote thorough understanding of the use of swirling jets.
NSTL