Modeling of Drilling Cuttings Transport by Foam in Horizontal Well Condition Using Computational Fluid Dynamics

Abstract

Efficient cuttings transport is one of the most important parameters affecting the drilling rate of wells. Foam has a great potential to reduce drilling problems compared to conventional drilling fluids due to its unique properties such as low density and high viscosity. In this paper, cuttings transport with foam was studied using a computational fluid dynamics approach. In this study, the Eulerian multiphase model was used to describe cuttings-fluid mixture flow. Foam rheology was expressed by the non-Newtonian power-law model. Effects of foam quality and injection velocity, cuttings size, pipe eccentricity and rotational speed of drill pipes were studied. Modeling results were also compared with experimental data. Results showed that the increase of foam quality improved hole-cleaning operation mainly due to the enhanced foam viscosity. The increase in foam injection velocity led to a reduction in in-situ cuttings concentration. This was due to the foam capability to destruct stationary cuttings bed. It was found that pipe eccentricity resulted in the accumulation of cuttings in the annulus. But, an increase of the drill pipe rotational speed provided a better hole-cleaning, so that by increasing the rotational speed to 40 RPM, cuttings concentration decreased by 1.8 and 1.4 times in concentric and eccentric pipe, respectively.