The Influence of Cuttings Polydispersity on Wellbore Cleaning Operations using the Kinetic Theory of Granular Flow and the Dense Discrete Phase Model

In this study, polydispersed spherical particulate systems are examined using the Eulerian-Eulerian (EE) and Lagrangian-Eulerian (LE) modelling approaches in the context of wellbore cleaning operations in the drilling industry. The particle sizes considered here are between 0.5 mm and 1mm, whereas a Power Law rheological model is used for the fluid phase description. The EE approach implemented herein applies the Kinetic Theory of Granular Flow (KTGF) in ANSYS Fluent® and accounts for the particle size differences by representing them as different phases within the flow domain. In addition, the LE approach (employing the Dense Discrete Phase Model – DDPM) represents this difference with the aid of a size distribution model (the Rosin Rammler model). The findings of our computational experiments show that neglecting the size disparity may lead to severe under/overestimation of key variables such as the pressure drop, and particle deposition tendencies; thus, leading to decreased model performance.