Investigating the Jet Comminuting Process in Cuttings Transport by Coupling the CFD/DEM Method and Bonded-Particle Model

Jet comminuting technology has proved to be an effective means of solid particle pulverization, and current research attempts to introduce it for drilling work to reduce cuttings size, because smaller cuttings are easy to circulate out of the bottom, thus can effectively prevent the formation of cuttings bed, especially in horizontal drilling. In this paper, the feasibility of cuttings' comminution by jet is studied by means of numerical simulation with secondary development. The coupling analysis methods-including the computationalfluid-dynamics/discrete-element-model (CFD/DEM) modeling for the interaction between fluid and cuttings and the particle replacement and bonding modeling for cuttings breakage-are used to characterize the jet comminuting process of cuttings. Input parameters of simulation are reliable and verified by uniaxial compression tests. Case studies presented here indicate that cuttings can be considerably accelerated by 20 to 30 m/s through the throat, which provides a good effective speed for the cuttings. After being accelerated by the fluid and crushed with the target, the vast majority of cuttings results in smaller debris. Also, increasing the inlet speed affects the crushing efficiency. The inclination of the target at near 65 degrees shows good results. This paper proposes a new perspective to introduce the jet comminuting technique for drilling operations, and its findings could help in guiding engineering design in the future.