Numerical study of cuttings transport of nanoparticle‐based drilling fluid

Abstract

Cuttings transportation from the drill bit, through the annulus, to the surface is one of the most important functions performed by drilling fluid. The prediction of drilling fluid's performance to transport cuttings in the annulus is very complex task due to the presence of numerous parameters. Nanoparticles (NPs) have been recently introduced into drilling fluid to engineer its properties and enhance its performance. Nevertheless, the lifting capacity has not been sufficiently investigated. The understanding of the influence and the mechanisms responsible for the improvement in cuttings transport process can further advance the application of NPs for drilling fluids. Computational fluid dynamics (CFD) is widely used as a numerical technique in handling complex multiphase flow problems in different operational conditions. The present work has taken the advantages of CFD to computationally analyze the influence of NPs and the effects of various parameters such as drilling fluids rheology, flow rate, pipe rotation, cuttings density, shape, concentration, and drilling fluids-cuttings particle coupling regimes on the cuttings transport in a vertical wellbore. The CFD simulation is carried out by using transient solver of ANSYS-FLUENT commercial code. The dense discrete phase model is used to overcome the main shortcomings of previous Eulerian based approaches. Good agreement has been achieved between the simulation and the published experimental results. It showed that the fluid viscosity and cuttings transport process can be significantly enhanced by adding nanomaterials to the fluid, and the process is highly influenced by cuttings characteristics such as in situ concentration, shape, and density. K E Y W O R D SCFD, cuttings transport, drilling fluids, multiphase flow, nanoparticles, rheology, wellbore Abbreviations: CFD, computational fluid dynamics; DDPM, dense discrete phase model; DEM, discrete element method; HTHP, high temperature and high pressure; LTLP, low temperature and low pressure

CFD Study of Cuttings Transport in Vertical Rotation Drill Pipe for Multi Muds

“…The outcomes acquired by this model showed that in horizontal annulus and low flow rates of liquid, the pipe rotation becomes more effective by increasing the air flow rate, while the efficiency of cutting transport with the aerated mud reduces by increasing the inclination. Al-Yasiri et al [20] studied the influence of Nanoparticles and the effects of various parameters such as flow rate, pipe rotation, drilling fluids rheology, cuttings density, concentration, shape, and drilling fluids-cuttings particle coupling regimes on the cuttings transport in a vertical wellbore. It showed that the cuttings transport process and fluid viscosity can be significantly enhanced by addition nanomaterial to the fluid, and the process is highly effected by cuttings characteristics such as in shape, situ concentration, and density.…”

Drilling mud upward velocity modelling in Ansys CFX software

“…Further, the initial and boundary conditions are set, i.e. the direction of the entry of the drilling mud into the drill string and its exit through the annular space, the flow rate of the drilling mud is set, the parameters of the mud -viscosity, density, type of mud, rheological model etc [1].…”

Fluid Flow Regimes Analysis on Drilling Fluid Circulation for Cuttings Lifting in Vertical Drilling Oil Wells

“…The drilling process is said to be successful if the cuttings can be lifted to the surface. Therefore, the velocity of the drilling fluid in the annular must be greater than the velocity at which the cuttings falls, so that the velocity at which the cutting rises is obtained from the following equation [6], [12], [14]:…”