CFD-DEM simulation of the hole cleaning process in a deviated well drilling: The effects of particle shape--颗粒学报PARTICUOLOGY

Akhshik, S., Behzad, M., & Rajabi, M. (2016). CFD-DEM simulation of the hole cleaning process in a deviated well drilling: The effects of particle shape. Particuology, 25, 72-82. https://doi.org/10.1016/j.partic.2015.02.008

CFD-DEM simulation of the hole cleaning process in a deviated well drilling: The effects of particle shape

Siamak Akhshik ^a, Mehdi Behzad ^a^*, Majid Rajabi ^b

a Department of Mechanical Engineering, Sharif University of Technology, Azadi Avenue, Tehran, Iran
b School of Mechanical Engineering, Iran University of Science and Technology, Narmak, Tehran, Iran

10.1016/j.partic.2015.02.008

Volume 25, April 2016, Pages 72-82

Received 28 October 2014, Revised 25 January 2015, Accepted 27 February 2015, Available online 31 July 2015, Version of Record 18 February 2016.

E-mail: m_behzad@sharif.edu

Highlights

• Particle-fluid flow in a deviated well drilling was simulated using a CFD−DEM method.

• Irregularly shaped particles were constructed by multi-sphere method.

• Effect of particle shape on particle flow pattern and deposition were analyzed.

• Particle concentration and transport velocity increased with decreasing its sphericity.

Abstract

We investigate the effect of particle shape on the transportation mechanism in well-drilling using a three-dimensional model that couples computational fluid dynamics (CFD) with the discrete element method (DEM). This numerical method allows us to incorporate the fluid–particle interactions (drag force, contact force, Saffman lift force, Magnus lift force, buoyancy force) using momentum exchange and the non-Newtonian behavior of the fluid. The interactions of particle−particle, particle−wall, and particle−drill pipe are taken into account with the Hertz–Mindlin model. We compare the transport of spheres with non-spherical particles (non-smooth sphere, disc, and cubic) constructed via the multi-sphere method for a range of fluid inlet velocities and drill pipe inclination angles. The simulations are carried out for laboratory-scale drilling configurations. Our results demonstrate good agreement with published experimental data. We evaluate the fluid–particle flow patterns, the particle velocities, and the particle concentration profiles. The results reveal that particle sphericity plays a major role in the fluid–solid interaction. The traditional assumption of an ideal spherical particle may cause inaccurate results.

Graphical abstract

Keywords

CFD−DEM method; Deviated well drilling; Particles transport; Two-way coupling scheme; Particle−fluid Interaction

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