Title: The effect of orbital motion and eccentricity of drill pipe on pressure gradient in eccentric annulus flow with Newtonian and non-Newtonian fluids

Authors: Hicham Ferroudji; Ahmed Hadjadj; Titus Ntow Ofei; Mohammad Azizur Rahman

Addresses: Laboratory of Petroleum Equipment's Reliability and Materials, Hydrocarbons and Chemistry Faculty, M'Hamed Bougara University, Boumerdes, Algeria ' Laboratory of Petroleum Equipment's Reliability and Materials, Hydrocarbons and Chemistry Faculty, M'Hamed Bougara University, Boumerdes, Algeria ' Department of Geoscience and Petroleum, Norwegian University of Science and Technology, S.P. Andersens veg 15a, 7031 Trondheim, Norway ' Department of Petroleum Engineering, Texas A&M University at Qatar, Qatar

Abstract: The correct prediction of the pressure gradient is the fundamental parameter to establish an effective hydraulics program, which enables an optimised drilling process. In the present work, the effect of the orbital motion of the drill pipe on the pressure drop in an eccentric annulus flow with Newtonian and non-Newtonian fluids is studied numerically for both laminar and turbulent regimes using finite volume method (FVM). Furthermore, the effect of eccentricity when the inner pipe makes an orbital motion is evaluated. Different behaviours are observed in laminar and turbulent regimes. In the laminar regime, the simulation results showed that an increase of the orbital motion speed causes a considerable increment of the pressure gradient for the Newtonian fluid. For the power-law, non-Newtonian fluid in the laminar regime, on the contrary, a decrease of the pressure gradient is observed due to the shear-thinning effect. In the turbulent regime the mentioned trends are predicted to be much weaker. As eccentricity increases, the pressure drop of the non-Newtonian fluid decreases with a more pronounced diminish in pressure drop when the drill pipe is in orbital motion for both laminar and turbulent flow regimes.

Keywords: computational fluid dynamics; CFD; pressure drop; orbital motion; laminar flow; turbulent flow.

DOI: 10.1504/PCFD.2020.108520

Progress in Computational Fluid Dynamics, An International Journal, 2020 Vol.20 No.4, pp.238 - 247

Received: 28 Nov 2019
Accepted: 04 Mar 2020
Published online: 15 Jul 2020 *

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