Application of Computational Fluid Dynamics for Investigation the Effect of the Hole Cleaning Parameters in Inclined and Horizontal Wells

Abstract

The increasing global demand has prompted the development of more innovative ways to enhance the drilling of oil wells at lower costs, and avoid operational problems that affect the speed of drilling oil wells. The numerical cuttings trajectories simulation has been done to include the effect of cuttings collisions using commercial ANSYS FLUENT 2019 R3 CFD software. The (Eulerian-Eulerian) model was used to verify the cuts transport behavior due to the existence of liquid and solid phases. In this simulation, the mind transport rate is checked by changing the operational parameters which including (drilling mud flow rate and temperature, cuttings size, inclination, drill pipe rotation and eccentricity). The results show that the high degree of agreement was observed between the numerical results with experimental studied by the researcher Yaacob, indicating the CFD analysis system's dependability and capacity to mimic the drilling operation. The use of (Eulerian-Eulerian) model is found reliable in interpreting the phenomena of multiphase flow for understanding the mechanism of influence of parameters associated with the process of drilling oil wells on the lifting capacity. Increasing the flow velocity of the drilling mud transforms the flow pattern from laminar to turbulent, and the latter is one of the desired flow patterns during the flow that enable to increase the lifting capacity of the cuttings. The effect of the rotation speed of the drill pipe on the concentration of cuttings decreases when the flow rate of drilling fluid increases. the cuttings concentration when the flow velocity is 0.6 m/s reaches 48 % when the cuttings size is (0.5-1) mm and it attained to (60,57.52) % when the cuttings size is ((3.5-4) ,(2.25-3),(1.5-2)) mm respectively for the same flow velocity.  The increase in the temperature of the drilling fluid weakened the ability of the drilling fluid to move the cuttings.  At the flow velocity is 1.2 m/s and the drilling angle is 0˚ (vertical well), the cuttings concentration attained to 30 % within the annular space, while the concentration becomes (41, 44, 54, 32) % at the drilling angle (30˚, 45˚, 60˚, 90˚) respectively at the same stated flow velocity.