Abstract
Flow loops and computational fluid dynamics are the main research approaches for resolving the hole-cleaning problems. Cutting transport phenomena can be considered as a Computational Fluid Dynamic (CFD) model by using Eulerian assumptions for the turbulent liquid-solid flow in concentric annuli. The effect of time along with the main operational characteristics on the hole-cleaning phenomena is not negligible but recent studies have had paid little attention to it. Poor near bit cleaning causes many problems such as bit balling, decline in the rate of penetration, pipe sticking, etc. In addition to the effect of inclination, drill pipe rotary speed, cutting size, nozzle velocity and fluid viscosity as well as the effect of the bit nozzle arrangement on the cutting transport process were discussed. The results demonstrate that at a critical inclination angle of 30 degrees the cutting transport is inefficient. For all sections, the effect of drill pipe rotary speed was negligible at high velocities. In the horizontal section, at low flow rates and high drill pipe rotation speeds, Newtonian viscous fluids or water has no effect on the time needed for initial hole-cleaning butby removing the drill pipe rotation speed in similar conditions, a dramatic influence on time is observed. In inclined annuli, increasing the cuttings size and decreasing the nozzle velocity result in having no cutting in the output. Under critical inclination (30 degrees) the effect of the nozzle angle pattern on the hole-cleaning time is negligible. However, for a vertical annulus, the nozzle angle significantly influences the cutting transport. The best performance is obtained when the nozzle angle was perpendicular to the drill pipe axes. Keywords: Two-phase flow, flow characteristics, CFD, jetting flow.
Highlights
The cutting transport phenomenon is one of the main important subjects in drilling of horizontal and extended reach wells
Materials and Methods This work describes a simulation model built in ANSYS Fluent, together with an experimental setup to study the effect of key parameters such as time, flow rate, cuttings size, etc., on wellbore cleaning in simulated horizontal, vertical and inclined well sections
There is a correlation between the increasing amount of the cuttings and the increasing of the rate of penetration (ROP)
Summary
The cutting transport phenomenon is one of the main important subjects in drilling of horizontal and extended reach wells. Bottom Hole Assembly (BHA), drill pipe rotary speed (RPM), flow rate, rate of penetration (ROP) and drilling fluid properties and inclination are the common factors that can be manipulated and controlled to gain a proper hole .5. Since the investigation and study of the effective drilling characteristics on the bottom hole on a drilling rig is costly, researchers have attempted to study this subject with a variety of approaches such as flow loops and Computational Fluid Dynamics (CFD).[6,7] Usually the cutting concentration, mean bed height and the length of the bed are the main variables that are traced for hole-cleaning efficiency across the annulus.[8,9] Bottom Hole Assembly (BHA), drill pipe rotary speed (RPM), flow rate, rate of penetration (ROP) and drilling fluid properties and inclination are the common factors that can be manipulated and controlled to gain a proper hole .5 Since the investigation and study of the effective drilling characteristics on the bottom hole on a drilling rig is costly, researchers have attempted to study this subject with a variety of approaches such as flow loops and Computational Fluid Dynamics (CFD).[6,7] Usually the cutting concentration, mean bed height and the length of the bed are the main variables that are traced for hole-cleaning efficiency across the annulus.[8,9]
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
