Hole Cleaning in Horizontal and Highly Deviated Wellbores Drilled with Coiled Tubing: Drillpipe Rotation Drawback Is It Significant?
International Research Journal of Engineering and Technology (IRJET)
Coiled tubing (CT) has been recently applied for frequent drilling operation. Pushing the limits for coiled tubing drilling to include extended reach drilling is opposed by hole cleaning issues. Hole cleaning problems are claimed to be critical in coiled tubing drilling due to lack of drillpipe rotation. This paper is intended to show how significant is the effect of not rotating the inner pipe on hole cleaning during coiled tubing drilling. The drillpipe was constrained at its ends only
... ts ends only allowing it to exhibit eccentricity at the mid-section. This allows to simulate the whirling motion of the drillpipe which is claimed to add to good hole cleaning. The effect of pipe rotation was studied and the data collected were graphically correlated in the form of weight percent of recovered particles versus hole inclination at different drillpipe rotational speeds and annular fluid velocities. Results showed that pipe rotation significantly improve hole cleaning; up to 68% improvement was recorded for intermediate velocities (1.86 ft/sec & 2.29 ft/sec). The effect of pipe rotation is less significant at lower annular velocities and lower inclinations (1.43 ft/sec and 60 degree from vertical respectively); however, it has a significant effect at intermediate annular velocities but this effect is diminished with further increase in velocity. The results emphasized that turbulent flow are critical for cuttings removal at horizontal/highly deviated wellbores.