Effect of drillpipe rotation on cuttings transport during horizontal foam drilling

Abstract

In this study, we sought to experimentally investigate the effect of drillpipe rotation on pressure loss and cuttings transport in a horizontal annular pipe by considering both varied foam qualities of 80, 85 and 90 % and foam velocities. Additionally, the influence of foam velocity and foam quality on pressure loss and cuttings transport efficiency was investigated. The experiments were conducted in a flow loop with a 5-m long eccentric annular test section, representing the wellbore, with a 51.8-mm outer pipe and a 16-mm inner pipe that could be rotated up to 150 rpm. It has been observed that pipe rotation has a negligible effect when only foam flows in the annular pipe. Conversely, pipe rotation has a significant effect on the pressure loss and cuttings transport when the cuttings are injected into the annular pipe. Furthermore, with increasing rotational speed, the frictional pressure loss dramatically decreases and the delivered cuttings concentration increases. Moreover, experimental results show that higher foam quality and velocity increased the pressure loss and decreased the delivered cuttings concentration.