Using particle image velocimetry to evaluate the displacement efficiency of drilling mud in horizontal well cementing

For a horizontal well cementing, successful displacement of the drilling mud from the annulus using the cement slurry were paramount for achieving zonal isolation. This study evaluated the displacement efficiency of drilling mud from the annulus by applying particle image velocimetry incorporating the development of a large-scale displacement efficiency device. Displacement efficiency measurements revealed that increasing the injection displacement and reducing the eccentricity cleans up residual drilling mud and significantly improves displacement efficiency. Slurry density significantly affected displacement efficiency, because high- and lightdensity slurries were shown to lead to low velocities and to increase the boundary layer thickness of the drilling mud. High injection displacement swirling flows were found to be more effective for reducing drilling mud adhesion to the casing and wellbore walls. The eccentric annuli tended to result in a narrow channel, which results significantly reducing the displacement efficiency owed to the laminar fluid flow.