Primary cementing is a critical well construction operation that should ensure annular zonal isolation over the life cycle of the oil well. Efficient conditioning and mobilisation of mud prior to cementing is important to ensure that residual mud, especially in washout zones, does not contaminate the cement slurry. Therefore, experiments are carried out to better understand the flow dynamics and associated phenomenon in irregular geometry.
The narrow annulus between casing and formation is approximated by a rectangular slot, in order to aid instrumentation and data acquisition purposes. This methodology can be justified to reproduce flow in narrow annuli fairly well, and is considered a very useful technique for measurement in narrow geometries.
Particle image velocimetry (PIV) is used to obtain the liquid velocity profiles in regular and irregular sections of the experimental setup. Analysis of velocity profiles and vector fields provides information on regions of flow in the vicinity of the irregularity, and this allows a systematic study on the effects of flow rate in regular and irregular wellbore geometries. Entry effects from regular to irregular section and the development of areas with recirculation zones are investigated in irregular section. This enables us to estimate variability of circulation efficiencies in the irregularity. The experimental results are compared with numerical simulations in corresponding irregular geometry.