Curing Hydrodynamic Instability During Balanced Plug Cementing

Summary It is shown how the flow from pumping cement through an open-ended pipe very quickly changes direction and flows upward. This rapid change in indicates that a diverter tool, which leads slurry perpendicularly out of closed-ended pipe, does not have any function. The placement balanced plug feasible. However, high-density fluid above lighter stable. phenomenon known as Rayleigh-Taylor instability. In principle, to be reasonably stable, interface must horizontal. longer is, more unstable this case. Thus, it difficult, or sometimes impossible, create stable situation deviated well section, especially if section diameter large. Observations show possible modify density differences, thickening time, viscosity differences such success rate can between 40% 60%. Using floatable foundation increased than 95% North Sea applications. use tool described, its performance justified by numerical analysis flow.