Evaluation of drilling fluid removal by cement slurry from horizontal wells with the use of an accurate mathematical model

Cement Placement: An Overview of Fluid Displacement Techniques and Modelling

“…Howard and Clark [7] were probably the first to suggest that a decrease in viscosity of the drilling fluid would increase displacement efficiency. Later the effect of rheological properties of displacing and displaced fluids was studied in various works, such as Flumerfelt [8], Nguyen et al [9], Tehrani et al [10], Miranda et al [11], Aranha et al [12], and Foroushan et al [13]. There were also other investigations, such as the ones of Lockyear and Hibbert [14], Lockyear et al [15], and Silva et al [16], that discussed the effect of yield stress and gel strength of mud on the displacement process.…”

“…There have been more investigators that found that a displacing fluid with a higher density than that of the displaced one improves the cementing operation and the displacement process. Their works include both experiments, such as those performed by Lockyear et al [15], Tehrani et al [10], Miranda et al [11], and analytical methods, such as those developed by Flumerfelt [8], Nguyen et al [9], and Foroushan et al [13].…”

“…For any given flow rate, the stream function Ψ could be obtained through Equations ( 5)-( 7). This would make it possible to obtain the velocity fields via Equation ( 8), and advance the fluids concentration in time by Equation (9). The authors assumed that the fluids were homogeneous across the annular gap and ignored the dynamics of the flow in the vicinity of the interface by scaling laws.…”