MICROEMULSION-BASED FLUSHING FLUID FOR EFFECTIVE REMOVAL OF FILTER CAKE IN WELLS CEMENTATION

The objective of this work is to evaluate the effective removal of mud cake formed by drilling fluid for microemulsion-based flushing fluid. The microemulsions were prepared with vegetable castor oil, 2%wt KCl as aqueous phase, and nonionic surfactant (Ultranex NP40). Thermal stability, rheological, removal, and wettability inversion were performed to evaluate the performance of the microemulsion-based flushing fluid. Rheological tests showed that microemulsions behaved like Newtonian fluids. The best formulation of flushing fluid was 70% surfactant/25% oil phase/5% aqueous phase, with cloudy temperature at 365.25 K, removal efficiency of mud cake of 84.85 %, and high capability of wettability inversion.