Study on the dissolution kinetics of NaCl in environmentally friendly drilling fluids containing glycerin

Abstract The oil well drilling process in the pre-salt layer faces some challenges including the salt dissolution on the drilling muds. The dissolution may be harmful to mechanical processes and drastically change fluid properties. With the increasing research for less aggressive fluids, glycerin from biodiesel production meets technical, economic and environmental requirements for fluids formulation. The aim of this work is the study of dissolution kinetics of NaCl in drilling fluids containing glycerin. Experimental dynamic salt concentration profiles in the liquid phase were obtained in a stirred tank. These data were used to evaluate the mass transfer coefficient in different rotation rates and salt concentrations. The mathematical model simulated the process by the application of the mass conservation equations applied on fluid and solid phases. Through experimental analysis and parameter estimation, the kinetics dissolution was evaluated for two types of glycerin, different rotation speeds and salt concentrations.