Density Modeling for Brines as a Function of Composition, Temperature, and Pressure

Abstract

Summary Electrolyte solutions containing high concentrations of salts, such as NaCl, KCl, CaCl2, CaBr2, and ZnBr2, have several important applications in the oil field. The so-called "heavy brines" are used as solids-free completion fluids. Brines are also a major constituent of many drilling-fluid systems, including both water- and oil-based muds. This paper describes the density behavior of brine solutions containing single salts and salt mixtures under various temperature and pressure conditions. Examples are given for using the derived density model to calculate both downhole differential pressures for brine completion fluids and the solids content in brine muds.