The basic ingredient of calcium chloridecalcium bromide brines
(CaCl2/CaBr2) is a calcium bromide solution that ranges in density from 14.1 to 14.3 ppg (1.72 SG); the pH range is 7.0 to 7.5. The density of CaBr2 brine can be increased by adding calcium chloride pellets or flakes. However, a 1.81 S.G. CaCl2/CaBr2 solution crystallizes at approximately 65°F (18°C). CaCl2 /CaBr2 brine can be diluted by adding a CaCl2 brine weighing 11.6 ppg (1.39 SG). The corrosion rate for CaCl2/CaBr2 is no more than5 mm per year on N-80 steel coupons at 300°F (149°C). If a corrosion inhibitor is desired, a corrosion inhibitor microbiostat is recommended.
The viscosity of CaCl2 /CaBr2 brine can be increased by adding liquefied HEC viscosifier. Reduction in filtration may be obtained by the addition of CaCO3 weighting material/bridging agent or by increasing the viscosity with polymeric materials.
There is not much of a crystallization problem with calcium chloride/ calcium bromide brines at densities between 11.7 and 13.5 ppg 1.40 and
1.62SG. However, the heavier CaCl2/CaBr2 brines require special formulation in cold weather applications.
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