Determination of calcium chloride brine concentration required to provide pressure overbalance

In this study we present an equation of state (pressure–density–temperature dependence) for calcium chloride brine. The empirical coefficients in this equation are expressed as functions of the brine weight concentration (W). Thus for an actual temperature profile and specified downhole pressure the needed brine concentration can be determined. Knowledge of pressure exerted by a brine as function of downhole temperature, vertical depth, and brine concentration in HPHT wells will allow one to control the overbalance levels.