Patent ID: 6959767

Claim:
A method for treating the sustained casing annulus pressure in a casing annulus of a subterranean well, wherein the casing annulus contains a casing annulus fluid, the method comprising: injecting into the casing annulus a viscosified brine, wherein the viscosified brine has a density greater than the density of the casing annulus fluid and wherein the viscosified brine includes a viscosifying additive selected from the group consisting of: xanthan gums; scleroglucan; hydroxyethyl cellulose (HEC); starch; poly(ethylene glycol)(PEG); poly(diallyl amine); poly(acrylamide); poly(aminomethylpropylsulfonate[AMPS]); poly(acrylonitrile); poly(vinyl acetate); poly(vinyl alcohol); poly(vinylamine); poly(vinyl sulfonate); poly(styryl sulfonate); poly(acrylate); poly(methyl acrylate); poly(methacrylate); poly(methyl methacrylate); poly(vinylpyrrolidone); poly(vinyl lactam); co-, ter-, and quater-polymers of the following co-monomers: ethylene, butadiene, isoprene, styrene, divinylbenzene, divinyl amine, 1,4-pentadiene-3-one (divinyl ketone), 1,6-heptadiene-4-one (diallyl ketone), diallyl amine, ethylene glycol, acrylamide, AMPS, acrylonitrile, vinyl acetate, vinyl alcohol, vinyl amine, vinyl sulfonate, styryl sulfonate, acrylate, methyl acrylate, methacrylate, methyl methacrylate, and vinylpyrrolidone, vinyl lactam; and mixtures and combinations thereof.