Patent ID: 7219735

Claim:
A packer fluid for use in a wellbore containing wellbore fluid, the packer fluid comprising: in a first phase, an aqueous additive fluid adapted for addition to the wellbore fluid; and a non-toxic, environmentally acceptable capping fluid in substantially a second phase, wherein, the additive fluid and capping fluid having different densities, the capping fluid having a density lighter than the additive fluid and the wellbore fluid for locating adjacent a frost penetration layer adjacent a top of the wellbore, the additive fluid being miscible with the wellbore fluid, and the capping fluid being substantially immiscible with the additive fluid and the wellbore fluid; and additives, being at least a corrosion inhibitor, and being dispersible within the additive fluid and the wellbore fluid, and the additives in the additive fluid further being substantially immiscible with the capping fluid, wherein the first phase and the second phase are substantially phase separated.