Patent ID: 7238646

Claim:
A method for using an invert emulsion fluid in a well bore, comprising: (a) placing an invert emulsion fluid in a well bore, wherein the invert emulsion fluid comprises: (i) an oleaginous fluid; (ii) a non-oleaginous fluid; and (iii) an emulsifier comprising one or more amines generally represented by the formula: wherein R is a radical selected from the group consisting of abietyl, hydroabietyl, dihydroabietyl, tetrahydroabietyl, and dehydroabietyl, each R′ may be the same or different and is an alkyl having from about 1 to about 3 carbons, each A may be the same or different and is NH or O, and the sum of x and y ranges from about 1 to about 20; and (b) contacting the invert emulsion fluid with an acid solution to reversibly convert the invert emulsion to an oil-in-water emulsion.