Foamed well cementing compositions and methods

A method of cementing a well penetrating a salt containing subterranean formation comprising:

• forming a foamed cement composition;
• placing said foamed cement composition in contact with said salt containing formation;
• and
• permitting said foamed cement composition to set in contact with said salt containing formation to form a hardened mass of cement;
• wherein said cement composition consists essentially of Portland cement, sufficient water to form a pumpable slurry, sodium chloride present in said water in an amount in the range of from about 18% by weight of water to saturation, sufficient gas dispersed in said slurry to produce a foam, a foaming agent present in said composition in an amount in the range of from about 0.25% to about 6.0% foaming agent by weight of water in said composition and a foam stabilizer present in said composition in an amount in the range of from about 0.25% to about 3.0% stabilizer by weight of water;
• said foaming agent is selected from compounds having the general formulae
• H(CH.sub.2).sub.f (OC.sub.2 H.sub.4).sub.3 OSO.sub.3.sup.- Na.sup.+
• and
• H(CH.sub.2).sub.f (OC.sub.2 H.sub.4).sub.3 OSO.sub.3.sup.- (CH.sub.3).sub.2 CHNH.sub.3.sup.+
• wherein f is an integer in the range of from 6 to 10, and
• said foam stabilizer is selected from compounds having the general formulae
• CH.sub.3 O--CH.sub.2 CR.sub.1 HO).sub.n --R.sub.2
• and
• R--CONHCH.sub.2 CH.sub.2 CH.sub.2 N.sup.+ (CH.sub.3).sub.2 CH.sub.2 CO.sub.2.sup.-
• wherein R.sub.1 and R.sub.2 are independently hydrogen or a methyl radical, n is an integer from 20 to 200 and R is a radical selected from decyl, cetyl, oleyl, lauryl and coco.