METHOD FOR ACIDIZING SUBTERRANEAN FORMATIONS

摘要

Gelled acidic compositions suitable for either matrix-acidizing or fracture-acidizing of subterranean formations, and methods of using said compositions in acidizing operations, are provided. Said compositions comprise water, a water-dispersible biopolysaccharide, an acid, a water-soluble compound of a polyvalent metal wherein the metal can be reduced to a lower polyvalent valence state and cause gelation of the water containing said biopolysaccharide and said acid, and a reducing agent capable of reducing said metal and causing said gelation.