Aminocarboxylic acid breaker compositions for fracturing fluids

摘要

It has been discovered that aminocarboxylic acids are effective breakers for polymer-gelled aqueous fracturing fluids, particularly in the temperature range between about 120° F. (49° C.) and about 280° F. (138° C.). The aminocarboxylic acids are believed to act directly on the polymer and not to any great extent or not to as an effective extent on a crosslinking agent, if present. The polymer may be a polysaccharide, and the aminocarboxylic acid may be selected from the group including, but not necessarily limited to, tetrasodium ethylenediaminetetraacetic acid (Na₄EDTA), tetrasodium propylenediaminetetraacetic acid (Na₄PDTA), trisodium hydroxyethylenediaminetetraacetic acid (Na₄HEDTA), trisodium nitrilotriacetic acid (Na₃NTA), salts of these acids, and mixtures thereof.