A BIODEGRADABLE SET RETARDER FOR A CEMENT COMPOSITION

摘要

Compositions and methods are directed to a cement composition for use in a subterranean formation. In an embodiment the cement composition comprises: (A) cement; (B) water; and (C) a polymer, wherein the polymer: (i) consists essentially of a monomer or monomers selected from the group consisting of acrylic acid, esters of acrylic acid, maleic acid, methacrylic acid, esters of methacrylic acid, itaconic acid, tumeric acid, citraconic acid, mesoconic acid, and any alkali metal, alkaline earth metal, or ammonium salt of any of the foregoing, and any combination of any of the foregoing; (ii) has the following characteristics: (a) is water soluble; and (b) is biodegradable; and (iii) is capable of providing: (a) a thickening time of at least 2 hours for a test composition maintained under a temperature condition of 190 0F and a pressure of 5,160 psi; and (b) an initial setting time of less than 24 hours for the test composition maintained under a temperature condition of 217 °F and a pressure of 3,000 psi, wherein the test composition consists of 860 grams of Class-H Portland cement, 325 grams of deionized water, and 0.4 % by weight of the cement of the polymer. In another embodiment the method comprises the steps of: (A) introducing the cement composition into the subterranean formation; and (B) allowing the cement composition to set after introduction into the subterranean formation.