Patent ID: 8586511

Claim:
A method for inhibiting scale formation within a hydrocarbon producing system, said method comprising performing a squeeze treatment comprising contacting said system with a copolymer formed from a diallyl ammonium salt of formula (I) wherein R 1 and R 2 are each independently hydrogen or unsubstituted organic radicals having from 1 to 20 carbon atoms; wherein each R is independently selected from hydrogen or organic radicals having from 1 to 20 carbon atoms; and X is a counterion; and at least one anionic monomer of formula (II): wherein R 3 is —CO 2 Z, —SO 3 Z, —PO 3 Z 2 or an alkyl or aryl group -substituted with at least one —CO 2 Z, —SO 3 Z or —PO 3 Z 2 group in which Z is a hydrogen atom or a univalent metal atom; and wherein R 4 , R 5 and R 6 are each independently hydrogen, an optionally substituted alkyl or aryl group having from 1 to 6 carbon atoms, —CO 2 Z, —SO 3 Z, —PO 3 Z 2 or an alkyl or aryl group substituted with at least one —CO 2 Z, —SO 3 Z or —PO 3 Z 2 group in which Z is a hydrogen atom or a univalent metal atom, wherein said copolymer does not comprise acrylamide monomers and said copolymer comprises at least 5 wt % of said diallyl ammonium salt relative to the total weight of monomers, such that scale formation within the hydrocarbon producing system is inhibited by said squeeze treatment, and wherein the copolymer comprises at least one inorganic end group selected from —SO 4 H 2 , —SO 3 H, —H 2 PO 3 , or —H 2 PO 4 , or salts thereof.