Patent ID: 7608571

Claim:
A method for recovering crude oil from a subterranean formation, comprising introducing to the formation an aqueous fluid comprising: (a) water or brine and (b) an organophosphorus material selected from the group consisting of: (b)(1) organophosphorus compounds according to structure (I): wherein: each R 1 is and each R 2 is independently absent or O, provided that at least one of R 1 and R 2 is O, each R 3 is independently alkyleneoxy, poly(alkyleneoxy), which may optionally, be substituted on one or more carbon atom of such alkyleneoxy, or poly(alkyleneoxy) group by alkyl, alkoxy, alkenyl, aryl, or aryloxy, R 5 is and each R 4 is independently absent or alkyleneoxy, poly(alkyleneoxy), which may optionally, be substituted on one or more carbon atom of such alkyleneoxy, or poly(alkyleneoxy) group by alkyl, alkoxy, alkenyl, aryl, or aryloxy,- R 6 and R 8 are each and each R 7 is independently H, or (C 1 -C 30 )hydrocarbon, which hydrocarbon may optionally be substituted on one or more carbon atoms by fluorine, alkyl, alkenyl or aryl, on one carbon atom by hydroxyl, and/or interrupted at one or more sites by an O, N, or S heteroatom, or —POR 9 R 10 , R 9 and R 10 are each independently alkoxy, aryloxy, or (C 1 -C 30 )hydrocarbon, which hydrocarbon may optionally be substituted on one or more carbon atoms by fluorine, alkyl, alkenyl or aryl and/or interrupted at one or more sites by an O, N, or S heteroatom, and m is an integer of from 2 to 5, (b)(2) salts of organophosphorus compounds according to structure (I), (b)(3) condensation reaction products of two or more molecules of one or more organophosphorus compounds according to structure (I), and (b)(4) mixtures comprising two or more of the compounds, salts, and/or reaction products of (b)(1), (b)(2), and (b)(3).