| abstract |
The present invention relates to a stable aqueous cross-linked copolymer suitable for both high-temperature-high-pressure (HTHP) and non-high-temperature-non-high pressure (HTHP) copolymers for oil and gas applications consisting of the following: (i) a linear cross-linked copolymer The crosslinked, linear copolymer of a poly(vinyl amide/carboxylic acid) has the following structure, by weight, 25-75% vinyl amide monomer selected from vinyl pyrrolidone, vinyl caprolactam, N -vinyl-N-methyl N-vinyl-N-methylacetamide and mixtures thereof, of 25-75% of polymerizable carboxylic acid monomer selected from acrylic acid, (meth)acrylic acid, crotonic acid, itaconic acid, maleic acid and mixtures thereof, and (ii) a cross-linking agent of 0.1-5% based on the weight of the total monomers. A related composition comprising the said copolymer and a method for using |