Thermostable, watersoluble at high temperatures curable Polymer

摘要

A copolymer comprises structural units derived from 2-acrylamido-2-methylpropanesulfonic acid; N-vinylformamide, N-vinylacetamide, or N-vinyl-N-methylacetamide; cyclic amides, and vinylphoshonic acid or its salt. A copolymer is reversibly crosslinkable with polyvalent metal ions at above 150[deg]C and comprises 80-90 wt.% structural unit(s) of structure -CH 2-C(CONH-R 2>-SO 3->Me +>)R 1>- (A), 1-10 wt.% structural unit(s) of structure -CH 2-C(R 3>-N-CO-R 4>)R 1>- (B), 1-10 wt.% structural unit(s) of structure (C), 0.1-5 wt.% structural unit(s) of structure (D), and optionally, 0-10 wt.% structural unit(s) of structure -CH 2-C[CON(R 5>) 2]R 1>- (E). R 1>H or Me; R 2>2-10C-alkylene; Me +>ammonium or an alkali metal ion; R 3>, R 4>H, Me, or Et; n : 1-6; X : H, an ammonium ion, or an alkali metal ion; R 5>H, Me, and/or Et. The content in the copolymers of structural units B and C is 6-15 wt.%. Independent claims are also included for: (A) a composition comprising the inventive copolymer and a crosslinker containing a compound of a polyvalent metal ion; (B) a process for extracting mineral oil or natural gas from an underground formation having a borehole and the mineral oil or natural gas and water and/or saline water by altering the permeability of the underground formation for water or saline water, comprising introducing simultaneously a crosslinker from at least one polyvalent alkaline earth metal and/or a transition metal compound, and an aqueous solution of the inventive copolymer into the formation at above 200[deg]C; and extracting from the borehole mineral oil or natural gas; and (C) a method for altering the permeability of an underground formation for water or saline water, comprising introducing into the formation at above 200[deg]C a fluid comprising a crosslinker from at least one polyvalent alkaline earth metal and/or a transition metal compound, and the inventive polymer. [Image].