Abstract: A polymeric scale inhibitor composition and a method for inhibiting metal sulfide scale formation in a well are provided. The composition includes 80-82 mol % of a first monomeric unit, where the first monomeric unit is 2-acrylamido-2-methylpropane sulfonic acid (AMPS). The composition also includes 2-18 mol % of a second monomeric unit selected from N-vinyl formamide, N-vinyl pyrrolidone, and diallyl dimethyl ammonium chloride. The composition further includes 2-18 mol % of a third monomeric unit selected from acrylic acid, methacrylic acid, esters of acrylic acid or methacrylic acid with an alcohol having 1 to 4 carbon atoms, and carboxyethyl acrylate. The polymeric scale inhibitors show superior adsorption characteristics on rocks and their subsequent release behavior allows for scale inhibition over extended time periods respectively at a significant volume of coreflood fluids. They are especially suited for downhole application via field scale squeeze treatments.

Abstract: A polymeric scale inhibitor composition and a method for inhibiting metal sulfide scale formation in a well are provided. The composition includes 80-82 mol % of a first monomeric unit, where the first monomeric unit is 2-acrylamido-2-methylpropane sulfonic acid (AMPS). The composition also includes 2-18 mol % of a second monomeric unit selected from N-vinyl formamide, N-vinyl pyrrolidone, and diallyl dimethyl ammonium chloride. The composition further includes 2-18 mol % of a third monomeric unit selected from acrylic acid, methacrylic acid, esters of acrylic acid or methacrylic acid with an alcohol having 1 to 4 carbon atoms, and carboxyethyl acrylate. The polymeric scale inhibitors show superior adsorption characteristics on rocks and their subsequent release behavior allows for scale inhibition over extended time periods respectively at a significant volume of coreflood fluids. They are especially suited for downhole application via field scale squeeze treatments.