摘要 |
<p>A novel method for making improved cement fluid loss additives comprising copolymers of acrylamide having desirable viscosity and fluid loss control properties. The method combines (1) the use of oxygenated make-up water to dissolve acrylamide monomers, derivatives or mixtures thereof to form a reaction mixture for polymerization of the monomers with (2) a second 'condition' or set of conditions. The second 'condition' or set of conditions is either (a) using of two heating stages to induce polymerization, or (b) adding a small amount of acrylic acid to the reaction mixture before exposing the reaction mixture to a temperature sufficient to polymerize the monomers. The two heating stages of (a) involve (i) an initial, lower temperature stage followed by (ii) a higher temperature stage.</p> |