Additive for slurry, drilling mud, and cement slurry

摘要: Provided by the present invention is an additive for a slurry being capable of inhibiting viscosity elevation and dehydration at high temperatures low cost, through use civil engineering construction (for example, drilling mud cement in well drilling. etc.), like. A powdery slurry, containing vinyl alcohol polymer, which has: solubility 25% or less when immersed hot water 60° C. 3 hours; degree saponification least 99.5 mol %; average polymerization 1,500 4,500 less; amount 1,2-glycol linkage 1.8 % less, passing sieve having nominal mesh opening size 1.00 mm.