| 摘要 |
A grouting composition comprised of (a) 84-95 % by weight of granular water-swellable sodium-based bentonite, (b) 1-8 % by weight of finely divided salt-water hydratable sepiolite, and (c) 4-8 % by weight of a clay stabilizer. The grout composition which contains no organic polymeric substances is mixed with fresh water to provide a pumpable, rehydratable, and easily applied grouting slurry. The slurry admixture will form a solid seal with low hydraulic conductivity and high structural stability. The grouting composition is useful for sealing the annular space around a well casing and plugging abandoned wells in practically all types of formations. A preferred grouting composition comprises 88-90 % by weight of granular sodium bentonite, 6-7 % by weight of sepiolite, and 4-5 % by weight of granular ammonium sulfate. In use, 50 pounds of the preferred grouting composition is mixed with 13-14 gallons of fresh water directly to provide a grouting slurry with a total of 30-32 % by weight of active solids and a density of 10.1-10.3 pounds per gallon. The slurry admixture is a completely inorganic, non-toxic, and environmentally safe grouting system.
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