| 摘要 |
PROBLEM TO BE SOLVED: To provide a slurry composition for excavation of geothermal wells, having stable slurry characteristics and stably keeping its function for the excavation for extended periods at a bed temperature of 250 to 350 deg.C in a well, and also to provide a method for excavating geothermal wells. SOLUTION: This slurry composition is basically composed of natural bentonite either individually or in combination with synthetic smectite and/or synthetic mica, suspended in water, wherein the basic composition is incorporated with dispersant and thickening aid to allow the slurry composition to stably exhibit slurry function at high temperature of 250 deg.C or higher, and to be changed depending on bed temperature.
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