Filling material for underground treatment, underground treatment method and filling well wall method
AssigneeMitsubishi Chemical Corporation
InventorsTakahiro Saka, Masaya Nakai
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Abstract
A filling material for underground treatment of the present invention contains at least one polyvinyl alcohol-based resin of a modified polyvinyl alcohol-based resin and an unmodified polyvinyl alcohol, and a swelling ratio of the polyvinyl alcohol-based resin after immersion in water at a temperature of 80° C. for 30 minutes is 250% to 900%. The filling material for underground treatment has enhanced swelling performance, is effective in preventing phenomena such as lost circulation, and has improved workability of filling a well drilled part with the filling material.
Claims8
An underground treatment method comprising:
- incorporating a filling material for underground treatment into a liquid to be flown into a well that is formed underground, the filling material for underground treatment comprising:
- at least one polyvinyl alcohol-based resin of a modified polyvinyl alcohol-based resin and an unmodified polyvinyl alcohol, wherein
- a swelling ratio of the polyvinyl alcohol-based resin after immersion in water at a temperature of 80° C. for 30 minutes is 250% to 900%;
- provided that the filling material is not added to a cementing fluid or used in a cementing step.
A method for filling a well wall, comprising:
- incorporating a filling material for underground treatment into muddy water near the ground where lost circulation occurs, the filling material for underground treatment comprising:
- at least one polyvinyl alcohol-based resin of a modified polyvinyl alcohol-based resin and an unmodified polyvinyl alcohol, wherein
- a swelling ratio of the polyvinyl alcohol-based resin after immersion in water at a temperature of 80° C. for 30 minutes is 250% to 900%;
- provided that the filling material is not added to a cementing fluid or used in a cementing step.
Dependencies are inferred from the claim text.