Abstract: A problem to be solved of the present invention is to provide a diverting agent which gradually dissolves in water. The present invention relates to a diverting agent containing a polyvinyl alcohol-based resin and a method of filling a fracture using the diverting agent.

Abstract: A problem to be solved of the present invention is to provide a diverting agent which gradually dissolves in water. The present invention relates to a diverting agent containing a polyvinyl alcohol-based resin and a method of filling a fracture using the diverting agent.

Abstract: The diverting agent of the present invention contains resin particles of polyvinyl alcohol-based resin. The resin particles of polyvinyl alcohol-based resin are a particle mixture containing two or more types of resin particles having different particle diameters, and the diverting agent contains resin particles A of polyvinyl alcohol-based resin having a particle diameter of 1,700 ?m or more in a range of 5 mass % to 95 mass % and resin particles B of polyvinyl alcohol-based resin having a particle diameter of 250 ?m to 1,000 ?m in a range of 5 mass % to 95 mass %.

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.

Abstract: An object of the present invention is to provide a diverting agent that can exhibit sufficient filling properties against a fracture in a well in an excavation method using a hydraulic fracturing method, and that is excellent in solubility after a predetermined period of time has passed. The diverting agent of the present invention contains a polyvinyl alcohol-based resin having an average polymerization degree of 1000 or more.

Abstract: An object of the present invention is to provide a diverting agent that exhibits sufficient filling properties against a fracture in a well because of swelling without completely dissolution for a certain period of time (about 30 minutes to 5 hours), and that quickly dissolves and be removed even at a low temperature of 40° C. to 60° C. after a certain period of time has passed. The present invention relates to a diverting agent containing a modified polyvinyl alcohol-based resin.

Abstract: An object of the present invention is to provide a diverting agent that does not completely dissolve for a certain period of time (about 5 minutes to 3 hours) and has high cohesiveness between particles. The present invention relates to a diverting agent containing a polyvinyl alcohol-based resin having a degree of saponification of 65 mol % to 95 mol %.

Abstract: The present invention provides a filling material for underground treatment, which has excellent 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. The 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%.

Abstract: The diverting agent of the present invention contains resin particles of polyvinyl alcohol-based resin. The resin particles of polyvinyl alcohol-based resin are a particle mixture containing two or more types of resin particles having different particle diameters, and the diverting agent contains resin particles A of polyvinyl alcohol-based resin having a particle diameter of 1,700 ?m or more in a range of 5 mass % to 95 mass % and resin particles B of polyvinyl alcohol-based resin having a particle diameter of 250 ?m to 1,000 ?m in a range of 5 mass % to 95 mass %.

Abstract: A problem to be solved of the present invention is to provide a diverting agent which gradually dissolves in water. The present invention relates to a diverting agent containing a polyvinyl alcohol-based resin and a method of filling a fracture using the diverting agent.

Abstract: A cement admixture includes a crosslinked product of a modified polyvinyl alcohol-based resin, wherein the dissolution rate of 1 g of the crosslinked product of a modified polyvinyl alcohol-based resin for 1 liter of water at 70° C. is 50% or less.

Abstract: Conventional methods suffer from unsatisfactory performance of the dehydration-preventing agent at a high temperature, and the present invention provides a cement admixture exhibiting an excellent dehydration-preventing effect at a high temperature. The cement admixture of the present invention includes a crosslinked product of a modified polyvinyl alcohol-based resin, wherein the dissolution rate of 1 g of the crosslinked product of a modified polyvinyl alcohol-based resin for 1 liter of water at 70° C. is 50% or less.

Abstract: Disclosed is a dispersing agent for agrochemicals, said dispersing agent which comprises a modified polyvinyl alcohol-based resin containing a structural unit having a nonionic hydrophilicity group in side chain, and having a saponification degree of 95 mol % or more. The dispersing agent for agrochemicals can provide a dispersion in which a hardly water-soluble agrochemical active ingredient employed for a dispersoid is dispersed in a stable state even in the case where the dispersoid has a relatively large particle size.

Abstract: Disclosed is a dispersing agent for agrochemicals, said dispersing agent which comprises a modified polyvinyl alcohol-based resin containing a structural unit having a nonionic hydrophilicity group in side chain, and having a saponification degree of 95 mol % or more. The dispersing agent for agrochemicals can provide a dispersion in which a hardly water-soluble agrochemical active ingredient employed for a dispersoid is dispersed in a stable state even in the case where the dispersoid has a relatively large particle size.