摘要 |
A fracturing fluid composition consisting essentially of a viscous aqueous solution having a high concentration of cations, an anionic or nonionic viscosifier imparting a high viscosity to the composition, and an anionic, polymeric fluid loss material which is substantially insoluble in the aqueous solution, and is soluble in fresh water substantially free of the cations in the fracturing fluid. In the method of fracturing using the fracturing fluid compositions of the invention, the composition is injected into the fracture via the well bore to enlarge and/or extend the fracture. Completion of fracturing is followed by injection of fresh water into the fracture from the well bore to dissolve the anionic, polymeric fluid loss material, and displace the fracturing fluid composition into the formation upon continuation of a water flood operation.
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