Aqueous resin compositions and methods for cement repair

摘要

A composition for repairing voids or cracks in a cement sheath or plug comprises an aqueous epoxy resin, a hardener, an alkali-swellable material and an aqueous carrier fluid. The particle size of the alkali-swellable material is preferably smaller than 200 nanometers, thereby allowing the composition to penetrate cracks as small as 60 micrometers. A method for repairing voids or cracks in a cement sheath, thereby restoring zonal isolation, comprises preparing the composition, injecting the composition into voids or cracks in a cement sheath or plug and allowing the composition to viscosify and harden.

主权项

1. A method of repairing faults or cracks in cement sheaths or plugs, comprising the following steps:
i) preparing a sealant composition comprising:
a) an aqueous epoxy resin dispersion;b) a hardener;c) an alkali-swellable material;d) a pH buffer; ande)an aqueous carrier fluid; ii) injecting the composition into a crack or fault in the cement; and iii) allowing the composition pH to increase upon exposure to the cement, thereby causing the composition to viscosify and harden, thereby restoring zonal isolation, wherein the alkali-swellable material does not swell until the composition enters the crack or fault in the cement.