Permeability-modifying drilling fluids and methods of use

Abstract

Methods of reducing the permeability of a subterranean formation to aqueous-based fluids using a water-soluble relative permeability modifier that comprises a hydrophobically modified polymer, wherein the hydrophobically modified polymer is a reaction product of: a hydrophilic polymer that comprises a polymer selected from the group consisting of a polyvinylamine, a poly(vinylamine/vinyl alcohol), and an alkyl acrylate polymer; and, a hydrophobic compound comprising at least one alkyl chain having a carbon chain length between about 4 and about 22 carbons. The water-soluble relative permeability modifier may be placed within a subterranean drilling operation such that the water-soluble relative permeability modifier attaches onto surfaces within the subterranean formation to effect permeability of aqueous fluids.

Dependencies are inferred from the claim text.