Hydrophobically modified polymers for a well completion spacer fluid

A method of reducing the water permeability of a well bore, comprising:

• introducing into the wellbore a treating fluid for separating a first fluid from a second fluid and for displacing the first fluid from the wellbore in advance of the second fluid, the treating fluid comprising a water soluble relative permeability modifier, wherein the water soluble relative permeability modifier comprises a hydrophobically modified water soluble polymer, the hydrophobically modified water soluble polymer being a reaction product of a hydrophilic reactive polymer and a hydrophobic compound, wherein the hydrophilic reactive polymer comprises a reactive amino group,
• thereby reducing the water permeability of the well bore.

A method of reducing the water permeability of a well bore in a formation, comprising:

• introducing into the wellbore a treating fluid for separating a first fluid from a second fluid and for displacing the first fluid from the wellbore in advance of the second fluid, the treating fluid comprising a water soluble relative permeability modifier, wherein the water soluble relative permeability modifier comprises a hydrophobically modified water soluble polymer, the hydrophobically modified water soluble polymer being a reaction product of a hydrophilic monomer and a hydrophobically modified hydrophilic monomer;
• wherein the hydrophilic monomer is selected from the group consisting of N,N-dimethylacrylamide, vinyl pyrrolidone, dimethylaminoethyl methacrylate, dimethylaminopropylmethacrylamide, vinyl amine, trimethylammoniumethyl methacrylate chloride and hydroxyethyl acrylate, and
• allowing the treating fluid to enter the formation, thereby allowing the water soluble relative permeability modifier to be adsorbed into the formation, which adsorption causes a reduction in the water permeability of the wellbore without substantially reducing the hydrocarbon permeability thereof.

A method of reducing the water permeability of a well bore in a formation, comprising:

• introducing into the wellbore a treating fluid for separating a first fluid from a second fluid and for displacing the first fluid from the wellbore in advance of the second fluid, the treating fluid comprising a water soluble relative permeability modifier, wherein the water soluble relative permeability modifier comprises a hydrophobically modified water soluble polymer is selected from the group consisting of acrylamide/octadecyldimethylammoniumethyl methacrylate bromide copolymer, dimethylaminoethyl methacrylate/hexadecyldimethylammoniumethyl methacrylate bromide copolymer, dimethylaminoethyl methacrylate/vinyl pyrrolidone/hexadecyldimethylammoniumethyl methacrylate bromide terpolymer and acrylamide/2-acrylamido-2-methyl propane sulfonic acid/2-ethylhexyl methacrylate terpolymer;
• and
• allowing the treating fluid to enter the formation, thereby allowing the water soluble relative permeability modifier to be adsorbed into the formation, which adsorption causes a reduction in the water permeability of the wellbore without substantially reducing the hydrocarbon permeability thereof.