Patent ID: 8091638
Filing Date: 2012-01-10
Classification: C09K,E21B

Abstract:
1. A method of controlling fluid loss in a subterranean formation comprising: providing a treatment fluid comprising an aqueous fluid and a fluid loss control additive comprising a water-soluble polymer having hydrophobic modification, wherein the water-soluble polymer comprises a polymer backbone that comprises polar heteroatoms, and wherein the water-soluble polymer comprises at least one hydrophobically modified polymer that comprises a reaction product between a hydrophobic compound and a hydrophilic polymer wherein the hydrophobic compound is selected from the group consisting of: an anhydride of octenyl succinic acid; an ester of octenyl succinic acid, an amide of octenyl succinic acid, an anhydride of dodecenyl succinic acid, an ester of dodecenyl succinic acid, and an amide of dodecenyl succinic acid and wherein the hydrophilic polymer comprises a reactive amino group in the polymer backbone or as a pendant group, the reactive amino group capable of reacting with the hydrophobic compound; and introducing the treatment fluid into an interval of a well bore penetrating the subterranean formation wherein the water-soluble polymer reduces the permeability of the portion of the subterranean formation to aqueous fluids without substantially reducing the permeability to hydrocarbons so that fluid loss from the aqueous fluid into the portion of the subterranean formation is reduced; creating one or more perforations in the interval of the well bore, wherein the perforations extend from the well bore and into the subterranean formation; and allowing the treatment fluid to contact a portion of the subterranean formation through the one or more perforations.