US 7,678,742 B2 · Drill-in fluids and associated methods

Abstract

Of the many methods provided herein, the present invention provides a method comprising: providing a drill-in fluid that comprises an aqueous base fluid, a viscosifier, a relative permeability modifier fluid loss control additive, and a degradable bridging agent comprising a degradable material capable of undergoing an irreversible degradation downhole; placing the drill-in fluid in a subterranean formation; and allowing the relative permeability modifier fluid loss control additive to reduce fluid loss from the drill-in fluid to the subterranean formation. Another example is a method of degrading a filter cake in a subterranean formation comprising: providing a filter cake produced by a drill-in fluid that comprises an aqueous base fluid, a viscosifier, a relative permeability modifier fluid loss control additive, and a degradable bridging agent comprising a degradable material capable of undergoing an irreversible degradation downhole; and allowing the degradable bridging agent to degrade.

Claims21

Dependent claims

A method comprising:

providing a drill-in fluid that comprises an aqueous base fluid, a viscosifier, a degradable bridging agent comprising a degradable material capable of undergoing an irreversible degradation downhole, and a relative permeability modifier fluid loss control additive, wherein the relative permeability modifier fluid loss control additive comprises a water-soluble hydrophobically modified polymer comprising a reaction product of a hydrophilic polymer and a hydrophobic compound, wherein the mole ratio of the hydrophilic polymer to the hydrophobic compound is in the range of from about 99.98:0.02 to about 90:10;
placing the drill-in fluid in a subterranean formation;
and
allowing the relative permeability modifier fluid loss control additive to reduce fluid loss from the drill-in fluid to the subterranean formation.

1 more element

A method comprising:

providing a drill-in fluid that comprises an aqueous base fluid, a viscosifier, a degradable bridging agent comprising a degradable material capable of undergoing an irreversible degradation downhole, and a relative permeability modifier fluid loss control additive, wherein the relative permeability modifier fluid loss control additive comprises a water-soluble hydrophobically modified polymer comprising a polymerization reaction product of a hydrophilic monomer and a hydrophobically modified hydrophilic monomer, wherein the mole ratio of the hydrophilic monomer to the hydrophobically modified hydrophilic monomer is in the range of from about 99.98:0.02 to about 90:10;
placing the drill-in fluid in a subterranean formation;
and
allowing the relative permeability modifier fluid loss control additive to reduce fluid loss from the drill-in fluid to the subterranean formation.

1 more element

Dependencies are inferred from the claim text.

Drill-in fluids and associated methods

Life of this patent

Drill-in fluids and associated methods

Life of this patent

Abstract

Claims21