Methods for improving the distribution of a sealant composition in a wellbore and treatment fluids providing the same

Patent metadata

Field	Value
Publication number	US-10174241-B2
Application number	US-201415033205-A
Country	US
Kind code	B2
Filing date	Feb 18, 2014
Priority date	Feb 18, 2014
Publication date	Jan 8, 2019
Grant date	Jan 8, 2019

Abstract

Methods for forming a fluid seal in a subterranean formation may comprise: providing a treatment fluid comprising an aqueous carrier fluid, a sealant composition, and a crosslinked polysaccharide composition. The treatment fluid is introduced into a wellbore penetrating a subterranean formation and the crosslinked polysaccharide composition is formed into a viscosified gel in the wellbore. The viscosified gel substantially spans the diameter of the wellbore and holds the sealant composition in place. After forming the crosslinked polysaccharide composition into a viscosified gel in the wellbore, forming a fluid seal in the wellbore with the sealant composition.

First claim

What is claimed is the following:

1. A method comprising:
providing a treatment fluid comprising an aqueous carrier fluid, a sealant composition, and a crosslinked polysaccharide composition for providing an initial viscosity in the treatment fluid;
introducing the treatment fluid into a wellbore penetrating a subterranean formation;
forming the crosslinked polysaccharide composition into a viscosified gel in the wellbore, the viscosified gel spanning the diameter of the wellbore, holding the sealant composition in place, and mitigating slumping effects; and
after forming the crosslinked polysaccharide composition into the viscosified gel in the wellbore, forming a fluid seal in the wellbore with the sealant composition.

2. The method of claim 1 , wherein the viscosified gel distributes the sealant composition uniformly across the diameter of the wellbore and holds the sealant composition in place without slumping.

3. The method of claim 1 , wherein the sealant composition comprises a base polymer and an organic crosslinking agent.

4. The method of claim 3 , wherein forming the fluid seal in the wellbore comprises crosslinking the base polymer and the organic crosslinking agent.

5. The method of claim 4 , wherein the sealant composition and the crosslinked polysaccharide composition do not interfere with the crosslinking of each other.

6. The method of claim 3 , wherein the crosslinked polysaccharide composition comprises an inorganic crosslinking agent.

7. The method of claim 3 , wherein the base polymer comprises an acrylamide monomer unit or a derivative thereof.

8. The method of claim 7 , wherein the base polymer comprises a copolymer selected from the group consisting of a partially hydrolyzed polyacrylamide, a copolymer of acrylamide and t-butyl acrylate, and any combination thereof.

9. The method of claim 3 , wherein the organic crosslinking agent comprises a crosslinking polymer selected from the group consisting of polyethyleneimine, polyvinylamine, any derivative thereof, any salt thereof, and any combination thereof.

10. The method of claim 1 , wherein the sealant composition comprises a mixture of crosslinkable monomers, at least a portion of the crosslinkable monomers comprising an acrylate monomer.

11. The method of claim 1 , wherein the crosslinked polysaccharide composition comprises a polysaccharide and a crosslinking agent.

12. The method of claim 11 , wherein the polysaccharide comprises a guar.

13. The method of claim 11 , wherein the crosslinking agent comprises an inorganic crosslinking agent selected from the group consisting of a borate crosslinker, a metal ion crosslinker, and any combination thereof.

14. The method of claim 1 , wherein the wellbore comprises a horizontal section, the treatment fluid being placed in the horizontal section of the wellbore and the fluid seal being formed therein.

15. The method of claim 1 , wherein the treatment fluid is thixotropic.

16. A system comprising:
a pump fluidly coupled to a tubular, the tubular containing a treatment fluid comprising an aqueous carrier fluid, a sealant composition, and a crosslinked polysaccharide composition for providing an initial viscosity in the treatment fluid, the crosslinked polysaccharide composition forming into a viscosified gel in a wellbore and mitigating slumping effects, and the treatment fluid being thixotropic.

Assignees

• Halliburton Energy Services Inc

Inventors

• Eoff Larry Steven
• Reddy B Raghava
• Pascarella Natalie
• Mebratu Amare

Classifications

• C09K8/514

  of natural origin, e.g. polysaccharides, cellulose (C09K8/512 takes precedence) · CPC title

• E21B33/138

  Plastering the borehole wall; Injecting into the formation · CPC title

• C09K8/90

  of natural origin, e.g. polysaccharides, cellulose · CPC title

• C09K8/882

  obtained by reactions only involving carbon-to-carbon unsaturated bonds · CPC title

• E21B21/003

  Means for stopping loss of drilling fluid (plastering the borehole wall E21B33/138) · CPC title