Methods and aqueous based wellbore fluids for reducing wellbore fluid loss and filtrate loss

Patent metadata

Field	Value
Publication number	US-9896610-B2
Application number	US-99101509-A
Country	US
Kind code	B2
Filing date	May 4, 2009
Priority date	May 5, 2008
Publication date	Feb 20, 2018
Grant date	Feb 20, 2018

Abstract

Embodiments disclosed herein relate to aqueous based wellbore fluids for preventing wellbore fluid loss downhole containing at least one copolymer formed from at least one natural polymer monomer and at least one latex monomer, and an aqueous base fluid.

First claim

What is claimed:

1. A method for drilling a wellbore comprising:
introducing an aqueous based wellbore fluid into the wellbore;
circulating the aqueous based wellbore fluid while drilling,
wherein the aqueous based wellbore fluid comprises a copolymer of a natural polymer and a latex monomer;
wherein the natural polymer is at least one of polysaccharides or tannins and mixtures and derivatives thereof; and
wherein the latex monomer comprises at least one selected from the group consisting of styrene, butadiene, isoprene, vinyl acetate, vinyl esters of fatty acids, vinyl chloride, vinylidene chloride, tetrafluoroethylene, and polymers or copolymers thereof; and
allowing the copolymer to form at least part of a filtercake on the wellbore walls.

2. The method of claim 1 , wherein the copolymer is added as a polymer solution or a polymer suspension to the wellbore fluid.

3. The method of claim 1 , wherein the natural polymer is at least one of tannins, starch, glycogen, cellulose, locust bean gums, xanthan gums, wellan gums, scleroglucan gums, guar gums, and mixtures and derivatives thereof.

4. The method of claim 3 , wherein the natural polymer is at least one of corn starch, cellulose, potato starch, tapioca starch, wheat starch and rice starch.

5. The method of claim 1 , wherein the copolymer provides an effective filtration control at downhole temperatures greater than 300° F.

6. The method of claim 5 , wherein the copolymer provides an effective filtration control at downhole temperatures greater than 350° F.

7. The method of claim 6 , wherein the copolymer provides an effective filtration control at downhole temperatures greater than 400° F.

8. The method of claim 1 , further comprising at least one weighting agent.

9. The method of claim 1 , wherein the copolymer is incorporated into the wellbore fluid in an amount up to 20 weight percent.

10. The method of claim 1 , wherein the aqueous based wellbore fluid further comprises at least one of viscosifiers, wetting agents, corrosion inhibitors, oxygen scavengers, anti-oxidants and free radical scavengers, biocides, surfactants, dispersants, interfacial tension reducers, pH buffers, mutual solvents or thinning agents.

11. The method of claim 1 , further comprising:
removing the filtercake from the wellbore walls by
emplacing a breaker fluid into the wellbore to allow the breaker fluid to contact the filtercake comprising the copolymer.

Assignees

• Young Steven
• Stamatakis Emanuel
• Mi Llc

Inventors

• Young Steven
• Stamatakis Emanuel

Classifications

• C09K8/12

  containing synthetic organic macromolecular compounds or their precursors · CPC title

• C09K8/508

  macromolecular compounds {(C09K8/512 takes precedence)} · CPC title

• C09K8/5751

  Macromolecular compounds (C09K8/5756 takes precedence) · CPC title

• C09K8/08 Primary

  containing natural organic compounds, e.g. polysaccharides, or derivatives thereof · CPC title