Methods of cementing a wellbore with the use of an oil swellable elastomer

Patent metadata

Field	Value
Publication number	US-10557074-B2
Application number	US-201816022981-A
Country	US
Kind code	B2
Filing date	Jun 29, 2018
Priority date	Jun 29, 2018
Publication date	Feb 11, 2020
Grant date	Feb 11, 2020

Abstract

A method of cementing a wellbore penetrating a subterranean formation, the method comprising: injecting into the wellbore an oil-based fluid; injecting into the wellbore a cement spacer fluid comprising an aqueous carrier, an oil swellable elastomer, and a viscosifier; contacting the oil-based fluid with the cement spacer fluid to swell the oil swellable elastomer in the cement spacer fluid; injecting a cement slurry into the wellbore; and allowing the cement slurry to set.

First claim

The invention claimed is:

1. A method of cementing a wellbore penetrating a subterranean formation, the method comprising:
injecting into the wellbore an oil-based fluid;
injecting into the wellbore a cement spacer fluid comprising an aqueous carrier, an oil swellable elastomer, and a viscosifier, the oil swellable elastomer comprising styrene ethylene butadiene styrene, and the viscosifier comprising diutan gum;
contacting the oil-based fluid with the cement spacer fluid to swell the oil swellable elastomer in the cement spacer fluid;
injecting a cement slurry into the wellbore; and
allowing the cement slurry to set,
wherein the cement spacer fluid comprises about 0.5 to about 24 pounds of the oil swellable elastomer per gallon of the cement spacer fluid; and
the weight ratio of the oil-swellable elastomer to the viscosifier is about 95:5 to about 90:10.

2. The method of claim 1 , wherein injecting the cement slurry is subsequent to injecting the cement spacer fluid.

3. The method of claim 1 , wherein the cement spacer fluid prevents mixing of the oil-based fluid with the cement slurry.

4. The method of claim 1 , wherein the oil swellable elastomer in the cement spacer fluid swells forming a barrier between the oil-based fluid and the cement slurry.

5. The method of claim 4 , wherein the oil swellable elastomer is present in the form of particles.

6. The method of claim 5 , wherein the oil swellable elastomer particles have a number average particle size of about 100 to about 1,000 micrometers.

7. The method of claim 4 , wherein the oil swellable elastomer is present in an amount effective to isolate the oil-based fluid from the cement slurry.

8. The method of claim 1 , wherein the aqueous carrier comprises at least water or brine.

9. The method of claim 1 , wherein the oil-based fluid is a drilling fluid.

10. The method of claim 9 , wherein the drilling fluid is all-oil based or a water-in-oil emulsion; and the drilling fluid comprises a diesel oil, a paraffin oil, a vegetable oil, a soybean oil, a mineral oil, an aliphatic solvent, an aromatic solvent, or a synthetic oil, or a combination comprising at least one of the foregoing.

11. The method of claim 1 , wherein the cement slurry sets forming a cement plug.

12. The method of claim 1 , wherein the cement spacer fluid comprises about 1 to about 6 pounds of the oil swellable elastomer per gallon of the cement spacer fluid.

Assignees

• Sodhi Thomas S
• Bryant Shannon E
• Baker Hughes A Ge Co Llc

Inventors

• Sodhi Thomas S
• Bryant Shannon E

Classifications

• C09K8/40 Primary

  Spacer compositions, e.g. compositions used to separate well-drilling from cementing masses · CPC title

• C09K8/32

  Non-aqueous well-drilling compositions, e.g. oil-based · CPC title

• E21B33/16

  using plugs for isolating cement charge; Plugs therefor {(stage cementing E21B33/146; spacer compositions C09K8/424)} · CPC title

• C09K8/424

  using "spacer" compositions · CPC title

• E21B33/138

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