Methods of preventing emulsification of crude oil in well bore treatment fluids

Patent metadata

Field	Value
Publication number	US-9051508-B2
Application number	US-201213649156-A
Country	US
Kind code	B2
Filing date	Oct 11, 2012
Priority date	Oct 16, 2007
Publication date	Jun 9, 2015
Grant date	Jun 9, 2015

Abstract

Of the many compositions and methods provided herein, one method includes a method of preventing emulsification of crude oil into an aqueous-based treatment fluid, comprising: contacting crude oil in a well bore with the aqueous-based treatment fluid comprising a styrene-acrylate copolymer, wherein the crude oil has an API gravity of about 10 or greater; and allowing the styrene-acrylate copolymer to interact with the crude oil in the well bore.

First claim

What is claimed is:

1. A method of preventing emulsification of crude oil into an aqueous-based treatment fluid, comprising:
contacting crude oil in a well bore with the aqueous-based treatment fluid comprising a styrene-acrylate copolymer, wherein the aqueous-based treatment fluid has a density of about 12 pounds per gallon to about 18 pounds per gallon, wherein the crude oil has an API gravity of about 10 or greater; and
allowing the styrene-acrylate copolymer to interact with the crude oil in the well bore; wherein the crude oil is not emulsified.

2. The method of claim 1 , the method further comprising screening the crude oil from the aqueous-based treatment fluid.

3. The method of claim 1 further comprising monitoring the amount of the styrene-acrylate copolymer present in the aqueous-based treatment fluid; and adding additional styrene-acrylate copolymer to the aqueous-based treatment fluid in response to the step of monitoring.

4. The method of claim 1 wherein the aqueous-based treatment fluid is placed in the well bore to interact with crude oil present at a specific location therein.

5. The method of claim 1 wherein the aqueous-based treatment fluid is placed into the well bore during drilling of the well bore.

6. The method of claim 1 wherein the styrene-acrylate copolymer comprises:
at least one unit selected from the group consisting of a styrene, a substituted styrene, and any derivative thereof; and
at least one unit selected from the group consisting of -acrylate, -methacrylate, -ethylacrylate, -propylacrylate, -butylacrylate, -tert-butyl-acrylate, -n-hydroxyethyl methacrylate, -potassium acrylate, -pentabromobenzyl acrylate, -methyl methacrylate, -ethyl methacrylate, -n-nitrophenyl acrylate, -methyl 2-(acyloxymethyl)acrylate, -cyclohexyl acrylate, -n-ethylhexyl acrylate, and any derivative thereof.

7. The method of claim 1 wherein the styrene-acrylate copolymer comprises a styrene-methacrylate copolymer.

8. The method of claim 1 wherein the styrene-acrylate copolymer comprises a crosslinked styrene-acrylate copolymer emulsion.

9. The method of claim 1 wherein the styrene-acrylate copolymer is derived from monomers consisting of one or more styrene monomers and one or more acrylate monomers.

10. The method of claim 1 wherein the styrene-acrylate copolymer is present in an amount of about 1% to about 10% by volume of the aqueous-based treatment fluid.

11. The method of claim 1 wherein the aqueous-based treatment fluid further comprises a surfactant.

12. A method of treating crude oil, comprising:
using a drill bit to enlarge a well bore in a subterranean formation, wherein crude oil from the subterranean formation enters the well bore, wherein the crude oil has an API gravity of about 10 or greater; and
circulating an aqueous-based drilling fluid past the drill bit, the aqueous-based drilling fluid comprising an aqueous fluid and a styrene-acrylate copolymer, wherein the aqueous-based drilling fluid has a density of about 12 pounds per gallon to about 18 pounds per gallon, wherein the styrene-acrylate copolymer interacts with the crude oil in the well bore such that the crude oil forms agglomerates in the aqueous-based drilling fluid, and wherein the crude oil is not emulsified.

13. The method of claim 12 further comprising screening the agglomerates of crude oil from the aqueous-based drilling fluid.

14. The method of claim 12 wherein the styrene-acrylate copolymer comprises:
at least one unit selected from the group consisting of a styrene, a substituted styrene, and any derivative thereof; and
at least one unit selected from the group consisting of -acrylate, -methacrylate, -ethylacrylate, -propylacrylate, -butylacrylate, -tert-butyl-acrylate, -n-hydroxyethyl methacrylate, -potassium acrylate, -pentabromobenzyl acrylate, -methyl methacrylate, -ethyl methacrylate, -n-nitrophenyl acrylate, -methyl 2-(acyloxymethyl)acrylate, -cyclohexyl acrylate, -n-ethylhexyl acrylate, and any derivative thereof.

15. The method of claim 12 wherein the styrene-acrylate copolymer comprises a styrene-methacrylate copolymer.

16. The method of claim 12 wherein the styrene-acrylate copolymer is derived from monomers consisting of one or more styrene monomers and one or more acrylate monomers.

17. The method of claim 12 wherein the styrene-acrylate copolymer is present in an amount of about 1% to about 10% by volume of the aqueous-based drilling fluid.

18. A method of treating crude oil, comprising:
using a drill bit to enlarge a well bore in a subterranean formation, wherein crude oil from the subterranean formation enters the well bore, wherein the crude oil has an API gravity of about 10 or greater;
circulating an aqueous-based drilling fluid past the drill bit, wherein the aqueous-based drilling fluid comprises an aqueous fluid and a crosslinked styrene-methacrylate copolymer emulsion in an amount sufficient to prevent emulsification of the crude oil into the aqueous-based drilling fluid, wherein the aqueous-based treatment fluid has a density of about 12 pounds per gallon to about 18 pounds per gallon; and
screening the aqueous-based drilling fluid such that the crude oil is removed from the aqueous-based drilling fluid.

19. The method of claim 18 wherein the crosslinked styrene-methacrylate copolymer emulsion is derived from monomers consisting of one or more styrene monomers and one or more methacrylate monomers.

20. The method of claim 18 wherein the crosslinked styrene-methacrylate copolymer emulsion is present in an amount of about 1% to about 10% by volume of the aqueous-based drilling fluid.

Assignees

• Halliburton Energy Services Inc

Inventors

• Livanec Philip W
• Perez Gregory P
• Deville Jay P

Classifications

• C09K8/524 Primary

  organic depositions, e.g. paraffins or asphaltenes · CPC title

• C09K8/12

  containing synthetic organic macromolecular compounds or their precursors · CPC title