Compositions and methods for cleaning subterranean boreholes

Patent metadata

Field	Value
Publication number	US-9790420-B2
Application number	US-201213565811-A
Country	US
Kind code	B2
Filing date	Aug 3, 2012
Priority date	Aug 31, 2011
Publication date	Oct 17, 2017
Grant date	Oct 17, 2017

Abstract

Lipophilic fibers are effective media for cleaning non-aqueous fluids out of a subterranean wellbore. The fibers are preferably added to a drilling fluid, a spacer fluid, a chemical wash, a cement slurry or combinations thereof. Non-aqueous fluids, such as an oil-base mud or a water-in-oil emulsion mud, are attracted to the fibers as they circulate in the wellbore.

First claim

The invention claimed is:

1. A method for cleaning a borehole in a subterranean well whose surfaces are coated with a non-aqueous fluid and are initially oil wet, comprising:
(i) providing an aqueous treatment fluid comprising lipophilic fibers coated by a hydrophilic sizing to promote dispersion in the aqueous treatment fluid;
(ii) circulating the treatment fluid in the borehole; and
(iii) removing the treatment fluid from the borehole;
wherein, the non-aqueous fluid is removed from the well and the borehole surfaces are rendered water wet;
wherein the fibers contact the non-aqueous fluid, absorb 10 to 60 times their weight of the non-aqueous fluid and have a solid surface energy between 20 mN/m and 40 mN/m,
wherein the hydrophilic sizing comprises starch, xanthan polymers, guar, guar derivatives, carboxymethylcellulose, hydroxyethylcellulose, hydroxypropylcellulose, polyvinyl alcohols, or water-soluble acrylates or combinations thereof.

2. The method of claim 1 , wherein the fibers comprise polypropylene-isotactic, polypropylene-atactic, polypropylene-syndiotactic, polyester, polydimethylsiloxane, polytetrafluoroethylene, polytrifluoroethylene, polyhexylmethacrylate, polyvinylidene fluoride, poly(t-butylmethacrylate), polychlorotrifluoroethylene, polyisobutylmethacrylate, polybutylmethacrylate, polytetramethylene oxide, polytetrahydrofurane, polyisobutylene, polycarbonate, polyethylene-branched, polyethylene-linear, polyethylmethacrylate, polyvinylacetate, polyvinyl fluoride, polyethylacrylate, poly-a-methyl styrene, polyvinyltoluene, polystyrene, polyamide-12, polymethylacrylate, polymethylmethacrylate, polyvinylchloride, polyetheretherketone, polyethylene oxide, polyethyleneterephthalate, polyvinylidine chloride, or polyamide-6,6, and combinations thereof.

3. The method of claim 1 , wherein the aqueous treatment fluid comprises a drilling fluid, a spacer fluid, a chemical wash, or a cement slurry, and combinations thereof.

4. The method of claim 1 , wherein the aqueous treatment fluid further comprises a surfactant.

5. A method for cementing a subterranean well having a borehole whose surfaces are initially oil wet, comprising:
(i) providing an aqueous treatment fluid comprising lipophilic fibers coated by a hydrophilic sizing to promote dispersion in the aqueous treatment fluid;
(ii) circulating the treatment fluid in the borehole;
(iii) removing the treatment fluid from the borehole, wherein, non-aqueous fluid is removed from the well and borehole surfaces are rendered water wet;
(iv) providing a cement slurry; and
(v) placing the slurry in the well;
wherein the fibers contact the non-aqueous fluid, absorb 10 to 60 times their weight of the non-aqueous fluid and have a solid surface energy between 20 mN/m and 40 mN/m,
wherein the hydrophilic sizing comprises starch, xanthan polymers, guar, guar derivatives, carboxymethylcellulose, hydroxyethylcellulose, hydroxypropylcellulose, polyvinyl alcohols, or water-soluble acrylates or combinations thereof.

6. The method of claim 5 , wherein the fibers comprise polypropylene-isotactic, polypropylene-atactic, polypropylene-syndiotactic, polyester, polydimethylsiloxane, polytetrafluoroethylene, polytrifluoroethylene, polyhexylmethacrylate, polyvinylidene fluoride, poly(t-butylmethacrylate), polychlorotrifluoroethylene, polyisobutylmethacrylate, polybutylmethacrylate, polytetramethylene oxide, polytetrahydrofurane, polyisobutylene, polycarbonate, polyethylene-branched, polyethylene-linear, polyethylmethacrylate, polyvinylacetate, polyvinyl fluoride, polyethylacrylate, poly-a-methyl styrene, polyvinyltoluene, polystyrene, polyamide-12, polymethylacrylate, polymethylmethacrylate, polyvinylchloride, polyetheretherketone, polyethylene oxide, polyethyleneterephthalate, polyvinylidine chloride, or polyamide-6,6, and combinations thereof.

7. The method of claim 5 , wherein the aqueous treatment fluid comprises a drilling fluid, a spacer fluid, a chemical wash, or a cement slurry, and combinations thereof.

8. The method of claim 5 , wherein the aqueous treatment fluid further comprises a surfactant.

9. A method of treating a well having a borehole, the borehole drilled with oil based mud or synthetic based mud, whose surfaces are initially oil wet, the method comprising:
(i) providing an aqueous treatment fluid comprising lipophilic fibers coated by a hydrophilic sizing to promote dispersion in the aqueous treatment fluid;
(ii) circulating the treatment fluid in the borehole; and
(iii) removing the treatment fluid from the borehole;
wherein, non-aqueous fluid is removed from the well and borehole surfaces are rendered water wet;
wherein the fibers contact the non-aqueous fluid, absorb 10 to 60 times their weight of the non-aqueous fluid and have a solid surface energy between 20 mN/m and 40 mN/m,
wherein the hydrophilic sizing comprises starch, xanthan polymers, guar, guar derivatives, carboxymethylcellulose, hydroxyethylcellulose, hydroxypropylcellulose, polyvinyl alcohols, or water-soluble acrylates or combinations thereof.

10. The method of claim 9 , wherein the fibers comprise polypropylene-isotactic, polypropylene-atactic, polypropylene-syndiotactic, polyester, polydimethylsiloxane, polytetrafluoroethylene, polytrifluoroethylene, polyhexylmethacrylate, polyvinylidene fluoride, poly(t-butylmethacrylate), polychlorotrifluoroethylene, polyisobutylmethacrylate, polybutylmethacrylate, polytetramethylene oxide, polytetrahydrofurane, polyisobutylene, polycarbonate, polyethylene-branched, polyethylene-linear, polyethylmethacrylate, polyvinylacetate, polyvinyl fluoride, polyethylacrylate, poly-a-methyl styrene, polyvinyltoluene, polystyrene, polyamide-12, polymethylacrylate, polymethylmethacrylate, polyvinylchloride, polyetheretherketone, polyethylene oxide, polyethyleneterephthalate, polyvinylidine chloride, or polyamide-6,6, and combinations thereof.

11. The method of claim 9 , wherein the aqueous treatment fluid comprises a drilling fluid, a spacer fluid, a chemical wash, or a cement slurry, and combinations thereof.

Assignees

• Boulard Stephane
• Lee Jesse C
• Schlumberger Technology Corp

Inventors

• Boulard Stephane
• Lee Jesse C

Classifications

• C04B28/02

  containing hydraulic cements other than calcium sulfates · CPC title

• C09K8/524 Primary

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

• E21B33/13

  Methods or devices for cementing, for plugging holes, crevices or the like · CPC title

• C04B20/1029

  Macromolecular compounds · CPC title

• C09K8/12

  containing synthetic organic macromolecular compounds or their precursors · CPC title