Threaded tubular component and method for coating such a threaded tubular component

1. A method for producing a dry film comprising a matrix on a threaded tubular component for drilling or working hydrocarbon wells, the method comprising:

applying a mixture comprising a dispersion or an aqueous emulsion of a semi-crystalline thermoplastic acrylic copolymer selected from the group consisting of one or more of a styrene-acrylic, an acrylic-methacrylate, a styrene-acrylic-methacrylate, an aliphatic polyurethane-acrylic, a polyacrylate, and a vinyl acetate-ethylene-vinyl chloride terpolymer, with a solution of a potassium polysilicate having a SiO 2 /K 2 O weight ratio that is 2.5 to 3.5 onto a threaded end of the threaded tubular component by spraying said mixture in a liquid state at a mixture application temperature of from 20° C. to 40° C. onto said threaded end, thereby obtaining a threaded end coated with a film;

drying the threaded end coated with the film at a temperature that is greater than the mixture application temperature to a maximum of 80° C. for a period of at least 15 minutes; and

densifying the film at a temperature of from 80° C. to 160° C. for a period of from 30 to 60 minutes to produce said dry film comprising a matrix,

wherein

depending on whether the threaded end is male or female, a threaded zone is provided on an exterior, if male, or an interior, if female, peripheral surface of the threaded end.

2. The method according to claim 1 , further comprising:

after said densifying, hardening the film at 160° C. for a period of from 120 to 240 minutes.

3. The method according to claim 1 wherein said applying is carried out at a temperature close to a temperature of the threaded end.

4. The method according to claim 1 , wherein said mixture has a pH of 9.5 or higher.

5. The method according to claim 1 , wherein the dispersion or the aqueous emulsion of the acrylic copolymer comprises a thickener.

6. The method according to claim 1 , wherein the dispersion or the aqueous emulsion of the acrylic copolymer comprises a stabilizer.

7. The method according to claim 1 , wherein the dispersion or the aqueous emulsion of the acrylic copolymer comprises a coalescing agent.

8. The method according to claim 1 , wherein the mixture further comprises a hardener.

9. The method according to claim 1 , wherein the mixture further comprises a solid lubricant selected from the group consisting of graphite, Bi 2 S 3 , SnS 2 , a secondary amide wax, and a paraffin wax in a final proportion by weight of from 5% to 30%.

10. The method according to claim 1 , wherein the mixture further comprises a corrosion inhibitor.

11. The method according to claim 1 , wherein the mixture further comprises colloidal silica.

12. The method according to claim 1 , further comprising:

before said applying, preparing the threaded end by a surface preparation selected from the group consisting of sand blasting, a conversion treatment, an electrolytic deposit and a non-reactive treatment.

13. The method according to claim 1 , wherein a thickness of the dry film is 30 to 50 μm.

14. The method according to claim 1 , wherein said potassium polysilicate has a SiO 2 /K 2 O weight ratio of 2.5.

15. The method according to claim 1 , wherein a weight ratio in the dry film between the potassium polysilicate and the acrylic copolymer is 0.2 to 3.5.

16. The method according to claim 1 , wherein a weight ratio in the dry film between the potassium polysilicate and the acrylic copolymer is 0.2 to 0.5.

17. The method according to claim 1 , wherein the dispersion or aqueous emulsion is a dispersion or aqueous emulsion of a semi-crystalline thermoplastic acrylic copolymer selected from the group consisting of one or more of a styrene-acrylic and a styrene-acrylic-methacrylate.

18. The method according to claim 1 , wherein the dispersion or aqueous emulsion is a dispersion or aqueous emulsion of a semi-crystalline thermoplastic acrylic copolymer which is a styrene-acrylic.

19. The method according to claim 1 , wherein:

said threaded end has an optionally surface-treated carbon steel or low alloy steel contact surface optionally subjected to a surface preparation selected from the group consisting of sand blasting, a conversion treatment, an electrolytic deposit, and a non-reactive treatment, and,

said mixture is applied directly to said optionally surface-treated carbon steel or low alloy steel contact surface optionally subjected to said surface preparation.

20. A method for producing a dry film comprising a matrix on a threaded tubular component for drilling or working hydrocarbon wells, the method comprising:

applying a mixture comprising a dispersion or an aqueous emulsion of a semi-crystalline thermoplastic acrylic copolymer selected from the group consisting of one or more of a styrene-acrylic, a styrene-acrylic-methacrylate, and an aliphatic polyurethane-acrylic, with a solution of a potassium polysilicate having a SiO 2 /K 2 O weight ratio that is 2.5 to 3.5 onto a threaded end of the threaded tubular component by spraying said mixture in a liquid state at a mixture application temperature of from 20° C. to 40° C. onto said threaded end, thereby obtaining a threaded end coated with a film;

drying the threaded end coated with the film at a temperature that is greater than the mixture application temperature to a maximum of 80° C. for a period of at least 15 minutes; and

densifying the film at a temperature of from 80° C. to 160° C. for a period of from 30 to 60 minutes to produce said dry film comprising a matrix,

wherein depending on whether the threaded end is male or female, a threaded zone is provided on an exterior, if male, or an interior, if female, peripheral surface of the threaded end, and

wherein a thickness of the dry film is 30 to 50 μm.