COATED PIPE RESISTANT TO CASING WEAR

Abstract

A steel tubular pipe, which is threaded, sleeved, or integral, includes at least one first male threaded end, an inner surface, and a metal deposition layer on the inner surface and of thickness between 0.01 mm and 0.8 mm deposited on all or part of the inner surface of the pipe.

Claims

1-17. (canceled)

18. A steel tubular pipe for drilling, exploiting hydrocarbon wells, transporting oil and gas, or geothermal or CO2 capture wells, comprising: at least one first male threaded end, an inner surface, and a metal deposition layer over the inner surface and of thickness between 0.05 mm and 0.75 mm.

19. The steel tubular pipe according to claim 18, wherein the metal deposition layer has a hardness between 35 HRC and 65 HRC.

20. The steel tubular pipe according to claim 18, wherein the metal deposition layer has a thickness between 0.05 and 0.2 mm

21. The steel tubular pipe according to claim 18, wherein the metal deposition layer over the inner surface of the pipe is in line with the male threaded end.

22. The steel tubular pipe according to claim 18, wherein the steel tubular pipe is threaded and sleeved, and the metal deposition layer extends over the inner surface of the pipe and over a first metal coating portion in line with the first male threaded end, a second metal coating portion in line with a second male end, and a third metal coating portion in line with the intermediate section of the sleeve.

23. The steel tubular pipe according to claim 22, wherein the first, second, third metal coating portions extend over a distance between 0.1 and 1 meter.

24. The steel tubular pipe according to claim 18, wherein the steel tubular pipe is threaded and sleeved and the metal deposition layer extends over all of the inner surface of the steel tubular pipe.

25. The steel tubular pipe according to claim 18, wherein the steel tubular pipe is an integral type and the metal deposition layer extends over the inner surface of the steel tubular pipe and over a first metal coating portion in line with the first male threaded end, a second metal coating portion extends from a female end towards the first male end, each portion extending over a distance between 0.1 and 1 meter.

26. The steel tubular pipe according to claim 18, wherein the steel tubular pipe is an integral type and the metal deposition layer extends over the entire inner surface of the steel tubular pipe.

27. The steel tubular pipe according to claim 18, wherein the metal deposition layer is applied by a metal spraying method, by high velocity oxy fuel, or by twin wire arc spray.

28. The steel tubular pipe according to claim 18, wherein the steel tubular pipe is an oil well pipe, or an oil well drill pipe, or an oil well string accessory.

29. The steel tubular pipe according to claim 18, wherein the metal deposition layer is chosen from chromium carbides or tungsten carbides in a cobalt matrix or a cobalt-chromium matrix or in a nickel or nickel-chromium matrix, said metal deposition layer further comprising more than 70% in weight of chromium or tungsten carbide.

30. The steel tubular pipe according to claim 18, wherein the metal deposition layer comprises in weight percentage 0.5 to 4% of boron, up to 3% of carbon, up to 3% of chromium, 2 to 25% of molybdenum or tungsten, up to 20% of vanadium.

31. The steel tubular pipe according to claim 18, wherein the metal deposition layer is arranged to have a resistance to abrasion more significant than a base steel of the tubular pipe.

32. The steel tubular pipe according to claim 18, wherein the metal deposition layer has a porosity less than 5%.

33. The steel tubular pipe according to claim 18, wherein the metal deposition layer has a porosity less than 1%.

34. The steel tubular pipe according to claim 18, wherein a wall portion of the steel tubular pipe comprising the metal deposition layer has residual stresses substantially of a same level as residual stresses of a wall portion of the steel tubular pipe not comprising the metal deposition layer.

35. A method for obtaining the steel tubular pipe according to claim 18, comprising: metal spraying of a deposit on the inner surface of the steel tubular pipe.

Description

[0027] The invention is also a method for obtaining a steel tubular pipe comprising a step of metal spraying of a deposit on the inner surface of the pipe.

[0028] FIG. 1 schematically shows a pipe in sectional view according to a first embodiment of the invention.

[0029] FIG. 2 schematically shows a pipe in sectional view according to a variation of the first embodiment of the invention.

[0030] FIG. 3 schematically shows a pipe in sectional view according to a second embodiment of the invention.

[0031] FIG. 4 schematically shows a pipe in sectional view according to a variation of the second embodiment of the invention.

[0032] The figures are not to scale, particularly in the direction of the length of the pipes, for reasons of practicality of representation.

[0033] Threaded & Sleeved Pipe

[0034] FIG. 1 shows a sectional view of a casing pipe (1) of the threaded sleeved type, provided with a first female connection (5) and with a first male connection (2). The pipe (1) comprises a first pipe (6) provided with two male connections (2, 3) and with a sleeve (4) provided with two female connections (5,7). The sleeve (4) comprises an intermediate section (14) or heel having an inner sleeved surface (15). The first pipe (6) comprises an inner surface (8) and an outer surface (9). The pipe (6) comprises on the inner surface thereof a metal coating (10) in line with the first male connection (2), extending from the male distal end (11) towards the opposite end over a coating length Lp. The metal coating (10) extends over the entire circumference of the portion of coated inner surface (8).

[0035] The coating length Lp is between 0.1 and 1 metre. Alternatively, the metal coating may extend over the entire length of the pipe.

[0036] The first pipe (1) also comprises a metal coating (10b) in line with the second male connection (3), extending over a second coating length Lb.

[0037] The sleeve (4) also comprises a metal coating (10c) at the intermediate section (14). Said coating extends over an axial length Lm.

[0038] The thickness e of the metal coating (8) is between 0.01 and 0.8 mm. Preferably, the thickness e is between 0.05 mm and 0.75 mm. Preferably, the thickness is between 0.05 and 0.2 mm. The metal coating is distinguished by the nature thereof and the thickness thereof. The thickness is chosen to prevent the inside diameter of the pipe from substantially reducing, and to maintain the transversality thereof by a string or accessories (known as “drift”).

[0039] Particularly, the metal coating is obtained by metal spraying. Metal spraying techniques make it possible not to affect the metallurgical structure of the object whereon the metal is sprayed. It is particularly important not to modify the metallurgical structure, at the connection because this is a critical element for the strength of a string of casing pipes, and also at the body of the pipe so as not to degrade the mechanical strength thereof, or again the corrosion resistance thereof. Indeed, the casing pipes are essentially pipes without welding, a weld thermally affecting the metallurgy and therefore having an influence on the mechanical resistance of the object subjected to a weld.

[0040] The metal coating is chosen from chromium carbides or tungsten carbides, particularly tungsten carbides in a Co or Co—Cr matrix, or tungsten carbides in a Ni/Ni—Cr matrix, the coating comprising, further to tungsten, 4 to 6% of carbon, 3 to 6% of chromium, 8 to 12% of cobalt.

[0041] Particularly, a tungsten carbide comprising more than 70% in weight of tungsten particles, preferably at least 85% of tungsten carbide in a cobalt-chromium matrix may be used, the coating comprising, further to tungsten, 4 to 6% of carbon, 3 to 6% of chromium, 8 to 12% of cobalt.

[0042] A tungsten carbide in a nickel-chromium matrix comprising more than 70% in weight of tungsten particles, preferably at least 85% of tungsten carbide, coating comprising, further to tungsten, 4 to 6% of carbon, 3 to 6% of chromium, 8 to 12% of cobalt.

[0043] The metal coating may comprise in weight percentage 0.5 to 4% of boron, up to 3% of carbon, up to 3% of chromium, 2 to 25% of molybdenum or tungsten, up to 20% of vanadium. In such a coating, preferably, the weight ratio of molybdenum and tungsten related to the boron is between 6 and 10.25. Such a coating has the advantage of very significantly lowering the emanations of chromium during the deposition and of being more virtuous for the environment.

[0044] Thus, the metal deposit (10) may be arranged to have a resistance to abrasion more significant than the base steel of the tubular pipe (1, 21).

[0045] Moreover, the metal deposit (10) may be arranged to have a porosity less than 5%, preferably less than 1%.

[0046] Preferably, the metal coating (8) has a hardness between 35 HRC and 65 HRC. Also preferably, the hardness is greater than 45 HRC. A high hardness allows a better resistance to wear. A hardness must be at most 65 HRC to prevent premature wear of the string of drill pipes manoeuvring inside the pipe.

[0047] The invention makes it possible to provide a resistance of the tubular component to casing wear whilst not compromising the drift of components within and whilst not compromising the performances of the connection.

[0048] The casing pipes have an inside diameter between 100 mm and 508 mm.

[0049] Preferably, the casing pipes have an inside diameter between 150 mm and 400 mm. The casing tubular component has a length between 0.01 and 15 m.

[0050] Integral Pipe

[0051] In another embodiment shown in FIG. 3, a casing pipe (21) is of the integral type, that is to say made of a single element, and is provided with a first female connection (25) and a first male connection (22). The pipe (21) comprises an inner surface (28) and an outer surface (29). The pipe (21) comprises on the inner surface thereof a metal coating (10), present in line with the first male connection (22), extending from the male distal end (23) towards the opposite female end (25) The metal coating (27) extends over the entire circumference of the portion of inner surface (28) and the metal coating (10) extends over the entire length of the pipe (21).

[0052] In a variation of this embodiment shown in FIG. 4, a casing pipe (21) is of the integral type, that is to say made of a single element, and is provided with a first female connection (25) and a first male connection (22). The pipe (21) comprises an inner surface (28) and an outer surface (29). The pipe (21) comprises over the inner surface thereof a first metal coating portion (10p) in line with the first male connection (22), extending from the male distal end (23) towards the opposite end over a coating length Lp. The metal coating (10p) extends over the entire circumference of the portion of coated inner surface (28).

[0053] The casing pipe (21) also comprises over the inner surface (28) thereof, a second metal coating portion (10b) extending from the female connection (25) to the other end over a predetermined distance Lb.

[0054] The length (Lb) of the second metal coating portion (10b) extending from the female connection (25) is between 0.1 and 1 metre, and the first metal coating portion (10p) extends from the male connection over a second length Lb between 0.1 and 1 metre. Preferably, the lengths Lb and Lp are of at least 0.2 metres.

[0055] The metal coating (10, 10p, 10b, 10m) is absent from the surface of inner threadings.

[0056] Method

[0057] The method also relates to a method for obtaining a casing pipe resistant to casing wear.

[0058] In a first step, the inner surface (8) of the pipe is prepared. Preferably, the preparation is carried out by sand blasting. Thus, the grip of the inner coating is improved. Alternatively, the preparation may be carried out by machining, in particular by turning.

[0059] In a second step, a metal coating is applied by spraying metal on the inner surface (8) of the pipe.

[0060] The metal spraying may be carried out by High Velocity Oxy Fuel (HVOF). Said method uses oxygen, a gaseous fuel as well as a filler material (powder) that will be sprayed. The spraying temperature for said technique is fairly low and also makes it possible to obtain high-density coatings and a strong bond. This method is particularly suitable for a coating applied only to a portion in line with a male connection.

[0061] Alternatively or in addition, the metal spraying may be carried out by Twin Wire Arc Spray (TWAS). The molten metal is propelled by compressed air and atomised on the substrate to form a coating. Said technique is rapid and is more indicated for applying a metal coating along the body of a casing pipe, over a large surface.

[0062] In addition, the metal spraying may be carried out by “Cold Spray”, a method for spraying powder heated and sprayed at very high velocity. This technique is complex but provides an improved performance in hardness, porosity of the coating.

[0063] This method is rapid and is compatible with an industrial implementation.

[0064] Advantageously, the material of the pipe over a wall section on which is deposited the metal coating has residual stresses substantially of the same level as the residual stresses of a wall portion of the pipe not comprising metal coating. In other words, the deposition of material does not result in the creation of additional stress in the base material or substrate.

[0065] The fine thickness of the coating makes it possible to obtain that the connection and the pipe with inner coating will be more efficient than the connection and the pipe without inner coating because the wear is significantly greater in said latter case.

[0066] Also advantageously, the coating may be applied before the machining of operational surfaces of the connection, such that a threading, a sealing surface, an abutment surface, or even after machining of the operational surfaces of the connection without the action of applying the coating before or after machining having significant influence on the mechanical properties of the connection.

[0067] This coating according to the invention is particularly effective in the case of pipes with premium connection, an assembly that is more sensitive to casing pipe wear problems.