PROTECTOR FOR TUBULAR THREADED ELEMENTS

Abstract

A protector is for a tubular threaded element for drilling, exploitation of hydrocarbon wells, transport of oil and gas, transport or storage of hydrogen, carbon capture or geothermy. The protector includes a main body that includes at least one exterior axial surface extending axially and facing outward in such a manner as to be able in the assembled state to face the interior surface wall of a tubular threaded element. The exterior axial surface of the main body is fitted with at least one seal adapted in the assembled state to block particles of scale.

Claims

1-11. (canceled)

12. A protector for a tubular threaded element for drilling, exploitation of hydrocarbon wells, transport of oil and gas, transport or storage of hydrogen, carbon capture or geothermy, said protector comprising: a main body, said main body including at least one exterior axial surface extending axially and facing outward in such a manner as to be able in the assembled state to face an internal wall of a tubular threaded element, wherein the exterior axial surface of said main body is fitted with at least one seal configured in the assembled state to block particles of scale.

13. The protector according to claim 12, wherein said seal is of an elastomer, a flexible bristle brush, a foam, or a plastic lip type.

14. The protector according to claim 12, wherein the exterior axial surface includes a housing configured to accommodate the seal.

15. The protector according to claim 14, wherein the exterior axial surface further includes a seal support, said seal support including said housing.

16. The protector according to claim 14, wherein said housing containing the seal includes at least one profiled section configured to retain said seal in the housing.

17. The protector according to claim 15, wherein the support is connected to the exterior axial surface by a reverse screw pitch system, a riveting system, a friction welding system, or a welding system that adds material.

18. The protector according to claim 17, wherein the reverse screw pitch system is reinforced with glue.

19. The protector according to claim 12, further comprising a thread having a thread pitch P and an abutment surface configured to be brought into contact with a corresponding abutment surface of said tubular threaded element.

20. The protector according to claim 19, wherein a minimum position of the seal relative to a axis Z is determined by the following equation: $\mathrm{Zp}2P/2$ with: P: value in mm of the thread pitch of the protector; and Zp2: value in mm of a distance along the axis Z between the abutment surface of the protector and the seal.

21. The protector according to claim 19, wherein a maximum position of the seal relative to a axis Z is determined by the following equation: $\mathrm{Zp}2+\mathrm{Zp}1\mathrm{Zf}$ with: Zf: value of a distance between the abutment surface and an end of the male or female thread of the protector along the axis Z; Zp1: value of the axial contact length of the seal at the level of the exterior axial surface along the axis Z; and Zp2: value in mm of a distance along the axis Z between the abutment surface of the protector and the seal.

22. The protector according to claim 21, wherein the maximum position of the seal relative to the axis Z is between, inclusive: $0.05\left(\mathrm{Zf}\right)\mathrm{Zp}2+\mathrm{Zp}10.3\left(\mathrm{Zf}\right)$ with: Zf: value of the distance between the abutment surface and the end of the male or female thread of the protector along the axis Z; Zp1: value of the axial contact length of the seal at the level of the exterior axial surface along the axis Z; and Zp2: value in mm of the distance along the axis Z between the abutment surface of the protector and the seal.

23. A tubular threaded element comprising: the protector acccording to claim 12.

Description

BRIEF DESCRIPTION OF THE FIGURES

[0076] The invention will be better understood and other aims, details, features and advantages thereof will become more clearly apparent in the course of the following description of particular embodiments of the invention given by way of non-limiting illustration only and with reference to the appended drawings.

[0077] FIG. 1 depicts in schematic longitudinal section a prior art protector in contact with a tubular threaded element.

[0078] FIG. 2 depicts in schematic longitudinal section a male protector in accordance with a first embodiment of the invention fitted with a seal.

[0079] FIG. 3 depicts in schematic longitudinal section a male protector in accordance with a second embodiment of the invention fitted with a seal.

[0080] FIG. 4 depicts in schematic longitudinal section a portion of a female protector in accordance with a third embodiment of the invention fitted with a seal support formed integrally with the main body including a seal.

[0081] FIG. 5 depicts in schematic longitudinal section a male protector in accordance with a fourth embodiment of the invention in the state mounted on a tubular threaded element.

[0082] FIG. 6 depicts in schematic longitudinal section a male protector including a seal in accordance with a fifth embodiment of the invention.

[0083] FIG. 7 depicts in schematic longitudinal section a portion of a male protector in accordance with a sixth embodiment of the invention including a seal support with at least one profiled section.

[0084] FIG. 8 depicts in schematic longitudinal section a portion of a male protector in accordance with a seventh embodiment of the invention including an exterior axial surface with at least one profiled section.

DETAILED DESCRIPTION OF THE FIGURES

[0085] In the remainder of the description and the claims the terms exterior and interior and the orientations axial and radial will be used to designate, in accordance with the definitions given in the description, elements of a protector or of a tubular threaded element. The longitudinal axis Z determines the axial orientation. The radial orientation is orthogonal to the longitudinal axis Z.

[0086] FIG. 1 depicts a prior art male protector 30 assembled with a male tubular threaded element 49 comprising an internal wall 48, a thread 51, a bearing surface 53 and an abutment surface 54.

[0087] To be more specific, FIG. 1 shows the paths of solid particles such as scale or corundom from inside the tubular threaded element 49, for example from the internal wall 48, and infiltrating at the level of the thread 51 by passing over the abutment surface 54 and the surface of the protector 30. The presence of said solid particles can damage the thread 51 or for example an anti-binding top layer of a coating applied to said thread 51 and is liable to lead to possible rejection of the tubular threaded element 49 when it arrives on the production or drilling site. Absence of any seal or incorrect positioning of the seal, such as a seal on the abutment surface 54 or upstream of the thread 51 to produce an external seal, leads to the same unsatisfactory result.

[0088] FIG. 2 depicts a male protector 1 in accordance with one embodiment of the invention including a male thread 12 and an abutment surface 7. Said male thread 12 is configured to be screwed onto the opposite male thread of a male tubular element 49. Said abutment surface 7 is configured to be brought into contact with the abutment surface at one end of a male tubular threaded element 49. The protector 1 also includes a main body 4 including at least one exterior radial surface 24 and at least one interior radial surface 25. The radial surfaces both extend radially and are opposite one another along a longitudinal axis Z. Said main body 4 has an exterior axial surface 21 for which in this embodiment no discontinuity is allowed. An exterior axial surface 21 begins at the abutment surface 7 and terminates at the interior radial surface 25. Said exterior axial surface does not include the thread of the protector.

[0089] By exterior axial surface is meant a cylindrical or frustoconical surface of the protector extending along a longitudinal axis Z and having a generatrix. The exterior axial surface 21 faces outward in such a manner as to be located inside a tubular threaded element and facing an internal wall of said tubular threaded element when the male or female protector is mounted on said male or female tubular threaded element.

[0090] Said exterior axial surface 21 bears a seal 10 adapted in the assembled state to block solid particles 50 such as scale. The seal 10 is mounted on the axial surface and is not part of the main body 4, that is to say is not formed integrally with the main body 4.

[0091] The seal 10 may be of elastomer, flexible bristle brush, foam or plastic lip type. These types of seal may have different additional advantages but are all at least capable of blocking solid particles such as scale or corundom.

[0092] Because of the more flexible material an elastomer type seal has improved elastic deformation and adaptation capabilities in the housing of a seal support. A foam or flexible bristle brush type seal is cheap to manufacture and very easy to install. A plastic lip type seal has the advantage of a small number of manufacturing steps.

[0093] The seal 10 being mounted on the exterior axial surface 21, the latter is configured to be brought into contact with the internal wall of a tubular threaded element during screwing of the protector onto said tubular threaded element.

[0094] The position of the seal 10 frees said seal from the problem of loosening of the protector because of movement of the tubes in the factory, during transportation and/or in the event of temperature variations. In particular this position enables said seal to remain sufficiently far away from high stress zones such as the abutment surface. In the assembled state this makes a complete seal possible without creating gaps and movement responsible for potential infiltration of solid particles into the zone of the functional surfaces of a tubular threaded element. Another advantage of the position of the seal 10 is that it makes it possible to improve the brake effect of the protector.

[0095] FIG. 3 depicts a portion of a male protector 1 in accordance with the invention. This second embodiment differs from that in FIG. 2 in that said main body 4 has an exterior axial surface 21 including a discontinuity in the form of a housing 9. The main body 4 includes a seal support 16. The seal support may be made of a different material to the main body 4 and be mounted on or formed integrally with said main body 4. However, the invention is not restricted to this embodiment and may encompass other variants in which the seal support is formed integrally with said main body 4.

[0096] In FIG. 3 the thread pitch P is the value in mm of the thread pitch of the protector 1. The thread pitch concept must be understood in the light of the standard ISO 5408:2009 which discusses the definition of threads. However, it will be noted that the male or female thread concept differs for the protectors compared to the tubular threaded elements. In fact, a male or female protector is qualified not in relation to the orientation of the thread but rather to their correspondence with the male or female tubular threaded element. For example, a protector is a male protector if it is intended to be screwed onto and to protect a male tubular threaded element. For example, the protector is a female protector if it is intended to be screwed into and to protect a female tubular threaded element.

[0097] Zf is the value of the distance along the axis Z between the abutment surface 7 and the end of the male thread 12 of the protector 1. Then, Zp1 is the value of the axial contact length of the seal 10 at the level of the exterior axial surface 21 along the axis Z. Finally, Zp2 is the value in mm of the distance along the axis Z between the abutment surface 7 of the protector 1 and the seal 10.

[0098] On the one hand, the minimum position of the seal 10 relative to the axis Z is determined by the following equation:

[00004]$\mathrm{Zp}2P/2$ [0099] with: [0100] P: value in mm of the thread pitch of the protector. [0101] Zp2: value in mm of the distance along the axis Z between the abutment surface of the protector and the seal.

[0102] This minimum position makes it possible to preserve the benefit of the brake effect if the protector is slightly loosened and has not moved back along the axis Z a distance greater than Zp2 where P/2 is a minimum safety distance equal to half the value in mm of the thread pitch P of the protector. This is a safety measure that ensures that the protector remains correctly in place on the threaded part of the tube.

[0103] On the other hand, the maximum position of the seal 10 relative to the axis Z is determined by the following equation:

[00005]$\mathrm{Zp}2+\mathrm{Zp}1\mathrm{Zf}$ [0104] with: [0105] Zf: value of the distance between the abutment surface and the end of the male or female thread of the protector along the axis Z. [0106] Zp1: value of the axial contact length of the seal at the level of the exterior axial surface along the axis Z.

[0107] Zp2: value in mm of the distance along the axis Z between the abutment surface of the protector and the seal.

[0108] Thanks to this feature, it is sure that the brake effect conferred by the seal 10 is not too high. The objective is to facilitate manual unscrewing by an operative without using an unscrewing tool in order to save time to facilitate use of the invention.

[0109] In accordance with one embodiment, the maximum position of the seal relative to the axis Z is between, inclusive:

[00006]$0.05\left(\mathrm{Zf}\right)\mathrm{Zp}2+\mathrm{Zp}10.3\left(\mathrm{Zf}\right)$ [0110] with: [0111] Zf: value of the distance between the abutment surface and the end of the male or female thread of the protector along the axis Z. [0112] Zp1: value of the axial contact length of the seal at the level of the exterior axial surface along the axis Z. [0113] Zp2: value in mm of the distance along the axis Z between the abutment surface of the protector and the seal.

[0114] This makes it possible to ensure an optimum position of the seal to obtain the best ratio between a sufficient brake effect and sufficient protection of the seal in use.

[0115] All of the equations remain valid with or without a seal support and for a male protector 1 or a female protector 2.

[0116] For simplicity, examples of empirical values of the parameters of the equations have been determined and validated for all of the equations described above. Those values are set out in table 1 below for male protectors according to the nominal outside diameter (OD) of the protector:

TABLE-US-00001 TABLE 1 OD (mm) 208.275 154.3 284.475 Zp2 (mm) 6 6 8 Zp1 (mm) 6 6 6 P (mm) 8.5 5.1 5.1 Zf (mm) 140 125 145

[0117] All the developments described for a male protector are applicable to a female protector.

[0118] FIG. 4 depicts a female protector 2 in accordance with one embodiment of the invention. The female protector 2 includes a female thread 13 configured to be screwed to the opposite female thread of a female tubular threaded element (not represented in FIG. 4) and an abutment surface 8 configured to be brought into contact with an abutment surface of a female tubular threaded element. The protector 2 also includes a main body 4 including at least one exterior radial surface 24 and at least one interior radial surface 25 extending radially and opposite one another along a longitudinal axis Z of said exterior radial surface.

[0119] Said main body 4 includes an exterior axial surface 21 which in this embodiment allows a discontinuity in the form of a housing 9 forming part of the exterior axial surface 21. There is no seal support in this figure but the female protector may equally well include a seal support 16 including said housing 9.

[0120] In FIG. 4 the thread pitch P is the value in mm of the thread pitch of the protector. Zf is the value of the distance along the axis Z between the abutment surface 8 and the end of the female thread 13 of the protector 2. Then, Zp1 corresponds to the value of the axial contact length of the seal 10 at the level of the exterior axial surface 21 along the axis |Z. Finally, Zp2 is the value in mm of the distance along the axis Z between the abutment surface 8 of the protector 2 and the seal 10.

[0121] For simplicity, examples of empirical values of the parameters of the equations have been determined and validated for all of the equations described above. Those values are set out in table 2 below for female protectors according to the nominal outside diameter (OD) of the protector:

TABLE-US-00002 TABLE 2 OD (mm) 208.275 154.3 284.475 Zp2 (mm) 4 3 3 Zp1 (mm) 6 6 6 P (mm) 8.5 5.1 5.1 Zf (mm) 99 91 136

[0122] The equations developed in FIG. 3 for a male protector are applicable to a female protector.

[0123] Generally speaking and by analogy, all of the developments established for a female protector in accordance with the invention are applicable to a male protector and vice versa.

[0124] FIG. 5 depicts a male protector 1 in accordance with one embodiment of the invention when assembled with a tubular threaded element 49. In this configuration the abutment surface of the protector 7 and the abutment surface 54 of the tubular threaded element are in contact. The threads 12 of the protector 1 and of the tubular threaded element 51 are engaged. The exterior axial surface 21 faces the internal wall 48 of the tubular threaded element 49.

[0125] In this embodiment said exterior axial surface 21 includes a discontinuity in the form of a housing 9 including a seal 10 but the invention may equally well include an exterior axial surface 21 with no housing 9 but provided with the seal 10.

[0126] In the assembled state the seal 10 is in contact with the internal wall 48 to block solid particles and in particular scale. Said seal 10 may be of elastomer, flexible bristle brush, foam or plastic lip type.

[0127] In this configuration the position of the seal 10 is clear as well as its ability to block solid particles originating from the wall 48 so that they do not damage the functional surfaces, for example the bearing surface 53 and the thread 51.

[0128] In the assembled state the interior radial surface 25 is located inside the tubular threaded element. The exterior radial surface 24 is opposite said interior surface 25 and need not be located inside the tubular threaded element.

[0129] FIG. 6 depicts a male protector 1 including an abutment surface 7, a thread 12, a main body 4 and an exterior axial surface 21. Said exterior axial surface 21 includes a seal support 16 that is not formed integrally with the main body 4 and said seal support includes a housing 9.

[0130] The seal support 16 including the housing 9 is connected to the exterior axial surface 21 by means of a reversed screw pitch system 17 or by means of a riveting system, friction welding means or welding means that add material. Each of these connecting means may optionally be reinforced with glue.

[0131] This means that the seal support can be stronger and avoids the risk of the seal support 16 becoming detached during storage and transportation and in the event of impacts caused by the production line and the loading or offloading phase. When present, the glue enables additional reinforcement of the assembly comprising the seal support 16, the housing 9 and the seal 10.

[0132] As represented in FIG. 7 the housing 9 may have a profiled section 11 at the level of the housing 9.

[0133] The exterior axial surface 21 in FIG. 6 is continuous in this embodiment but the invention encompasses the situation in which the exterior axial surface 21 may also be discontinuous.

[0134] FIG. 7 depicts an embodiment of the invention in which the exterior axial surface 21 of the male or female protector includes a local discontinuity in which a seal support 16 including a housing 9 has been mounted.

[0135] In this embodiment the material of the seal support is different from that of the main body 4 and the seal support includes a housing 9 to accommodate a seal 10. Said housing 9 has a profiled section 11 that extends along an axis Z and is configured to cover a seal partly in order to retain said seal 10 in the housing 9.

[0136] A profiled section may take various forms and may for example be a segment or a protuberance extending axially from the exterior axial surface or extending the latter. A profiled section may equally be a protuberance that extends axially from a seal support including a housing.

[0137] FIG. 8 depicts a variant of the invention in which the exterior axial surface 21 of a male or female protector including a housing 9 includes at least one profiled section 11.

[0138] Either of the profiled sections 11 extends along axis Z and projects axially from the exterior axial surface 21. The protuberant segment is configured to cover a seal 10 partly or to cover at least the base part of a seal 10 in order to retain said seal 10 in the housing 9.