Protector for threaded end of a tubular component with flexible seal

Abstract

A temporary protector is for an extremity of a tubular joint component for drilling or operating hydrocarbon wells. The protector includes a sleeve to be attached to the component extremity and to protect a free end portion and a thread of the component extremity. The sleeve has a thread to engage with the thread of the component extremity and a peripheral sealing device assembled sealingly thereon such that it is liable to be brought into contact with a surface of the component located downstream of the thread of the component extremity, to provide a seal downstream of the thread. When the protector is being installed on the tubular component, at the time that the thread of the sleeve engages with the thread of the component extremity, at least one portion of the sealing is located axially downstream of the thread of the component extremity.

Claims

1. A tubular threaded joint component for drilling or operating hydrocarbon wells, comprising: an extremity fitted with at least one internal thread and including a free end portion; a smooth body downstream of the threaded extremity; and a temporary protector screwed onto said internal thread of said extremity, said protector comprising: a sleeve configured to be attached to the extremity of the component and to protect said free end portion and the internal thread of said extremity of the component, said sleeve having a frustoconical outer surface and an external thread that is configured to engage with the internal thread of the extremity of the component and that extends axially over a distance equal to or less than the axial distance of the internal thread of the extremity of the component the frustoconical outer surface having an external diameter that is less than an internal diameter of the internal thread such that the frustoconical outer surface is not in direct contact with the extremity of the component, a peripheral sealing device assembled sealingly on a downstream end of the sleeve and configured to be brought into contact with the smooth body of said component located downstream of the internal thread of the extremity of the component, such as to provide a seal downstream of said internal thread, the frustoconical outer surface of the sleeve being located between the external thread and the peripheral sealing device, and the peripheral sealing device includes a lip that extends radially outward further than the downstream end of the sleeve, and a secondary sealing device that can be brought into contact firstly with a surface of said component, at least at the free end portion of the extremity of the component, and secondly with said sleeve such as to provide a seal upstream of said internal thread, wherein the component is dimensioned such that, when the protector is being installed on the tubular component, at the time that the external thread of the sleeve first engages with the internal thread of the extremity of the tubular joint component, the portion of the peripheral sealing device is in direct contact with the smooth body of said component located axially downstream of the internal thread of the extremity of said component.

2. The component according to claim 1, wherein the ratio of the axial distance of the internal thread of the extremity of the tubular component to the axial distance of the external thread of the sleeve of the protector is equal to or greater than 2.

3. The component according to claim 1, wherein the peripheral sealing device is rigidly connected to the sleeve.

4. The component according to claim 3, wherein the peripheral sealing device is secured to the sleeve by overmoulding.

5. The component according to claim 4, wherein the peripheral sealing device is secured to the sleeve by overmoulding performed by two-component injection.

6. The component according to claim 1, wherein the contact surface between the peripheral sealing device and the sleeve is greater than 10% of the total length of the sleeve.

7. The component according to claim 1, wherein the peripheral sealing device has at least one flap extending at least above the portion of the peripheral sealing device designed to come into contact with the surface of the component in order to at least partially protect same from the light.

8. The component according to claim 1, wherein the portion of the peripheral sealing device designed to come into contact with the surface of the tubular component is elastically flexible in at least one longitudinal axial direction of the protector.

9. The component according to claim 1, wherein the portion of the peripheral sealing device designed to come into contact with the surface of the tubular component has a bevelled contact surface and a longitudinal section that increases in the downstream-to-upstream direction.

10. The component according to claim 1, wherein the ratio of the axial distance of the internal thread of the extremity of the tubular component to the axial distance of the external thread of the sleeve of the protector is equal to or greater than 3.

11. The component according to claim 1, wherein the contact surface between the peripheral sealing device and the sleeve is greater than 20% of the total length of the sleeve.

12. A tubular threaded joint component for drilling or operating hydrocarbon wells, comprising: an extremity fitted with at least one external thread and including a free end portion; a smooth body downstream of the external threaded extremity; and a temporary protector screwed onto said external thread of said extremity, said protector comprising: a sleeve configured to be attached to the extremity of the component and to protect said free end portion and the external thread of said extremity of the component, said sleeve having an internal thread that is configured to engage with the external thread of the extremity of the component and that extends axially over a distance equal to or less than the axial distance of the external thread of the extremity of the component, a peripheral sealing device assembled sealingly on a downstream end of the sleeve and configured to be brought into contact with the smooth body of said component located downstream of the external thread of the extremity of the component, such as to provide a seal downstream of said external thread, and a secondary sealing device that can be brought into contact firstly with a surface of said component, at least at the free end portion of the extremity of the component, and secondly with said sleeve such as to provide a seal upstream of said external thread, wherein the component is dimensioned such that, when the protector is being installed on the tubular component, at the time that the internal thread of the sleeve first engages with the external thread of the extremity of the tubular joint component, the portion of the peripheral sealing device is in direct contact with the smooth body of said component located axially downstream of the external thread of the extremity of said component, and wherein the secondary sealing device includes a flange positioned at an upstream end of the sleeve, the flange extending radially inward from the sleeve, the secondary sealing device includes a partition that extends within the sleeve to close an end of the sleeve, the partition includes a radial portion at a center of the sleeve and a circular portion extending axially within the sleeve, the circular portion is connected to the radial portion at a first end and connected to the flange at a second end such that the radial portion is closer to the downstream end of the sleeve than the flange, and the radial portion of the partition is positioned within a bore of the extremity when the internal thread of the sleeve is fully engaged with the external thread of the extremity of the tubular joint component.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) Other features and advantages of the invention are set out in the detailed description below and the attached drawings, in which:

(2) FIG. 1 is a schematic longitudinal cross-sectional view of a protector according to a first embodiment,

(3) FIG. 2 is a partial schematic longitudinal cross-sectional view of a downstream extremity of a protector according to a second embodiment,

(4) FIG. 3 shows a variant embodiment of the protector in FIG. 2 including a flap for protecting the sealing device,

(5) FIG. 4 shows a second variant embodiment of the embodiment in FIG. 2,

(6) FIGS. 5 and 6 are partial schematic longitudinal cross-sectional views of a downstream extremity of a protector according to a third embodiment, and

(7) FIGS. 7a and 7b are longitudinal half cross-sectional views of a protector according to a fourth embodiment.

DETAILED DESCRIPTION

(8) The attached drawings may both complement the invention and contribute to the definition of same, as appropriate.

(9) A protector is intended to protect the threaded extremity of a tubular component of a tubular threaded joint (used for drilling or operating hydrocarbon wells or similar) against mechanical damage, contamination (chemical and material) and deterioration (corrosion) from the time same leaves the factory until it is used (the protection device potentially being assembled and disassembled several times), but also between two successive uses, by limiting (or even preventing) the storage lubricant (anticorrosion) and/or screwing lubricant from being scraped off and/or removed, specifically if the lubricant is applied permanently (semi-dry or dry lubricant, as detailed above), regardless of the dimensional variations of the tubular component (in particular the external diameter of same).

(10) There are protectors for male threaded extremities (external thread) and protectors for female threaded extremities (internal thread).

(11) In order to facilitate the assembly of the protector and in particular the installation of the sleeve on the threaded extremity, known sealing devices were usually removable, and the sealing device and the sleeve were assembled after placement of same on the components to be protected. The removable nature of the sealing device entails a risk of loss, in particular during handling of the component.

(12) Furthermore, the removable nature of the sealing device also makes it difficult to achieve an optimum seal between the sleeve and the metal surface of the component, notably on account of manufacturing imperfections on the surface of the component. It may then be necessary to deform the protector to guarantee the seal.

(13) WO2008/087302 proposes protection using half-shells and clamping. A high-quality seal is achieved, but a high number of parts are used.

(14) Application FR 2 998 639 proposes a protection device offering enhanced adaptability of the seal to the dimensional variations in the components, while remaining relatively easy to assemble. To do so, a sealing device is rolled onto the sleeve before being unrolled onto the tubular component once the sleeve has been installed. This makes installation of the protector relatively more complex and slower. Furthermore, a larger quantity of elastomer is required to make a sealing device that can be rolled up.

(15) In the remainder of the document, it is assumed that the component is intended for drilling or operating hydrocarbon wells and that it is fitted at one extremity with a sleeved tubular threaded joint from the VAM family or equivalent. However, the protector according to the present application is not limited to this type of component or to the aforementioned type of extremity. Indeed, the invention relates to all types of tubular threaded joint components for drilling or operating and all types of threaded extremities of components, in particular API and premium components, such as VAM tubular threaded joints.

(16) A tubular component has a body or main portion and two extremities: two male extremities, one-male extremity and one female extremity, or two female extremities. The component is usually made of steel or stainless steel.

(17) The body includes a bore formed by rolling. The bore of the body may have a coated inner surface, for example with an anti-corrosion coating.

(18) The roughness and diametrical tolerance of surfaces formed by rolling is much higher than the roughness and diametrical tolerance of machined surfaces. The bore of the body may extend to an axial position that is different to the axial position to which the outer surface of the body extends.

(19) A male extremity has at least one external thread and at least one free end portion, the body of the tubular component extending downstream from the male extremity.

(20) More specifically, male extremity shall be understood to mean the portion of a component that has surfaces that have been machined and/or ground to form a joint with a corresponding female portion.

(21) A female extremity has at least one internal thread and at least one free end portion, the body of the tubular component extending downstream from said female extremity.

(22) The internal and external end threads may be on one or more different threaded portions arranged on cylindrical or conical surfaces.

(23) If the or a threaded portion is conical, it may be subdivided into a perfect thread sub-portion, in which the profile is constant and free of irregularities and imperfections (such as burrs) and an imperfect or vanishing thread sub-portion, the height of which decreases progressively and the profile of which may have irregularities or imperfections.

(24) The end threads may include at least two distinct threaded portions that are axially and/or radially distant from one another, each of these portions potentially having perfect threads and vanishing threads.

(25) The free end portion of the extremity of the component usually ends with an annular surface oriented substantially transversely.

(26) The male or female extremity may also have one or more axial stop surfaces for a respectively female or male extremity of another component designed to be assembled with the component in question (to the free extremity, downstream of the thread or between two threaded portions) and one or more metal/metal sealing surfaces (to the free extremity, downstream of the thread or between two threaded portions) with the extremity in question. The protector is preferably designed to also protect these stop surfaces and/or these sealing surfaces from damage and corrosion.

(27) The embodiments disclosed below, by way of nonlimiting example, relate to a male extremity of a tubular threaded joint.

(28) A protector 1, as shown in FIG. 1, includes in general a sleeve 2 and a sealing device 4 that cooperate with one another and are designed to be placed on the (threaded) male extremity of a component.

(29) The sleeve 2 is designed to protect at least a portion of the external thread of the male extremity and the free end portion, which is also part of the male extremity. To do so, the sleeve 2 is designed to be attached to the extremity of the component and is shaped accordingly. In particular, the sleeve has a substantially tube-shaped portion.

(30) The sleeve 2 is preferably a one-piece sleeve. The sleeve may for example be made using a material injection method.

(31) Since the protection is notably mechanical, the sleeve 2 provides a certain degree of rigidity, while being able to at least partially absorb shocks. To do so, the sleeve 2 may for example be made by injecting a thermoplastic material into a suitable mould. The different families of thermoplastic materials that can advantageously be used include notably polycarbonate mixtures such as polycarbonate-polyester (PC/PBT or PC/PET) and high-density and ultra-high-density polyethylenes (PE) (PE-HD, PE-UHD).

(32) Annex I of the 2005 edition of the specification API 5CT sets out the requirements for thread protection devices, in particular the minimum resistance values against axial and angular (45) impacts for three temperatures (46, +21 and +66 C.).

(33) More specifically, for example, the product selected may be the PE-HD produced by the company DOW and sold under the name DMBA-8904-NT7, or the PE-HD produced by the company BASELL and sold under the name LUPOLEN 4261 AG UV 6005, or the PE-UHD produced by the company TICONA and sold under the name GUR 5113, or the PC-PBT produced by the company BAYER and sold under the name MAKROBLEND 57916.

(34) The sleeve 2 includes an upstream end portion 21 that is designed to be positioned at the free end portion of the tubular component and that preferably includes an inward-oriented radial projection in the form of a thick flange 22 that is designed to absorb shocks and impacts and to cover the transverse annular surface at the extremity of the free end portion of the male extremity (stop surface) in order to provide a (second) continuous local seal about the entire circumference of same at this point.

(35) In one embodiment, a partition 23 closing the sleeve on the side opposite the sealing device 4 extends from the flange 22. The partition 23 forms a stopper and is designed to penetrate the bore of the tubular component. More specifically, the partition 23 has a substantially U-shaped section with a radial portion 23a and a circular portion 23b linking the radial portion 23a to the flange 22.

(36) Alternatively, as shown in the following embodiments, the partition 23 may be substantially rectilinear and flat, i.e. radial.

(37) The flange 22 and the partition 23 form a secondary seal.

(38) In one embodiment, said protector 1 includes an annular peripheral lip. The annular peripheral lip may be formed from the sleeve or be attached thereto, notably by overmoulding of an elastic material.

(39) This secondary sealing device is in particular brought into contact with a surface of said component, at least at the free end portion of the extremity of the component. This prevents the ingress of foreign bodies such as sand, salt and water via the end portion of the extremity of the component.

(40) In the case of a protector for a male extremity, the surface of said component is in particular an inner surface. In the case of a protector for a female extremity, the surface of said component is in particular an outer surface.

(41) Downstream of the end portion 21, an inner surface of the sleeve has a thread 24 able to cooperate by complementarity of form with the thread of the extremity of the tubular component to be protected. More simply, the thread 24 is adapted to fit the thread of the extremity of the component to be protected.

(42) The thread 24 extends axially over a distance equal to or less than the axial distance of the thread of the extremity of the component. Indeed, it is desirable to be able to position and tighten the sleeve quickly. The number of turns of the thread 24 of the sleeve 2 is therefore generally low, so that it can be positioned in just a few screw turns, in particular 3 or 4.

(43) The sleeve extends downstream of the thread 24 over a distance greater than the length, measured along a longitudinal direction of the tubular component, of the thread of said component, as far as a downstream end portion 25.

(44) The downstream end portion 25 bears the sealing device 4. The sealing device 4 is designed to come into contact with an external surface of the body of the tubular component to be protected, at a portion located downstream of the thread of the extremity of said component.

(45) The sealing device 4 is thus located at a distance from the thread 24 that is greater than the length of the thread of the extremity of the component to be protected.

(46) Thus, when positioning the protector 1, when the thread 24 begins to engage with the thread of the extremity of the component, the sealing device 4 is located downstream beyond said thread of the extremity of the component.

(47) The sealing device 4 is made of an elastomer able to form a gasket and to provide a seal with the tubular component.

(48) More specifically, the sealing device 4 is made of a flexible (i.e. deformable) elastic material, i.e. one that can substantially return to its initial form. Said material may offer an elongation at break greater than 300%. To do so, it may for example be made by injection of a flexible material that is resistant to corrosion, chemical attacks, in particular industrial solvents and acids, and prolonged exposure to UV rays, without losing its mechanical properties. The different families of materials that may advantageously be used notably include neoprene elastomers such as Baypren 210 produced by LANXESS, EPDMs such as Nordel IP Hydrocarbon Rubber produced by DOW, nitriles, or any one of these materials placed in a polyolefin matrix. The sealing device 4 may be made of said material.

(49) The sealing device 4 is rigidly connected to the sleeve 2.

(50) More specifically, the sealing device 4 is made by moulding on the downstream end portion 25 of the sleeve 2 (overmoulding).

(51) The overmoulding is done by injection. If the sleeve 2 is also formed by injection, it is advantageous to form the protector using a two-component injection method.

(52) Complementarily, the sealing device 4 is formed such that it has a substantially trapezoid section with a bevelled inner surface, the thicker section being oriented towards the upstream portion of the protector.

(53) The inclusion of a bevelled surface facilitates adaptation of the sealing device to the surface irregularities of the body of the tubular component.

(54) More specifically, the bevelled surface forms an angle of 5-45 with a longitudinal axis of the protector.

(55) FIG. 2 is a partial schematic longitudinal cross-sectional view of a downstream extremity 25 of a protector 10 according to a second embodiment.

(56) The protector 10 differs from the protector 1 essentially by the shape of the sealing device 41.

(57) The sealing device 41 has a downstream portion 42 designed to come into contact with the surface of the component to be protected, having a rounded shape and substantially forming a peripheral bead.

(58) Furthermore, complementarily, the sealing device 41 extends towards the upstream portion of the protector 10, along an outer surface of the sleeve 2 over a relatively large distance. The sealing device 41 thus forms an outer coating that provides additional protection against shocks.

(59) Preferably, the contact surface between the sealing device and the sleeve is greater than 10% of the total length of the sleeve, and preferably greater than 20%.

(60) FIG. 3 shows a variant embodiment of the protector 10 in FIG. 2 fitted with a sealing device 43. The sealing device 43 differs from the sealing device 41 in that it includes a flap 44 for protecting the downstream portion 42 intended to come into contact with the surface of the component to be protected.

(61) The flap 44 makes it possible to limit the exposure of the downstream portion 42 to sunlight, and in particular to ultraviolet.

(62) FIG. 4 shows another variant embodiment of the protector 10 in FIG. 2 fitted with a sealing device 45. The sealing device 45 differs from the sealing devices 41 and 42 in that it includes a double flap 46 for protecting the downstream portion 42 intended to come into contact with the surface of the component to be protected.

(63) FIGS. 5 and 6 are partial schematic longitudinal cross-sectional views of a downstream extremity of a protector 100 according to a third embodiment.

(64) The protector 100 differs from the protector 10 essentially in that it includes a sealing device 401 that includes a portion 402 that is intended to come into contact with the surface of the tubular component and that is elastically flexible. More specifically, the portion 402 is elastically flexible in at least one longitudinal axial direction of the protector. The linking portion of narrow section linking the portion 402 to the sealing device 401 makes it possible to maintain a seal even if there is a significant dimensional variation in the surface of the component or of the protector on account of manufacturing variations or thermal variations.

(65) The flexibility of the portion 402 enables the seal to be adapted to the surface irregularities of the tubular component to be protected.

(66) Furthermore, like the protector 10, the sealing device 401 of the protector 100 is fitted with a flap 404 designed to limit the exposure of the portion 402 to ultraviolet light.

(67) FIG. 4 shows the gasket surrounding the thread of the component before the threads are meshed.

(68) A protector 200, as shown in FIGS. 7a and 7b, include a sleeve 202 and a sealing device 204 that cooperate with one another and are designed to be placed on the (threaded) female extremity of a component. The sealing device 204 includes a body 241 and a lip 242. The features shared with the preceding embodiments, in particular the materials used, are not described again. The female extremity includes an internal thread 50 prolonged by a substantially radial end surface 51. A seal seat 52 is machined on the side of the internal thread 50 opposite the end surface 51. A stop surface 53 oriented mainly radially is formed between the seal seat 52 and the bore of the body of the component.

(69) The sleeve 202 is designed to protect at least one portion of the internal thread of the female extremity and, potentially, at least one seal seat that is also part of the female extremity. To do so, the sleeve 202 is designed to be attached to the female extremity and is formed on the female extremity. In the half cross-sectional axial view, the sleeve 202 has an overall T-shaped section.

(70) The sleeve 202 includes an upstream end portion 221 designed to be positioned away from the female extremity. The upstream end portion 221 is thick and designed to absorb shocks and impacts. The upstream end portion 221 is designed to cover the transverse annular surface at the extremity of the free end portion of the female extremity, which is usually a stop surface. The upstream end portion 221 can provide a continuous local annular seal with the free end portion of the female extremity. The upstream end portion 221 is overall ring-shaped. The upstream end portion 221 has an outer surface 221a and a bore 221b.

(71) A notch 227 is formed in the outer surface 221a. The notch 227 is oriented radially inwards. The depth of the notch 227 is less than the radial thickness of the upstream end portion 221. The notch 227 is positioned in the vicinity of the free end portion of the female extremity in the tightened state (see FIG. 7b). The notch 227 delimits a portion 226 that is elastically deformable in the axial direction of the upstream end portion 221. The elastically deformable portion 226 is arranged to face the free end surface 51 of the female extremity during tightening (see FIG. 7a) and in contact with the end surface 51 of the female extremity in the tightened state (see FIG. 7b). When tightening is complete, the notch 227 is at least partially closed, providing a visual indication that tightening is complete.

(72) The sleeve 202 includes a downstream end portion 225. The upstream end portion 221 and the downstream end portion 225 form the top bar of the T. The downstream end portion 225 bears the sealing body 241. The downstream end portion 225 has a small-diameter bore next to the upstream end portion 221 and a large-diameter bore located away from the upstream end portion 221. The downstream end portion 225 has a large-diameter outer surface next to the upstream end portion 221 and a small-diameter outer surface located away from the upstream end portion 221.

(73) In this case, the sealing body 241 is overmoulded on the large-diameter bore. The sealing body 241 is overmoulded on an end radial surface of the downstream end portion 225. The sealing body 241 is also overmoulded on the small-diameter outer surface. Thus, the sealing body 241 is firmly attached to the downstream end portion 225 by at least two coaxial surfaces. The lip 242 projects radially outwards and axially against the upstream end portion 221. The lip 242 is designed to come into sealing contact with a bore of the female extremity of the component in the position shown in FIG. 7b, the downstream end portion 225 projecting inside said female extremity.

(74) The sleeve 202 includes a frustoconical outer surface 202a between the downstream end portion 225 and the upstream end portion 221. The diameter of the frustoconical outer surface 202a increases between the downstream end portion 225 and the upstream end portion 221. The frustoconical outer surface 202a is designed to pass freely into the female thread of the female extremity of the component. The external diameter of the frustoconical outer surface 202a is less than the internal diameter of the female thread. The sleeve 202 includes an external thread 224 between the frustoconical outer surface 202a and the elastically deformable portion 226. The external thread 224 is designed to engage with the female thread of the female extremity of the component in the state shown in FIG. 7b. As shown in FIG. 7a, the external thread 224 comes into contact with said female thread substantially at the same time as the lip 242 comes into contact with the bore of the female extremity. In this case, the lip 242 comes into contact with the bore of a main portion of the female extremity, i.e. a bore located downstream of the machined areas.

(75) The sleeve 202 includes an inward-oriented radial projection in the form of a flange or disk 22 forming a shutter. In one embodiment, the flange 22 extends along a radial partition 23 closing the sleeve on the side opposite the sealing device 4. The radial partition 23 forms a stopper. The radial partition 23 is positioned axially in the area of the frustoconical outer surface 202a. The flange 22 enables the bore of the upstream end portion 221 to be radially offset from the small-diameter bore of the downstream end portion 225. The diameter of the small-diameter bore of the downstream end portion 225 is less than the diameter of the bore of the upstream end portion 221. The radial partition 23 may include a small-diameter through-hole to enable pressure balancing, notably in the presence of barometric and altimetric variations.

(76) The thread 224 extends axially over a distance equal to or less than the axial length of the thread of the extremity of the component.

(77) When installing the protector 1, when the thread 224 begins to engage with the thread of the extremity of the component, the sealing device 4 is located downstream beyond said thread of the female extremity of the component.

(78) The invention is not limited to the examples described above, which are provided purely by way of example, but encompasses all of the variants that could be envisaged by the person skilled in the art within the scope of the claims below.