FR3120414A1 - Segment threaded tubular element - Google Patents

Abstract

Tubular threaded element (2, 20, 30) comprising at least one thread (5, 25), a distal end (8, 28), a body (4), a segment (11, 21, 31) extending from the body (4) as far as the distal end (8, 28), the segment (11, 21) comprising said distal end (8, 28), the body (4) comprising a first surface on which is arranged at least partially the thread (5, 25), the segment (11, 21) comprising a sealing surface (10, 30) located axially between the distal end (8, 28) and the at least one thread (5,25), said body (4) being in a steel having a first elastic limit Ys1 and said segment (11, 21) being in a steel having a second elastic limit Ys2 greater than the first elastic limit Ys1. [Fig.1]

Description

Segment threaded tubular element

The invention relates to the components, threaded tubular elements and seals resulting from the assembly of two threaded tubular elements present in the tubular components used in the field of oil and gas, geothermal energy, energy, and more particularly in a method of manufacturing such an element.

Technology background

Here, the term "component" means any tube or accessory used to drill or operate a well and comprising at least one connection or connector or threaded tubular element, and intended to be assembled by threading to another component to form with this other component a tubular threaded joint. The component may for example be a tube of relatively great length (in particular about ten meters in length), or else a tubular sleeve of a few tens of centimeters in length, or even an accessory of these tubular elements. In a non-limiting way, such an accessory can be a suspension device or "hanger", a section change part or "cross-over", a safety valve, a drill rod connector or "tool joint", " sub”, and the like…

Tubular joints therefore consist of at least two threaded tubular elements. These threaded tubular elements are complementary allowing the connection of two tubular elements - one male ("Pin") and the other female ("Box") - between them. There is therefore a male threaded tubular element and a female threaded tubular element. The so-called premium or semi-premium threaded tubular elements generally comprise at least one abutment surface. A first abutment may be formed by two abutment surfaces of two threaded tubular elements, oriented substantially radially and configured so as to be in contact with each other after the screwing of the threaded tubular elements together, therefore in the assembled state or in the assembled state and during compression stresses on the tubular joint. The stops generally have negative angles with respect to the main axis of the connections. A first abutment surface may be located on the distal end of a threaded tubular member, or on the side of the thread(s) located opposite the distal end of the threaded tubular member. Intermediate abutments are also known on joints comprising at least two levels of threads, an intermediate abutment surface being between the two threads of an element.

In general, for technical and machining reasons, the different parts of the same component, whether it is the tubular element or the threaded ends, are designed using one and the same type of material ( alloy or not).

The so-called "premium" connections comprise sealing surfaces called sealing surfaces, at least one on the pin, and at least one corresponding on the box, intended to be brought into interfering contact when the pin and box connections are assembled. 'with each other, so as to form a joint having a tightness to liquids and/or gases. The sealing surfaces must maintain a seal preventing the passage of liquids and/or gases when the connections are assembled together and during the use of the tubes comprising these connections assembled in a column, for example an oil well column , that is to say that the sealing function must be maintained in the widest possible spectrum of use, including when the joint is subjected to internal pressure or to external pressure, to compressive stresses or tensile stresses, at room temperature or at high temperature, this spectrum corresponding to an operating range of the joint.

In general, the sealing surfaces are designed to work in the elastic range of the material which constitutes them so as to maintain the quality of sealing under various successive stresses.

However, to ensure a good seal, the sealing surfaces must be assembled in such a way as to create high contact pressures. It may happen, especially during assembly, when high performance is sought, that contact pressures that are too high are reached, with risks of plastification, or even risks of seizing. By seizing we mean cases where material is torn off: In the event of seizing, the sealing function is seriously compromised.

Furthermore, it is possible that the tightness of the seal is not maintained when the seal is stressed, the material supporting the sealing surfaces deforming with an amplitude of displacement of the sealing surface decreasing and canceling the interference, even with rupture of contact of the sealing surfaces.

There is a need to obtain a threaded tubular element which makes it possible to guarantee sealing even under significant stresses, while reducing the risks of seizing.

The present invention aims to solve this problem with a tubular threaded element comprising at least one thread, a distal end, a body, a segment extending from the body to the distal end, the segment comprising said distal end, the body comprising a first surface on which the thread is formed at least partially, the segment comprising a sealing surface located axially between the distal end and the at least one thread, said body being made of a steel having a first elastic limit Ys1 and said segment being in a steel having a second elastic limit Ys2 greater than the first elastic limit Ys1. Thus, the material supporting the sealing surface has an improved rigidity. The seal resulting from the assembly of such a tubular element with another tubular element has improved sealing performance under stress.

In one aspect, the distal end includes an abutment surface and the segment includes the abutment surface. This makes it possible to increase the rigidity of the element from the abutment to the level of the sealing surface and to obtain a synergy between the segment, the abutment surface and the sealing surface. The sealing surface has a reduced displacement when the seal is subjected to a compression force. The length of the segment makes it possible to distribute the stresses exerted in the material around the sealing surface. More pressure can be exerted on the thrust bearing, which induces more contact pressure on the sealing surface via the segment. The segment also makes it possible to improve sealing when the seal is subjected to a tensile force, the segment stiffening the end carrying the sealing surface. The rigidity of the end lip is increased without adding thickness on said end lip. This can avoid reducing an internal diameter of the connection at the end lip. The segment makes it possible to overcome the dimensional limitations linked to the methods of fattening and/or conification of the end of a tube.

The sealing surface of the tubular element is located axially between the thread and the distal end of the tubular element. Since the region towards the distal end is generally the region of lesser radial thickness of the threaded element, the effect of additional rigidity provided by the segment is stronger for such a location of the sealing surface.

The first elastic limit Ys1 of the body and the second elastic limit Ys2 of the segment have values noted [Ys1] [Ys2] such that:
[Ys2] ≥ 1.15 x [Ys1] and preferably [Ys2] ≥ 1.3 x [Ys1]

In another aspect, the segment has an axial length of at least 4mm.

According to one aspect, the segment can be attached to the body by additive manufacturing. This allows better control of the shape and adhesion of the segment to the body. This also makes it possible to dimensionally limit the heat-affected zone.

The segment can be produced by additive manufacturing by surfacing, by electron beam melting, by laser melting on a metal powder bed or "selective laser melting", by selective laser sintering, by direct metal deposition or "Direct Energy Deposition". , by Deposition by Binder Projection or Deposition by Laser Projection, by deposition by arc-wire additive manufacturing.

In one aspect, the segment may have an axial length of at least 4mm.

According to another aspect, the segment does not include a recess arranged for the passage of fluid or gas, or a recess arranged to house a sensor.

The segment can be in a metal chosen from alloy steels, high alloy steels, cupro-nickel alloys, titanium alloys, ceramics, glass-ceramics, or copper, cupronickel, stellite, ferrochrome.

Alternatively, the segment can be of the same metal as the metal of the body. It is indeed possible to obtain different elastic limits with steels of the same nature.

According to a variant, the segment can comprise at least a portion of the at least one thread.

According to one aspect, the tubular threaded element according to the invention may comprise a body having a first Young's modulus E1 and the segment having a second Young's modulus E2 greater than E1.

According to another variant, a tubular threaded joint can comprise at least one threaded tubular element according to the invention, in which the at least one threading comprises a first threading, the body comprises a first part of the first threading and the segment comprises a second part of the first thread, the second part of the first thread including an engaging tooth closest to the distal end.

Finally, the invention is also a method for obtaining a tubular element as described above, said method possibly comprising a step of producing the segment by a method chosen from among hardfacing methods, electron beam fusion methods, laser melting processes on a metal powder bed or “selective laser melting”, selective laser sintering processes, direct metal deposition processes or “Direct Energy Deposition”, Binder Projection Deposition or Laser Projection Deposition processes , arc-wire additive manufacturing deposition processes.

Brief description of figures

The invention will be better understood, and other aims, details, characteristics and advantages thereof will appear more clearly during the following description of several particular embodiments of the invention, given solely by way of illustration and not limitation. , with reference to the accompanying drawings.

There is a sectional view of a male end of a tubular element according to a preferred embodiment of the invention;

There is a sectional view of a female end of a tubular element according to the invention shown partially;

There is a sectional view of one end of a tubular element according to another embodiment of the invention, implemented in a joint shown partially;

There shows a preferred embodiment of the invention. There shows a partial cross-sectional view of a tubular element (2) having a main axis (X) comprising a male end or connection, comprising a first surface (3) on which a thread (5) is made, which here is an external thread , a male sealing surface (10), a distal end (8). In the example of the , the tubular element (2) comprises on the distal end (8) an abutment surface (9).

The tubular element comprises a body (4) in a first material, here a first steel having a first elastic limit Ys1. The thread (5) is made in the body (4) and is therefore made up of a first steel with a first yield strength Ys1. The thread (5) is generally obtained by machining in the body of the tubular element (2).

The connections can also comprise several threading stages, for example two threading stages. Connections can also comprise additional sealing surfaces, for example a sealing surface located on the side of the external thread (5) which is opposite to the distal end (8), or even a sealing surface located between two thread stages. The connections may have no abutment surface.

The tubular element (2) of the comprises a segment (11). The segment (11) extends over the entire thickness of the end lip of the tubular element (2). The axial location of the segment (11) is such that the segment (11) includes the sealing surface (10). In the embodiment of the , the segment (11) extends on the one hand beyond the axial position of the sealing surface (10) on the side opposite to the distal end (8), and the segment (11) extends on the other hand towards the distal end (8). In other words, the segment (11) includes the sealing surface (10) and extends to the distal end (8) that the segment (21) includes. The lip is included in the segment (11).

The segment (11) is in a steel having a second elastic limit Ys2. This elastic limit is advantageously greater than the first elastic limit Ys1. This makes it possible to make the end lip of the tubular element (2) more rigid, the end lip being the part of the tubular element (2) located between the thread (5) and the distal end (8 ). This greater rigidity is therefore also obtained at the level of the sealing surface (10). Consequently, when, in use, the tubular element is subjected to stresses such as external pressure, bending, the end lip stiffened by the segment deforms less, and the sealing surface maintains a contact more long with a corresponding sealing surface on a corresponding tubular element. The sealing performance of the connection is improved. This improved performance can be obtained without increasing the interference at the level of the sealing surfaces in contact in a joint formed by two connections, which makes it possible not to increase the risks of seizure when assembling the connections. Advantageously, the sealing surface is made of a material of greater elastic resistance and can develop a greater contact pressure at equivalent interference compared to a connection of the state of the art.

The segment (11) is an addition of material arranged so as to reinforce the structural rigidity of the end lip of a tubular element. The highest yield strength Ys2 in the segment reduces the bulk volume of added material. Thus, the end lip is more rigid for an equivalent size compared to a state-of-the-art connection.

Tests carried out have shown that a difference in elastic limit such that the second elastic limit Ys2 of the segment (11) is greater than or equal to 1.15 times the first elastic limit of the body Ys1 makes it possible to achieve a significant improvement. When the second elastic limit Ys2 of the segment (11) is greater than or equal to 1.3 times the first elastic limit of the body Ys1, the performance obtained is even better.

The segment (11) can be made of a steel having the same chemical composition as the steel of the body (4) and which has a second elastic limit Ys2 nevertheless higher than the first elastic limit Ys1 of the body, because of a distinct crystalline structure. This distinct crystal structure is achieved by heat treatment. A very satisfactory method to date is to deposit material from the segment by a known additive manufacturing method, which makes it possible to deposit drops of molten material which undergo rapid cooling during deposition, which creates a steel with elastic limit higher than that of the steel of the body (4) which is shaped by methods resulting in a longer cooling cycle.

Alternatively, the segment (11) can be made of a second steel with a chemical composition different from that of the first steel of the body (4), the second steel of the segment inherently having a higher elastic limit than the first steel of the body (4). In this case, the material of the segment (11) is also deposited by an additive manufacturing process. For example, such a steel can be chosen from a Ferro 55 alloy from the companies Boehler-Voestalpine, Deloro-Stellite-Kennametal, Carpenter, Erasteel, Hoganas. The steel can be chosen from alloy steels, high alloys, cupro-nickel alloys, titanium alloys, ceramics, glass-ceramics, or copper, cupronickel, stellite, ferrochrome, having suitable elasticity limits for use on a tubular element.

Another advantage of having a sealing surface (10) made in the segment (11) is to have a homogeneity of material between the material of the sealing surface and of the zone in which the material stresses develop. generated by the contact pressures on the sealing surface, and the material supporting this area, and to homogenize the distribution of the stresses.

The segment (11) of the must be at least 4 mm long. By length is meant the size of the profile of the segment measured axially, along the axis (X). This makes it possible to obtain a stiffening effect of the lip at the level of the sealing surface, and to cover different positions of a sealing point when the tubular element is subjected to different stresses, the sealing surfaces in contact that can move relative to each other a certain distance. Preferably, the segment (11) has an axial length at least equal to the axial length of the sealing surface and the axial distance from the sealing surface to the distal end, plus 2 mm in order to reinforce the stiffening effect.

The tubular element (20) of the is similar to that of the , with the main difference that the end of the tubular element (20) is a female end. The tubular member (20) includes a segment (21) including a sealing surface (22) and extending to the distal end (28) that the segment (21) includes.

The segment (11, 21) has an axial length of at least 4 mm. Preferably, the segment (11, 21) has an axial length at least equal to the axial length of the sealing surface and the axial distance from the sealing surface to the distal end, plus 2 mm in order to reinforce the stiffening effect. These minimum length values also apply to other embodiments.

In another embodiment, the tubular element (30) of the is shown assembled with a female connection (40) to form a seal with the male connection (31) of the tubular element (30), said female connection (40) being partially shown. The female connection (40) includes a thread (41). The tubular element (30) comprises a thread (5), a body (4), the body (4) comprises a first surface (3) on which is formed a first part (35) of the thread (5). The tubular member includes a distal end (38), said distal end including an abutment surface (39). An abutment surface is oriented substantially radially, and is arranged to come into contact with a complementary abutment surface of a connection of a corresponding tubular element with which the tubular element (30) is assembled.

The segment (31) extends from the distal end (38), includes the sealing surface (36), and extends opposite the distal end (38) to include a thread portion ( 5), or second thread part (45), said second thread part comprising a thread-engaging tooth (5). By tooth in engagement is meant a portion of thread extending substantially over one turn around the axis (X) which is in contact in the assembled state with the tooth of the corresponding female thread of the corresponding threaded end of the threaded joint. . Thus, said tooth in engagement is in a material with an elastic limit Ys2 greater than the elastic limit of the material of the body (4). Said engaged tooth is therefore more rigid. Moreover, said engaging tooth belonging to the same segment (31) as the sealing surface (36), the axial stiffness is increased on the end lip, the positioning deviations of the sealing surface under tensile stress and compression are reduced. Moreover, this tooth is often subjected to greater mechanical stresses than other teeth. There is therefore an additional effect which is the increase in the resistance of the tooth without having to increase its size. In the example shown, the segment includes an engaging tooth (45) which is the first engaging tooth of the male thread (5). The segment may include other meshing teeth.

Also, particularly when the tooth in engagement is the first tooth in engagement, is included in the segment and has a higher elastic resistance than the body, then the first tooth in engagement has better resistance to shear. The risk of "jump-out", or jumping of teeth, is reduced.

For all embodiments, the segment (11, 21, 31) does not include any pores or channels allowing gas or liquids to pass. The segment does not include a recess to house a sensor. These characteristics can apply to all the embodiments described in this application.

Also, the tubular threaded element (2; 20; 30) of the embodiments described may comprise a body (4) having a first Young's modulus E1 while the segment (11; 21; 31) has a second modulus d 'Young E2 greater than E1. Thus, the part of the tubular threaded element where the segment is located has less deformation mainly under the effect of compressive or tensile forces, reducing the variations in the axial position of the seal.

Comparative tests were carried out between a state-of-the-art connection and a connection, said connection being obtained from a state-of-the-art connection by modifying it to incorporate a segment according to the first mode of realization in accordance with the , the segment being completely located in a recess. Nominal connection diameter is 177.8 mm (7 inches), base steel is P110 alloy to API 5CT. The segment is also made of P110 steel, added by additive manufacturing, more precisely by laser powder projection. Screwing tests and then tightness tests under stress were carried out with the parts produced. A screwing test is a series of 10 assemblies/disassemblies. Leakage is tested using internal gas pressure and then external liquid pressure methods. During the screwing tests, none of the test specimens according to the invention suffered from seizing. None of the comparative examples suffered from seizing. However, all the comparative examples failed the tightness tests, while all the specimens according to the invention passed the tightness tests, the tightness tests having been carried out within the meaning of the API 5C5 standard. Thus, the invention makes it possible to increase the sealing performance under stress compared to a connection not comprising the invention, without the seizing performance being affected.

According to another aspect, the invention also relates to a method for obtaining a threaded tubular element comprising a segment. This process includes the step of choosing a tubular element with a thread, then depositing material at the end of the tubular element.

The deposition of material can be done according to a process chosen from surfacing processes, fusion processes by electron beam, laser fusion processes on a metal powder bed or "selective laser melting", selective sintering processes by laser, direct metal deposition or “Direct Energy Deposition” processes, Binder Projection Deposition or Laser Projection Deposition processes, arc-wire additive manufacturing deposition processes.

After deposition of material so as to produce the segment, the tubular element is machined at the distal end in order to produce a sealing surface, optionally an abutment surface, optionally also a portion of thread.

Claims (10)

Tubular threaded element (2; 20; 30) comprising at least one thread (5; 25; 35), a distal end (8; 28; 38), a body (4), a segment (11; 21; 31) s extending from the body (4) to the distal end (8; 28; 38), the segment (11; 21; 31) comprising said distal end (8; 28; 38), the body (4) comprising a first surface on which the thread (5; 25) is formed at least partially, the segment (11; 21; 31) comprising a sealing surface (10; 22; 36) located axially between the distal end (8; 28; 38) and the at least one thread (5; 25), said body (4) being in a steel having a first elastic limit Ys1 and said segment (11; 21; 31) being in a steel having a second yield strength Ys2 greater than the first yield strength Ys1. A tubular threaded element (2;20) according to claim 1 wherein the distal end (8;28;38) comprises an abutment surface (9;29) and the segment (11;21;31) comprises the abutment surface (9; 29; 39). Tubular threaded element (2; 20; 30) according to one of the preceding claims, in which the first elastic limit Ys1 and the second elastic limit Ys2 have values noted [Ys1] [Ys2] such that [Ys2] ≥ 1.15 x [Ys1] and preferentially [Ys2] ≥ 1.3 x [Ys1] Tubular threaded element (2; 20; 30) according to one of the preceding claims, in which the segment (11; 21; 31) has an axial length of at least 4 mm. Tubular threaded element (2; 20; 30) according to one of the preceding claims, in which the segment (11; 21; 31) is made of a metal chosen from alloy steels, high alloy steels, cupro-nickel alloys, titanium alloys, ceramics, vitroceramics, or copper, cupronickel, stellite, ferrochrome. Tubular threaded element (2; 20; 30) according to Claim 1, characterized in that the segment (11; 21; 31) is produced by additive manufacturing by surfacing, by fusion by electron beam, by laser fusion on a powder bed metal or “selective laser melting”, by selective laser sintering, by direct metal deposition or “Direct Energy Deposition”, by Deposition by Binder Projection or Deposition by Laser Projection, by deposition by arc-wire additive manufacturing. Tubular threaded element (2; 20; 30) according to the preceding claim, in which the segment (11; 21; 31) is made of the same metal as the metal of the body (4). A tubular threaded element (2; 20; 30) according to any preceding claim wherein the segment (4) comprises a portion of the at least one thread (5; 25). A tubular threaded element (2; 20; 30) according to any preceding claim wherein the body (4) has a first Young's modulus E1 and the segment (11; 21, 31) has a second Young's modulus E2 greater than E1. Tubular threaded joint (30) comprising at least one threaded tubular element according to one of claims 1 to 9, in which the at least one thread (5; 25) comprises a first thread (35), the body (4) comprises a first part (35) of the first thread (55) and the segment (11, 21; 31) comprises a second part (45) of the first thread (5), the second part (45) of the first thread (5) comprising a tooth in engagement closest to the distal end (8; 28; 38).