Threaded tubular connection

Abstract

The invention relates to a tubular connection (1) comprising a first tubular component (2) and a second tubular component (3), each tubular component (2, 3) comprising a thread (8) and a sealing surface (9, 7, 13, 15), the threads (8, 14) having a variable thread pitch, the threads (8, 14) being intermeshed when the tubular connection (1) is in a mounted state, the sealing surfaces (7, 9, 13, 15) being in sealed contact when the tubular connection (1) is in the mounted state, the tubular connection (1) comprising a reference mark (26), the reference mark having an optimal relative position between the tubular components (2, 3), characterised in that the optimal relative position corresponds to a nominal optimal relative position to which a correction is applied, the correction being dependent on the characteristics of the one from among the first tubular component (2) and the second tubular component (3) on which the reference mark is arranged and on a target torque of the tubular connection (1).

Description

[0001] Description

[0002] Title of the invention: Threaded tubular connection

[0003] Technical field

[0004] [1]The invention relates to the field of threaded connections of tubular components intended for example for drilling, exploitation of hydrocarbon wells, transport of oil and gas, storage of fluids as well as to the field of geothermal energy or CO2 capture.

[0005] Technological background

[0006] [2]Threaded connections of tubular components, such as those used in hydrocarbon well production columns, comprise tubular components associated two by two in a sealed manner in order to transport oil, gas or any other fluid. These associated tubular components each comprise a respective threaded end. This threaded end is produced on an internal surface of said tubular component in the context of a threaded end called female (or "box", in English) or on an external surface of said tubular component in the context of a threaded end called male (or "pin", in English). These threaded ends are complementary so as to allow the two-by-two screwing of said tubular components.

[0007] [3]The tubular components of a threaded connection are assembled under defined constraints in order to meet the tightening and sealing requirements imposed by the conditions of use. Thus assembled, the tubular components form what is called a joint or a so-called as-assembled connection.

[0008] [4]In addition, in use, these threaded connections are subjected to axial tensile and / or compressive stresses, internal and / or external fluid pressures, bending or even torsion, possibly combined and of varying intensity. The sealing of these threaded connections must be ensured despite the stresses and despite the harsh operating conditions on site.

[0009] [5]Threaded connections must also be able to be screwed and unscrewed several times without degradation of their performance, in particular by seizure. After unscrewing, these components can be reused under other service conditions.

[0010] [6]Document US20070158943 describes a threaded connection having threads with variable tooth width and self-locking, i.e. with interference between flanks of the teeth of said threads. The threaded connection described in document US20070158943 further comprises metal-metal sealing surfaces. Such connections offer high torque while ensuring good sealing.

[0011] [7]As indicated in this document, it is important that the two tubular components forming the connection have a controlled relative positioning in order to ensure good cooperation of the sealing surfaces and therefore good sealing of the connection. In particular, it is important that the screwing of the two tubular components allows sufficient interference between the two sealing surfaces to ensure the sealing of the connection while avoiding too much interference which could cause seizure and / or damage the sealing surfaces.

[0012] [8]To ensure good relative positioning of the tubular components forming the connection, the connection described in document US20070158943 further comprises complementary abutment surfaces on the tubular components. The abutment of these abutment surfaces makes it possible to ensure good relative positioning between the tubular components forming the connection. However, such abutment surfaces occupy a significant radial space and therefore limit the space available for the other elements of the tubular components. Such abutment surfaces also constitute stress concentration zones which can disrupt the proper functioning of the connection. These abutment surfaces are therefore not fully satisfactory for ensuring good relative positioning of the tubular components in a connection with variable tooth width threads with interferences and comprising dedicated sealing surfaces.

[0013] [9]In order to avoid the use of stop surfaces, it is also known to use a mark, for example a visual mark, on one of the tubular components of the connection. Typically, the tubular components are screwed together until a target tightening torque is obtained, hereinafter referred to as the target torque, this target torque corresponding to a torque obtained when the threaded connection is in the assembled state. If the end of the tubular component not having the visual mark is aligned with said visual mark in the assembled state of the connection, the connection is considered to have satisfactory operating properties and is therefore validated. If, on the contrary, the end of the tubular component not having the visual mark is not aligned with said visual mark in the assembled state of the connection, then the threaded connection is considered not to have satisfactory operating properties and is therefore rejected.

[0014]

[0010] Such visual markers are arranged on one of the tubular components as a function of a nominal position of the marker. This nominal position of the marker is determined in a manner analogous to the other parameters of the connection, i.e. by means of a dimension defined in the specifications of the connection and the tubular components. More particularly, this marker is defined by a nominal optimum relative position between the tubular components as well as by nominal axial positioning tolerances on either side of this nominal optimum relative position.

[0015] [1 l]However, similarly to other parameters of the connection and tubular components, the nominal position of the reference mark is subject to manufacturing tolerances. Typically, the nominal optimum relative position as well as the nominal axial positioning tolerances are subject to manufacturing tolerances for their positioning on the tubular component.

[0016]

[0012] Furthermore, since the other structural characteristics of the tubular components are also subject to manufacturing tolerances, there is also uncertainty about the exact relative positioning of the tubular components with respect to the reference mark in the assembled state of the connection.

[0017]

[0013] Indeed, the manufacturing tolerances of the threads, interferences with the target tightening torque, the position of the sealing surfaces, etc., can lead to a situation in which the target tightening torque is reached, the end of the tubular component not including the mark is located at the right of the mark, but the sealing surfaces are not correctly positioned so as to ensure a good seal at the connection. Thus, an unsatisfactory mounted state of the connection can be validated due to the manufacturing tolerances leading to a positioning correspondence between the mark and the end of the tubular component not including said mark even though the sealing surfaces are not correctly positioned relative to each other.This poor relative positioning of the sealing surfaces can result in too little or too much interference between the sealing surfaces, causing a sealing defect or seizure, or even damage to the sealing surfaces.

[0018]

[0014] Conversely, it may happen that the target screwing torque is reached and that the free end of the tubular component not including the mark is not arranged in line with said mark even though the sealing surfaces are correctly positioned. In other words, a satisfactory mounted state may be rejected due to manufacturing tolerances leading to a lack of positioning correspondence between the mark and the end of the tubular component not including said mark.

[0015] There is therefore a need for a connection offering high torque and good sealing in a reliable manner.

[0019] Summary

[0020]

[0016] An idea underlying the invention is to provide a connection providing high torque and good sealing in a reliable manner. In particular, an idea underlying the invention is to position a relative positioning mark between two tubular components of a connection accurately and reliably. Thus, an idea underlying the invention is to take into account the structural elements of the threaded connection to determine accurate and reliable positioning of the relative positioning mark between the tubular components. An idea underlying the invention is to use the actual characteristics of the connection and the tubular components to determine the positioning of the mark.

[0021]

[0017] For this purpose, the invention provides a tubular connection comprising a first tubular component and a second tubular component, the first tubular component comprising a first thread and a first sealing surface, the first thread having a variable tooth width, the second tubular component comprising a second thread and a second sealing surface, the second thread having a variable tooth width, the first thread and the second thread being engaged in a mounted state of the tubular connection, the first sealing surface and the second sealing surface being in sealing contact in said mounted state of the tubular connection, one of the first tubular component and the second tubular component comprising a mark, said mark having an optimal relative position between the first tubular component and the second tubular component,characterized in that the optimal relative position of the reference mark is a corrected optimal relative position, said corrected optimal relative position corresponding to a nominal optimal relative position to which a correction is applied, said correction being a function of the characteristics of said one of the first tubular component and the second tubular component on which the reference mark is arranged as well as a target torque of the tubular connection.,

[0022]

[0018] A variable tooth width thread has teeth whose width, taken along an axial direction of the tubular component, increases along a direction oriented from the free end of the component towards the main body of said tubular component. This tooth width is taken at an identical height on the successive teeth, for example at the crest width of said teeth, with the exception of imperfect teeth. This variation in the width of the teeth is obtained by means of a difference in the thread pitches of the flanks of the teeth, for example the thread pitch of the engagement flanks of the teeth being greater than the thread pitch of the loading flanks of the teeth.

[0023]

[0019] Thanks to these characteristics, the mark making it possible to control the relative position between the first tubular component and the second tubular component in the assembled state of the connection is arranged on the corresponding tubular component to a satisfactory degree of precision. In particular, this positioning of the mark is determined by the actual characteristics of the tubular components and of the tubular connection and not by a theoretical position which would not take into account the manufacturing tolerances of both said mark and the other characteristics of the tubular components and of the connection.

[0024]

[0020] Thus, a mark arranged according to the above characteristics makes it possible to guarantee an adequate optimal relative positioning of the first tubular component and the second tubular component. In particular, such a mark arranged according to the above characteristics makes it possible to guarantee a satisfactory relative positioning of the first sealing surface and the second sealing surface, guaranteeing a satisfactory seal of the connection in the assembled state. Furthermore, this adequate positioning of the mark and therefore of the sealing surfaces makes it possible to ensure that there is no damage caused by excessive interference on the sealing surfaces.

[0025]

[0021] This corrected optimal relative positioning of the tubular components also makes it possible to ensure that the male tubular component is not inserted too far into the female tubular component. Such excessive insertion could cause the tubular connection to seize. Furthermore, such excessive insertion could cause the end of the male tubular component to deform radially inwards, which could prevent the passage of a control tool (from the English term "drift").

[0026]

[0022] Such a mark having a corrected optimal relative position also makes it possible to ensure satisfactory screwing of the first tubular component and the second tubular component without having to follow a screwing curve. Indeed, screwing the tubular components up to the relative positioning of the distal end of the tubular component not comprising the mark at the level of said mark is sufficient to guarantee that the tubular connection is in a satisfactory assembled state.

[0027]

[0023] A connection according to the invention advantageously makes it possible to withstand high levels of tension and compression forces in a simple and reliable manner, such a connection not requiring the presence of a stop surface to withstand high levels of tension and compression forces.

[0024] According to embodiments, such a tubular connection may comprise one or more of the following characteristics, alone or in combination.

[0028]

[0025] According to one embodiment, the correction is based on an external diameter of said one of the first tubular component and the second tubular component on which the mark is arranged.

[0029]

[0026] According to one embodiment, the correction is based on a radial thickness of said one of the first tubular component and the second tubular component on which the mark is arranged.

[0030]

[0027] According to one embodiment, the correction is based on a thread pitch of said one of the first tubular component and the second tubular component on which the mark is arranged. According to one embodiment, this thread pitch is the thread pitch of an engagement flank of the thread belonging to said one of the first tubular component and the second tubular component comprising the mark. According to one embodiment, this thread pitch is the thread pitch of a loading flank of the thread belonging to said one of the first tubular component and the second tubular component comprising the mark

[0031]

[0028] According to one embodiment, the correction is based on a target torque of the tubular connection.

[0032]

[0029] Preferably, said correction corresponds to the equation: wherein ST is a tolerance threshold, OD is an outer diameter of said one of the first tubular component and the second tubular component having the mark, Wt is a thickness of said one of the first tubular component and the second tubular component having the mark, CC is a target torque of the tubular connection, PdF is a thread pitch of the thread, preferably the largest thread pitch of the thread pitch of the loading flank and the thread pitch of the thread pitch of the engagement flank, for example the thread pitch of an engagement flank, or the thread pitch of a guide flank, belonging to said one of the first tubular component and the second tubular component having the mark.

[0033]

[0030] According to one embodiment, the first thread comprises a plurality of first teeth, the first teeth having a width, taken along a longitudinal axis of the tubular connection, increasing in a first direction along the axis of the tubular connection. [3 l]According to one embodiment, the second thread comprises a plurality of second teeth, the second teeth having a width, taken along a longitudinal axis of the tubular connection, increasing in a second direction along the axis of the connection, the first direction being opposite to the second direction.

[0034]

[0032] Preferably, the first direction is oriented from a distal end of the first tubular component toward a main body of the first tubular component. Further, the second direction is oriented from a distal end of the second tubular component toward a main body of the second tubular component.

[0035]

[0033] According to one embodiment, the corrected optimal relative position of the reference mark defines an optimal axial positioning of one distal end of the other of the first tubular component and the second tubular component. In other words, the reference mark defines, thanks to the corrected optimal relative position on one of the tubular components, where the distal end of the other tubular component must stop to obtain a satisfactory tubular connection in the assembled state.

[0036]

[0034] According to one embodiment, the tubular connection comprises a lower tolerance zone.

[0037]

[0035] Such a lower tolerance zone makes it possible to define a zone of relative positions between the tubular components in which a loss of interference between the sealing surfaces is acceptable without significant detriment to the proper functioning of the tubular connection. For example, it may be considered that a loss of interference between the first sealing surface and the second sealing surface of the order of 30% relative to the nominal interference in the assembled state of the connection, i.e. at the target torque, is acceptable. In such a case, it may be considered that a tubular connection in the assembled state having an interference of at least 70% between the first sealing surface and the second sealing surface is acceptable.This acceptable interference loss may be adapted depending on the circumstances, for example depending on the shapes of the first sealing surface and / or the second sealing surface, the presence of one or more other seals in the tubular connection, the intended conditions of use, or any other reason.

[0038]

[0036] According to one embodiment, the lower tolerance zone is determined on the one hand by the corrected optimal relative position of the reference mark and, on the other hand, by a corrected lower limit, the lower tolerance zone extending over a distance corresponding to said corrected lower limit from the corrected optimal relative position in the direction of the distal end of said one of the first tubular component and the second tubular component comprising the reference mark.

[0039]

[0037] This lower bound can be defined in many ways. For example, this lower bound can be defined arbitrarily, based on statistics of lower bounds considered acceptable. Preferably, this lower bound is determined as a function of the interference between the first sealing surface and the second sealing surface. Ideally, this lower bound is determined as a function of, on the one hand, the interference between the first sealing surface and the second sealing surface and, on the other hand, the interference between the first thread and the second thread.

[0040]

[0038] According to one embodiment, the corrected lower bound satisfies the equation: — SIXRl bound in

[0041] 7 lower = — ,„ tan 2„ (Max.\STl / ST2 \) where SI is a percentage of sealing interference, RI is an acceptable interference loss, STI is an inclination of the first sealing surface, ST2 is an inclination of the second sealing surface.

[0042]

[0039] In the context of a planar sealing surface, the inclination STI or ST2 of such a planar sealing surface corresponds to the angle formed between this planar sealing surface and the longitudinal axis of the tubular connection. In the context of a toric sealing surface, the inclination of said toric sealing surface corresponds to the angle formed by a straight line connecting the junction points of said toric sealing surface with the portions of tubular component situated axially on either side of said toric sealing surface.

[0043]

[0040] According to one embodiment, the corrected lower bound is equal to a minimum value between a first lower bound and a second lower bound, said first lower bound and second lower bound satisfying the equations: wherein SI is a sealing interference percentage, RI is an acceptable tolerance loss, STI is an inclination of the first sealing surface, ST2 is an inclination of the second sealing surface and TTdeg is an inclination of one of the first thread and the second thread, said one of the first thread and the second thread being arranged on the tubular component having the mark and Ti is a nominal interference between the first thread and the second thread at the target torque.

[0044]

[0041] Such a lower limit taking into account on the one hand the interference between the sealing surfaces and, on the other hand, the interference between the threads makes it possible to determine a very fine lower limit, guaranteeing precisely that minimal interference is ensured between the sealing surfaces when, in the assembled state of the tubular connection, the distal end of the tubular component not comprising the mark is radially in line with the mark between the corrected optimal relative position and the lower tolerance zone.

[0045]

[0042] In the context of a tubular connection whose thread teeth have a crest and / or a root inclined relative to the longitudinal axis of the connection, the inclination of the thread corresponds to the inclination of the crest and / or the root. In the context of a tubular connection whose thread teeth have a crest and a root parallel to the longitudinal axis of said tubular connection, then the inclination of the thread corresponds to the inclination of a straight line passing through the same point of the root or crest of successive teeth, teeth having singularities such as imperfect teeth not allowing a corresponding point to be defined on this straight line being ignored in the definition of this inclination.

[0046]

[0043] According to one embodiment, the tubular connection further comprises an upper tolerance zone.

[0047]

[0044] Such an upper tolerance zone makes it possible to define a zone of relative positions between the tubular components ensuring that there is no damage caused by excessive interference between the sealing surfaces. Furthermore, this upper tolerance zone makes it possible to ensure the absence of inward deformation of the tubular connection linked to excessive screwing of the tubular components together, such deformation being able to hinder the passage of a control tool ("drift" in the English term).

[0048]

[0045] According to one embodiment, the upper tolerance zone is determined on the one hand by the corrected optimal relative position of the reference mark and, on the other hand, by an upper limit, the upper tolerance zone extending over a distance corresponding to said upper limit from the corrected optimal relative position in a direction moving away from a free end of said one of the first tubular component and the second tubular component comprising the reference mark.

[0046] This upper limit can be defined in many ways. For example, this upper limit can be defined arbitrarily, on the basis of statistics of upper limits considered to be acceptable. Preferably, this upper limit is determined as a function of the interference between the first sealing surface and the second sealing surface.Ideally, this upper bound is determined based on the interference between the first sealing surface and the second sealing surface and the interference between the first thread and the second thread.

[0049]

[0047] According to one embodiment, the upper bound satisfies the equation:

[0050] IF XR2 upper bound = — „

[0051] “ tan(Max.\STl / ST2 \) in which SI is a percentage of sealing interference, R2 is an acceptable tolerance loss, STI is an inclination of the first sealing surface, ST2 is an inclination of the second sealing surface.

[0052]

[0048] According to one embodiment, the upper bound is equal to a minimum value between a first upper bound and a second upper bound, said first upper bound and second upper bound satisfying the equations:

[0053] — xR2

[0054] (v3) 7 first upper bound = - — tan( r - -, and Max.[STl / ST2]y wherein SI is a percentage of sealing interference, R2 is an acceptable tolerance loss, STI is an inclination of the first sealing surface, ST2 is an inclination of the second sealing surface and TTdeg is an inclination of one of the first thread and the second thread, said one of the first thread and the second thread being arranged on the tubular component having the mark, and Ti is a nominal interference between the first thread and the second thread at the target torque of the connection.

[0049] According to one embodiment, the first tubular component has a plurality of first sealing surfaces and the second tubular component has a plurality of second sealing surfaces.

[0055]

[0050] In the context of a plurality of sealing surfaces on each of the tubular components, the lower bound and the upper bound are defined as indicated above for each of the sealing zones of the tubular connection, such sealing zones being formed by one of the first sealing surfaces and one of the second sealing surfaces cooperating. The lower tolerance zone is then defined by the corrected optimal relative position and the minimum lower bound among the set of lower bounds. Similarly, the upper tolerance zone is then defined by the corrected optimal relative position and the minimum upper bound among the set of upper bounds.

[0056] Brief description of the figures

[0057]

[0051] 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 for illustrative and non-limiting purposes, with reference to the appended drawings.

[0058] [fig. l]Figure 1 is a sectional view of a tubular connection according to one embodiment of the invention.

[0059] [fig. 2] Figure 2 is a schematic representation of an area of ​​the tubular connection illustrated in Figure 1, said area comprising a reference mark for relative positioning of the tubular components.

[0060] [fig. 3] Figure 3 is a schematic representation of a first variant of the tubular connection illustrated in Figure 1 illustrating an area of ​​said variant, said area comprising a relative positioning mark for the tubular components.

[0061] [fig. 4] Figure 4 is a schematic representation of a second variant of the tubular connection illustrated in Figure 1 illustrating an area of ​​said variant, said area comprising a reference mark for relative positioning of the tubular components.

[0062] Description of the embodiments

[0063]

[0052] In the description, the figures and the claims, the X axis corresponds to the axis of revolution of the tubular components in the assembled state of the tubular connection, said X axis also defining an axis of the tubular connection. By convention, the “radial” orientation is directed orthogonally to the X axis and the “axial” orientation is directed parallel to the X axis.

[0053] The terms “external” and “internal” are used to define the relative position of an element, with reference to the X axis. An element close to the X axis is thus qualified as internal or radially internal as opposed to an element qualified as external or radially external located radially at the periphery.

[0064]

[0054] Oil, gas or other exploitation requires a large number of tubes associated two by two to form a column in an exploitation well. Due to the numerous constraints that these tubes undergo both during their installation and during their operation, these tubes meet standards in order to avoid any degradation and any leakage into the environment.

[0065]

[0055] Figure 1 illustrates a sectional view of a tubular connection 1 according to one embodiment of the invention. The tubular connection 1 is formed by assembling a first tubular component 2 with a second tubular component 3.

[0066]

[0056] The first tubular component 2 comprises a first main body 4 and a first connection portion 5. The first connection portion 5 is formed on an external surface of the first tubular component 2, the first tubular component 2 thus being referred to as a “male” (or “pin” in the English term). The first connection portion 5 comprises, successively from the first main body 4 to a first free end 6 of the first tubular component 2, a first external sealing surface 7, a first thread 8, a first internal sealing surface 9 and then said first free end 6 of the first tubular component 2.

[0067]

[0057] Similarly, the second tubular component 3 comprises a second main body 10 and a second connection portion 11. The second connection portion 11 is formed on an internal surface of the second tubular component 3, the second tubular component 3 thus being referred to as “female” (or “box” in the English term). The second connection portion 11 comprises, successively from the second main body 10 to a second free end 12 of said second tubular component 3, a second internal sealing surface 13, a second thread 14, a second external sealing surface 15 and then said second free end 12.

[0068]

[0058] As illustrated in Figure 1, the first thread 8 comprises a plurality of first teeth 16. The first teeth 16 have a width, taken parallel to the axis X at an identical radial tooth height on each of said first teeth 16, variable along the axis X. More particularly, said first teeth 16 have an increasing width along the axis X in a first direction oriented from the first free end 6 towards the first main body 4.

[0059] The first teeth 16 respectively have a first root 17, a first engagement flank 18, a first crest 19 and a first loading flank 20. The first engagement flanks 18 are turned towards the first free end 6. The first loading flanks 20 are turned towards the first main body 4.

[0069]

[0060] Similarly, the second thread 14 comprises a plurality of second teeth 21 with variable tooth width, said second teeth 21 having an increasing width in a second direction oriented from the second free end 12 towards the second main body 10, the first direction and the second direction thus being opposite with respect to the axis X. Similarly, the second 21 teeth have a second root 22, a second engagement flank 23 facing the second free end 12, a second crest 24 and a second loading flank 25 facing the second main body 10.

[0070]

[0061] Figure 1 illustrates the tubular connection 1 in the assembled state. This assembled state is obtained by screwing together the first tubular component 2 and the second tubular component 3. During this screwing, the first teeth 16 are engaged with the second teeth 21. More particularly, in the assembled state, the first teeth 16 and the second teeth 21 are engaged with interference. Thus, in the assembled state, the first engagement flanks 18 are in interference with the second engagement flanks 23 and the first loading flanks 20 are in interference with the second loading flanks 25.

[0071]

[0062] Similarly, in this mounted state, the first internal sealing surface 9 and the second internal sealing surface 13 are in interference contact in order to ensure good sealing of the tubular connection 1, in particular against fluids circulating inside the tubular connection 1. The first external sealing surface 7 and the second external sealing surface 15 are also in interference contact in order to ensure good sealing of the tubular connection 1, in particular against fluids outside the tubular connection 1.

[0072]

[0063] In order to ensure the correct relative positioning of the first tubular component 2 and the second tubular component 3 in the assembled state, and in particular the correct relative positioning of the sealing surfaces 7, 9, 13 and 15, a mark 26 is arranged on the first tubular component 2. More particularly and as illustrated in FIG. 2, this mark 26 is arranged on the external surface of the first main body 4.

[0073]

[0064] The reference 26 comprises a nominal optimal relative position, that is to say a theoretical position defined in the specifications intended for the manufacture of the first tubular component 2, this nominal optimal relative position being called nominal position in the remainder of the description. This nominal position defines a relative position between the first tubular component 2 and the second tubular component 3, and more particularly between the second free end 12 and the first tubular component 2, in which the different elements of the first tubular component 2 and of the second tubular component 3, in particular the sealing surfaces?, 9, 13 and 15, are positioned so as to ensure optimal operation of the tubular connection 1.

[0074]

[0065] The reference 26 further comprises a nominal lower limit and a nominal upper limit which define on either side of the nominal position zones of relative positioning between the acceptable tubular components 2 and 3. In the assembled state of the connection, the presence of the second free end 12 radially in line with these zones of relative positioning theoretically guarantees an operation of the tubular connection 1 which is not optimal but remains within acceptable operating limits. For example, these nominal lower and upper limits can define an acceptable loss of interference between the sealing surfaces 7, 9, 13 and 15 or on the contrary a maximum limit of acceptable interference with respect to optimal interference.

[0075]

[0066] However, the reliability of this mark 26 is subject to the manufacturing tolerances of the first tubular component 2 and the second tubular component 3. In particular, the mark 26 is impacted by the manufacturing tolerances of the threads 8 and 14 which influence the degree of interference between the flanks 18, 20, 23 and 25 and therefore the relative position between the first tubular component 2 and the second tubular component 3. The nominal position, the nominal upper limit and the nominal lower limit defining the mark 26 are also themselves subject to manufacturing tolerances. In addition, the sealing surfaces 7, 9, 13 and 15 are also subject to manufacturing tolerances. Thus, there is uncertainty about the reliability of the mark 26 to indicate the adequate relative positioning of the sealing surfaces 7, 9, 13 and 15.

[0076]

[0067] The influence of manufacturing tolerances on the mark 26 can lead to the validation of tubular connection 1 because the second free end 12 is arranged radially at the right of the mark 26 even though the sealing surfaces 7, 9, 13 and 15 do not cooperate in an acceptable manner. Conversely, the influence of manufacturing tolerances on the mark 26 can lead to the rejection of tubular connections 1 because the second free end

[0077] 12 is not radially in line with the mark 26 even though the sealing surfaces 7, 9,

[0078] 13 and 15 cooperate acceptably.

[0079]

[0068] In order to avoid this, the reference mark 26 according to the invention is positioned according to the actual parameters of the tubular components 2 and 3. Typically, the reference mark 26 is positioned on the first tubular component 2 according to parameters of the first tubular component 2 and of the second tubular component 3 after their manufacture, these parameters being measured, calculated or obtained by any other means. Thus, the parameters relating to one of the tubular components 2 or 3 used in the equations below are the actual parameters of said tubular component 2 or 3, for example measured after manufacture. However, the parameters relating to the tubular connection 1, such as for example the target torque CC, the percentage of interference with sealing SI or the interference Ti between the first thread 8 and the second thread 14 are the nominal values ​​of the tubular connection 1, that is to say theoretical values.These nominal values ​​are taken at the target torque for the case of interference.

[0080]

[0069] In particular, a corrected optimal relative position 27 is defined. The reference mark 26 is arranged on the first tubular component not as a function of the nominal position but as a function of this corrected optimal relative position 27, hereinafter called corrected position 27. This corrected position 27 is defined as a function of the nominal position defined in the specifications but also as a function of an external diameter OD of the first tubular component 2, a thickness Wt of the first tubular component 2 as well as the thread pitch Pdf of the first thread 8. The external diameter OD, the thickness Wt and the thread pitch Pdf are measured, calculated or obtained by any other means on the first tubular component 2 after its manufacture, they are therefore the real parameters of said first tubular component.

[0081]

[0070] The corrected position 27 is also positioned according to the target torque CC of the tubular connection 1.

[0082]

[0071] Thus, a positioning correction of the optimal relative position is calculated for the reference frame. This correction corresponds to the equation: in which ST is a tolerance threshold, OD is the outer diameter of the first tubular component 2, Wt is the thickness of the first tubular component 2, CC is the target torque of the tubular connection 2 and PdF is the thread pitch of the first thread 8, preferably the largest of a thread pitch of the loading flank and a thread pitch of the engagement flank of the first thread 8.

[0083]

[0072] The tolerance threshold ST can be determined in many ways. Preferably, this tolerance threshold ST can be determined arbitrarily, for example at a value of 96000, this value being adapted to all the connections according to the invention. A single tolerance threshold ST can also be calculated by analyzing the inclination of the threads as well as the thread pitches, in particular the "wedge ratio", i.e. a difference between the thread pitch of the engagement flanks and the thread pitches of the loading flanks.

[0084]

[0073] This equation makes it possible to obtain a displacement distance from the nominal position. Thus, the corrected position 27, and therefore the arrangement position of the mark 26 on the first tubular component 2, is obtained by applying to the nominal position a displacement of a value corresponding to the correction obtained.

[0085]

[0074] This correction makes it possible to position reference 26 precisely and reliably. In particular, the corrected position 27 takes into account the manufacturing tolerances of the first tubular component 2 and of the tubular connection 1 so that this corrected position 27 corresponds to a relative positioning of the second free end 12 with respect to the reference 26 in which the sealing surfaces 7, 9, 13 and 15 are actually correctly positioned to ensure the sealing of the tubular connection 1.

[0086]

[0075] Furthermore, the reference mark 26 arranged from the corrected position 27 comprises a corrected lower limit 28 and a corrected upper limit 29 which can be determined in numerous ways.

[0087]

[0076] For example, the corrected lower limit 28 and / or the corrected upper limit 29 may be determined by, respectively, a nominal lower limit and / or a nominal upper limit. The reference mark 26 in this case comprises lower and upper tolerance zones determined by the corrected position 27 and these nominal limits.

[0088]

[0077] Alternatively, the corrected lower bound 28 and / or the corrected upper bound 29 may be determined based on acceptable bound statistics.

[0089]

[0078] Preferably, analogously to the corrected position 27, the corrected lower limit 28 and / or the corrected upper limit 29 are also determined from the actual structural parameters of the tubular connection 1 in order to further improve the reliability and accuracy of the reference mark 26.

[0090]

[0079] Thus, the corrected lower limit 28 is advantageously determined as a function of the desired minimum interference between the sealing surfaces 7, 9, 13 and 15. Similarly, the corrected upper limit 29 is advantageously corrected as a function of the desired interference between the sealing surfaces 7, 9, 13 and 15.

[0091]

[0080] Ideally, the lower limit is determined as a function of the desired minimum interference between the sealing surfaces 7, 9, 13 and 15 but also as a function of the interference between the threads 8 and 14. Similarly, ideally, the corrected upper limit 29 is determined as a function of the desired interference between the sealing surfaces 7, 9, 13 and 15 but also as a function of the interference between the threads 8 and 14.

[0092]

[0081] In the context of a connection comprising a plurality of seals as illustrated in FIG. 1, a corrected lower bound is determined for each of the seals so as to obtain a plurality of corrected lower bounds. The corrected lower bound used to define the reference mark 26 is then the smallest corrected lower bound among this plurality of corrected lower bounds. Similarly, a corrected upper bound is calculated for each of the seals and the corrected upper bound used to define the reference mark 26 is the smallest corrected upper bound among the plurality of corrected upper bounds obtained as a function of the plurality of seals.

[0093]

[0082] Thus, in the context of the tubular connection illustrated in FIG. 1 comprising an internal seal formed jointly by the first internal sealing surface 9 and the second internal sealing surface 13 and an external seal formed jointly by the first external sealing surface 7 and the second external sealing surface 15, corrected limits are determined for the internal seal and corrected limits are determined for the external seal. The corrected lower limit 28 of the reference 26 is then the smallest corrected lower limit among those determined for the internal seal and for the external seal. Similarly, the corrected upper limit 29 of the reference 26 is then the smallest corrected upper limit among those determined for the internal seal and for the external seal.

[0094]

[0083] I1 is described below the positioning of the corrected lower bound and the corrected upper bound in a generic manner for a sealing zone, the description below being applicable for each of the different seals.

[0095]

[0084] According to an embodiment taking into account the real interference between the sealing surfaces, the corrected lower limit 28 satisfies the equation: — if XRI limit in

[0096] 1 lower = — „ tan(Max.\STl / ST2 \) in which SI is a percentage of sealing interference, RI is an acceptable interference loss between sealing surfaces, STI is an inclination of the first sealing surface, ST2 is an inclination of the second sealing surface.

[0097]

[0085] Such a corrected lower bound 28 thus takes into account the impact of the desired actual interference between the sealing surfaces to validate or reject a tubular connection 1.

[0086] In the context of a planar sealing surface, the inclination of such a planar sealing surface corresponds to the angle formed between this planar sealing surface and the axis X of the tubular connection 1.

[0098]

[0087] In the context of a toric sealing surface, the inclination of said toric sealing surface corresponds to the angle formed by a straight line connecting the junction points of said toric sealing surface with the portions of tubular component located axially on either side of said toric sealing surface.

[0099]

[0088] An acceptable interference loss between the sealing surfaces may be determined based on the shape of the sealing surfaces, the desired performance of the tubular connection 1 or any other reason. This interference loss between the sealing surfaces is for example 30%, i.e. a minimum interference of 70% is ensured by the corrected lower bound.

[0100]

[0089] Similarly, the upper bound corresponds to the equation:

[0101] IF

[0102] XR2 upper bound = — ,„ 2 "

[0103] “ tan(Max.\STl / ST2 \) in which SI is the percentage of sealing interference, R2 is the maximum acceptable interference between the sealing surfaces, STI is the inclination of the first sealing surface, ST2 is the inclination of the second sealing surface.

[0104]

[0090] A maximum acceptable interference between the sealing surfaces may be determined based on the shape of the sealing surfaces, the performance of the desired tubular connection or any other reason. This maximum acceptable interference between the sealing surfaces is for example 40%.

[0105]

[0091] Such a corrected upper bound thus takes into account the impact of the desired actual interference between the sealing surfaces to validate or reject a tubular connection 1.

[0106]

[0092] According to a preferred embodiment taking into account the real interference between the sealing surfaces but also the interference between the threads, the corrected lower limit is equal to a minimum value between a first corrected lower limit and a second corrected lower limit, said first corrected lower limit and second corrected lower limit satisfying the equations: then second lower bound = 0, and first lower bound xtan(TT t ; ea ) if Ti — > 0 , then in which SI is the percentage of sealing interference, RI is the acceptable tolerance loss, STI is the inclination of the first sealing surface, ST2 is the inclination of the second sealing surface and TTdeg is an inclination of the thread corresponding to the tubular component on which the mark 26 is arranged and Ti is a nominal interference between the first thread and the second thread at the target torque of the connection.

[0107]

[0093] Such a corrected lower bound taking into account on the one hand the interference of the sealing surfaces and, on the other hand, the interference between the threads, makes it possible to determine a very finely corrected lower bound, precisely guaranteeing that minimal interference is ensured in the assembled state of the tubular connection 1.

[0108]

[0094] Similarly, the corrected upper bound is equal to a minimum value between a first corrected upper bound and a second corrected upper bound, said first corrected upper bound and second corrected upper bound satisfying the equations: in which SI is the percentage of sealing interference, R2 is the acceptable tolerance loss between the sealing surfaces, STI is the inclination of the first sealing surface, ST2 is the inclination of the second sealing surface and TTdeg is the inclination of the thread corresponding to the tubular component on which the mark 26 is arranged, and Ti is a nominal interference between the first thread and the second thread at the target connection torque.

[0109]

[0095] In this preferred embodiment, both the impact of the actual desired interference between the sealing surfaces and the impact of the actual interference between the threads are taken into account to validate or reject a tubular connection reliably and accurately.

[0096] Figures 1 and 2 illustrate a tubular connection 1 in which the mark 26 is arranged on the external surface of the main body 4 of a first tubular component 2 of the male type and makes it possible to validate said tubular connection depending on the relative position of the second free end 12 with respect to the mark 26. However, the invention applies analogously in the context of tubular connection having other configurations.

[0110]

[0097] Figures 3 and 4 illustrate such examples of other configurations, the above description with respect to reference 26, corrected position 27, corrected lower limit 28 and corrected upper limit 29 applying analogously in such other configurations of the tubular connection 1. In these Figures 3 and 4, elements that are identical or fulfill the same function as elements described above with respect to Figures 1 and 2 bear the same reference. In the description below of Figures 3 and 4, only elements different from those already described above with respect to Figures 1 and 2 are detailed, elements not described with respect to Figures 3 and 4 being identical to those already described with respect to Figures 1 and 2.

[0111]

[0098] Figure 3 illustrates the case of a tubular connection 1 called “flush”, that is to say one whose external diameter is less than 101% of the external diameters of the tubular components 2 and 3 which form it. In this tubular connection 1, the mark 26 is arranged on the external surface of the first connection portion 5 of the first tubular component 1. More particularly, the mark 26 is arranged between the first main body 4 and the first external sealing surface (not illustrated.

[0112]

[0099] Figure 4 illustrates the case of a tubular connection 1 in which the mark 26 is arranged on the internal surface of the second tubular component 3, that is to say on the tubular component 3 of the female type. This mark 26 then makes it possible to validate or reject the tubular connection 1 depending on the relative position between the mark 26 and the first free end 6. Furthermore, the mark 26 is then arranged on the internal surface of the second connection portion 11 axially between the second main body 10 and the second internal sealing surface 13.

[0113]

[0100] Only the elements relevant to the invention have been described with reference to Figures 1 to 4, the tubular connection being able to include other characteristics not described above. Thus, for example, the tubular connection illustrated in Figure 1 includes an external groove for collecting the grease that can be applied to the tubular components, the first tubular component may include a chamfer connecting a face of the free end of the first tubular component and an internal surface of said first tubular component, etc.

[0101] The invention is described above with reference to Figures 1 to 4 in the context of preferred embodiments. However, the invention also covers embodiments not illustrated.

[0114]

[0102] For example, the invention is applicable in the context of an integral or coupled-sleeved type connection. In an integral connection, very long tubular components comprise at one end a male type connection element and at the other end a female type connection element, these very long components being assembled two by two directly. In a coupled-sleeved type connection, very long tubular components comprise at each end a male type connection element, shorter tubular components called couplers comprising at each end female type connection elements, two very long tubular components being associated by means of a coupler.

[0115]

[0103] The connections may be of the flush or semi-flush type. A flush connection is a connection whose external diameter is at most equal to 101% of the external diameter of the body of the tubular component attached to the connection. A semi-flush connection is a connection whose external diameter is at most equal to 110% of the external diameter of the body of the tubular component attached to the connection.

[0116]

[0104] Similarly, the invention is described above in the context of single threads, the invention being applicable in the context of threads comprising several threaded zones, for example on several levels.

[0117]

[0105] The invention is also applicable in the context of a tubular connection comprising one or more sealing zones, located for example on either side of the threads and / or comprising a central sealing zone.

[0118]

[0106] Similarly, the roots and crests of the teeth of the threads may be parallel to the axis of the tubular connection or parallel to the inclination of the threads. Such teeth may have a dovetail profile, also called a "dovetail", or a trapezoidal profile.

[0119]

[0107] The mark can be made in different ways. Thus, such a mark can be made for example by knurling, by machining a groove forming the visual mark, by laser marking, painting, by punching the mark or other.

[0120]

[0108] In the case of a tubular connection comprising a plurality of first sealing surfaces and a plurality of corresponding second sealing surfaces forming two by two distinct sealing zones, then the corrected lower limit, and the corrected upper limit, is the minimum value between the lower limits, respectively limit between the upper limits, calculated for each of the sealing zones.

[0121]

[0109] Although the invention has been described in connection with several particular embodiments, it is quite obvious that it is in no way limited thereto and that it includes all the technical equivalents of the means described as well as their combinations if these fall within the scope of the invention.

[0122]

[0110] The use of the verb "comprise", "comprise" or "include" and its conjugated forms does not exclude the presence of other elements or other steps than those set out in a claim.

[0111] In the claims, any reference sign in parentheses cannot be interpreted as a limitation of the claim.

Claims

Claims

1. Tubular connection (1) comprising a first tubular component (2) and a second tubular component (3), the first tubular component (2) comprising a first thread (8) and a first sealing surface (9, 7), the first thread (8) having a variable tooth width, the second tubular component (3) comprising a second thread (14) and a second sealing surface (13, 15), the second thread (14) having a variable tooth width, the first thread (8) and the second thread (14) being engaged in a mounted state of the tubular connection (1), the first sealing surface (7, 9) and the second sealing surface (13, 15) being in sealing contact in said mounted state of the tubular connection (1), one of the first tubular component (2) and the second tubular component (3) comprising a mark (26),said mark having an optimal relative position between the first tubular component (2) and the second tubular component (3), characterized in that the optimal relative position of the mark (26) is a corrected optimal relative position (27), said corrected optimal relative position (27) corresponding to a nominal optimal relative position to which a correction is applied, said correction being a function of the characteristics of said one of the first tubular component (2) and the second tubular component (3) on which the mark is arranged as well as a target torque of the tubular connection (1).,

2. Tubular connection (1) according to claim 1, wherein the correction satisfies the equation: in which ST is a tolerance threshold, OD is an external diameter of said one of the first tubular component (2) and the second tubular component (3) comprising the mark (26), Wt is a thickness of said one of the first tubular component (2) and the second tubular component (3) comprising the mark (26), CC is a target torque of the tubular connection (1), PdF is a thread pitch of the thread belonging to said one of the first tubular component (2) and the second tubular component (3) comprising the mark (26).

3. Tubular connection (1) according to claim 1 or 2, further comprising a lower tolerance zone.

4. Tubular connection (1) according to claim 3, wherein said lower tolerance zone is determined on the one hand by the corrected optimal relative position (27) of the mark (26) and, on the other hand, by a corrected lower limit (28), the lower tolerance zone extending over a distance corresponding to said corrected lower limit (28) from the corrected optimal relative position (27) towards a free end (6, 12) of one of the first tubular component (2) and the second tubular component (3) comprising the mark (26).

5. Tubular connection (1) according to claim 4, in which the corrected lower terminal (28) corresponds to terminal inf J exterior in which SI is a percentage of interference to sealing, RI is an acceptable interference loss, STI is an inclination of the first sealing surface (7, 9), ST2 is an inclination of the second sealing surface (13, 15).

6. Tubular connection (1) according to claim 5, wherein the corrected lower bound is equal to a minimum value between a first lower bound and a second lower bound, said first lower bound and second lower bound satisfying the equations: then second lower bound = 0, and if where SI is a percentage of sealing interference, RI is an acceptable tolerance loss, STI is an inclination of the first sealing surface, ST2 is an inclination of the second sealing surface and TTdeg is an inclination of one of the first thread (8) and the second thread (14), said one of the first thread (8) and the second thread (14) being arranged on the tubular component having the mark (26) and Ti is a nominal interference between the first thread and the second thread.

7. Tubular connection (1) according to one of the preceding claims, further comprising an upper tolerance zone.

8. Tubular connection (1) according to claim 7, wherein said upper tolerance zone is determined on the one hand by the corrected optimal relative position (27) of the mark (26) and, on the other hand, by a corrected upper limit (29), the upper tolerance zone extending over a distance corresponding to said corrected upper limit (29) from the corrected optimal relative position (27) in a direction moving away from a free end (6, 12) of one of the first tubular component (2) and the second tubular component (3) comprising the mark (26).

9. Tubular connection according to claim 8, in which the upper terminal satisfies the equation: x R2 upper terminal = - - Ftan(Max. [ST1 / ST2]) where SI is a percentage of sealing interference, R2 is an acceptable tolerance loss, STI is an inclination of the first sealing surface (7, 9), ST2 is an inclination of the second sealing surface (13, 15).

10. Tubular connection (1) according to claim 9, wherein the corrected upper bound (29) is equal to a minimum value between a first upper bound and a second upper bound, said first upper bound and second upper bound satisfying the equations: — xR2 (v3) 7 first upper bound = - — r - - tan(Max.\STl / ST2 \) then second upper bound = 0, and in which SI is a percentage of interference at sealing, R2 is an acceptable tolerance loss, STI is an inclination of the first sealing surface (7, 9), ST2 is an inclination of the second sealing surface (13, 15) and TTdeg is an inclination of one of the first thread (8) and the second thread (14), said one of the first thread (8) and the second thread (14) being arranged on the tubular component having the mark (26) and Ti is a nominal interference between the first thread and the second thread.

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