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

technical field

[0001] The invention relates to the field of threaded connections of tubular components intended for example for drilling, the operation of hydrocarbon wells, the transport of oil and gas, the storage of fluids as well as the field of geothermal energy or CO2 capture. Technological background

[0002] Threaded connections of tubular components, such as those used in hydrocarbon well casings, consist of tubular components joined in pairs to ensure a leak-proof connection for transporting oil, gas, or other fluids. Each of these joined tubular components has a threaded end. This threaded end is located on an internal surface of the tubular component in the case of a female threaded end (or "box") or on an external surface of the tubular component in the case of a male threaded end (or "pin"). These threaded ends are complementary, allowing the tubular components to be screwed together in pairs.

[0003] The tubular components of a threaded connection are assembled under defined constraints to meet the tightening and sealing requirements imposed by the operating conditions. Once assembled, the tubular components form what is known as a joint or a connection in its assembled state.

[0004] Furthermore, in use, these threaded connections are subjected to axial tensile and / or compressive stresses, internal and / or external fluid pressures, bending, and torsion, possibly combined, and of varying intensity. The sealing of these threaded connections must be ensured despite these stresses and despite harsh operating conditions on site.

[0005] Threaded connections must also be able to be screwed and unscrewed multiple times without degradation of their performance, particularly due to seizing. After unscrewing, these components can be reused under other service conditions.

[0006] US20070158943 describes a threaded connection with variable-width, self-locking threads, meaning threads with interference between the flanks of the teeth. The threaded connection described in US20070158943 also features metal-to-metal sealing surfaces. Such connections offer high torque while ensuring a good seal.

[0007] As indicated in this document, it is important that the two tubular components forming the connection have a controlled relative positioning to ensure proper interaction of the sealing surfaces and therefore a proper seal. In particular, it is important that the screwing of the two tubular components allows sufficient interference between the two sealing surfaces to ensure a watertight connection while avoiding excessive interference that could cause seizing and / or damage to the sealing surfaces.

[0008] To ensure proper relative positioning of the tubular components forming the connection, the connection described in document US20070158943 also includes additional buttressing surfaces on the tubular components. The buttressing of these surfaces ensures proper relative positioning between the tubular components forming the connection. However, such buttressing surfaces occupy a significant radial space and therefore limit the space available for the other elements of the tubular components. Furthermore, such buttressing surfaces constitute stress concentration zones that can disrupt the proper functioning of the connection. Therefore, these buttressing surfaces are not entirely satisfactory for ensuring proper relative positioning of the tubular components in a variable-width threaded connection with interference and dedicated sealing surfaces.US documents 2010 / 171305, GB 1173471 and WO 01 / 29476 also describe threaded connections.

[0009] To avoid the use of thrust surfaces, it is also common practice to use a marker, for example a visual marker, on one of the tubular components of the connection. Typically, the tubular components are screwed together until a target tightening torque, hereinafter referred to as the target torque, is achieved. This target torque corresponds to the torque obtained when the threaded connection is in the assembled state. If the end of the tubular component without the visual marker is aligned with the said visual marker in the assembled state of the connection, the connection is considered to have satisfactory operating properties and is therefore accepted. Conversely, if the end of the tubular component without the visual marker is not aligned with the said visual marker in the assembled state of the connection, then the threaded connection is considered to have unsatisfactory operating properties and is therefore rejected.

[0010] Such visual reference points are arranged on one of the tubular components according to a nominal reference point position. This nominal reference point position is determined analogously to the other connection parameters, i.e., by means of a dimension defined in the specifications for the connection and the tubular components. More specifically, this reference point is defined by a nominal optimal relative position between the tubular components and by nominal axial positioning tolerances on either side of this nominal optimal relative position.

[0011] However, similarly to other connection and tubular component parameters, the nominal position of the reference mark is subject to manufacturing tolerances. Typically, the nominal optimal relative position, as well as the nominal axial positioning tolerances, are subject to manufacturing tolerances for their positioning on the tubular component.

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

[0013] Indeed, manufacturing tolerances for threads, interference with the target tightening torque, the position of sealing surfaces, etc., can lead to a situation where the target tightening torque is reached, the end of the tubular component without the mark is aligned with the mark, but the sealing surfaces are not correctly positioned to ensure a proper seal at the connection. Thus, an unsatisfactory assembled connection condition can be accepted due to manufacturing tolerances resulting in a positioning match between the mark and the end of the tubular component without the 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 respectively a sealing defect or seizing, or even degradation of the sealing surfaces.

[0014] Conversely, it can happen that the target tightening torque is reached, but the free end of the tubular component without the mark is not aligned with that mark, even though the sealing surfaces are correctly positioned. In other words, a satisfactory assembly condition can be rejected due to manufacturing tolerances resulting in a misalignment between the mark and the end of the tubular component without the mark.

[0015] Therefore, there is a need for a connection that provides high torque and good sealing in a reliable manner. Summary

[0016] One idea underlying the invention is to provide a connection offering high torque and good sealing in a reliable manner. In particular, one idea underlying the invention is to position a relative positioning marker between two tubular components of a connection precisely and reliably. Thus, one idea underlying the invention is to take into account the structural elements of the threaded connection to determine a precise and reliable positioning of the relative positioning marker between the tubular components. Another idea underlying the invention is to use the actual characteristics of the connection and the tubular components to determine the positioning of the marker.

[0017] To this end, 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 an assembled state of the tubular connection, the first sealing surface and the second sealing surface being in hermetic contact in said assembled state of the tubular connection, characterized in that one of the first tubular component and the second tubular component comprises a marker, said marker having an optimal relative position between the first tubular component and the second tubular component, the optimal relative position of the marker being 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 frame is arranged, as well as a target torque of the tubular connection.

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

[0019] Thanks to these features, the reference mark used to control the relative position between the first and second tubular components in the assembled connection is positioned on the corresponding tubular component with a satisfactory degree of accuracy. Specifically, this positioning of the reference mark is determined by the actual characteristics of the tubular components and the tubular connection, and not by a theoretical position that would fail to account for the manufacturing tolerances of both the reference mark and the other characteristics of the tubular components and the connection.

[0020] Thus, a reference mark arranged according to the above characteristics ensures optimal relative positioning of the first and second tubular components. Specifically, such a reference mark, arranged according to the above characteristics, guarantees satisfactory relative positioning of the first and second sealing surfaces, ensuring a satisfactory seal of the connection in the assembled state. Furthermore, this proper positioning of the reference mark, and therefore of the sealing surfaces, ensures that no damage is caused by excessive interference on the sealing surfaces.

[0021] This corrected, optimal relative positioning of the tubular components also ensures that the male tubular component is not inserted too deeply into the female tubular component. Excessive insertion could cause the tubular connection to seize. Furthermore, such excessive insertion could lead to radial inward deformation of the end of the male tubular component, potentially preventing the passage of a measuring tool (hence the term "drift").

[0022] Such a reference mark, with its corrected optimal relative position, also ensures satisfactory tightening of the first and second tubular components without requiring a specific tightening curve. Indeed, tightening the tubular components until the distal end of the component without the reference mark is aligned with the reference mark is sufficient to guarantee that the tubular connection is in a satisfactory assembled state.

[0023] A connection according to the invention advantageously allows high levels of tensile and compressive forces to be supported in a simple and reliable manner, such a connection not requiring the presence of a thrust surface to support high levels of tensile and compressive forces.

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

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

[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 marker is arranged.

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

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

[0029] Preferably, said correction satisfies the equation: Correction = 1 ST × OD Wt CC × PdF in which ST is a tolerance threshold, OD is an external diameter of said one among the first tubular component and the second tubular component bearing the mark, Wt is a thickness of said one among the first tubular component and the second tubular component bearing 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 loading flank thread pitch and the thread pitch of the engagement flank thread pitch, for example the thread pitch of an engagement flank, or the thread pitch of a guide flank, belonging to said one among the first tubular component and the second tubular component bearing the mark.

[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.

[0031] 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.

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

[0033] In one embodiment, the corrected optimal relative position of the reference frame defines an optimal axial positioning of one distal end of the other between the first and second tubular components. In other words, the reference frame defines, by means of 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.

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

[0035] Such a lower tolerance zone allows for the definition of a range of relative positions between tubular components within which a loss of interference between the sealing surfaces is acceptable without significantly compromising the proper functioning of the tubular connection. For example, an interference loss between the first and second sealing surfaces of approximately 30% of the nominal interference in the assembled state of the connection, i.e., at the target torque, can be considered acceptable. In such a case, a tubular connection in the assembled state exhibiting an interference of at least 70% between the first and second sealing surfaces can be considered acceptable.This acceptable interference loss can be adapted according to the circumstances, for example according to 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.

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

[0037] This lower bound can be defined in many ways. For example, it can be defined arbitrarily, based on statistics of lower bounds considered acceptable. Preferably, this lower bound is determined based on the interference between the first and second sealing surfaces. Ideally, this lower bound is determined based on both the interference between the first and second sealing surfaces and the interference between the first and second threads.

[0038] According to one embodiment, the corrected lower bound satisfies the equation: borne inf é rieure = SI 2 × R 1 tan Max . ST 1 / ST 2 in which IF is a percentage of interference to the sealing, R1 is an acceptable interference loss, ST1 is an inclination of the first sealing surface, ST2 is an inclination of the second sealing surface.

[0039] In the case of a flat sealing surface, the ST1 or ST2 inclination of such a flat sealing surface corresponds to the angle formed between this flat sealing surface and the longitudinal axis of the tubular connection. In the case of a toroidal sealing surface, the inclination of said toroidal sealing surface corresponds to the angle formed by a straight line connecting the junction points of said toroidal sealing surface with the portions of the tubular component located axially on either side of said toroidal sealing surface.

[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: premi è re borne inf é rieure = SI 2 × R 1 tan Max . ST 1 / ST 2 , And si T i − premi è re borne inf é rieure × tan T T deg 2 < 0 , SO second lower bound = 0, and si Ti − premi è re borne inf é rieure × tan T T deg 2 ≥ 0 , SO deuxi è me borne inf é rieure = SI − premi è re borne inf é rieure × tan T T deg 2 2 × R 1 tan Max . ST 1 / ST 2 in which IFis a percentage of interference with the seal, R1 is an acceptable loss of tolerance 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.

[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 lower limit of great precision, guaranteeing precisely that a minimum interference is ensured between the sealing surfaces when, in the assembled state of the tubular connection, the distal end of the tubular component not having the mark is radially at the mark between the corrected optimal relative position and the lower tolerance zone.

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

[0043] According to one embodiment, the tubular connection further includes a higher tolerance zone.

[0044] Such a high tolerance zone defines a range of relative positions between the tubular components, ensuring that there is no damage caused by excessive interference between the sealing surfaces. Furthermore, this high tolerance zone ensures the absence of inward deformation of the tubular connection due to overtightening of the tubular components, as such deformation could impede the passage of a measuring tool (known as "drift").

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

[0046] This upper limit can be defined in many ways. For example, it can be defined arbitrarily, based on statistics of upper limits considered acceptable. Preferably, this upper limit is determined based on the interference between the first and second sealing surfaces. Ideally, this upper limit is determined based on both the interference between the first and second sealing surfaces and the interference between the first and second threads.

[0047] According to one embodiment, the upper bound satisfies the equation: borne sup é rieure = SI 2 × R 2 tan Max . ST 1 / ST 2 in which IF is a percentage of interference with the seal, R2 is an acceptable tolerance loss. ST1 is an inclination of the first sealing surface, ST2is an inclination of the second sealing surface.

[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: premi è re borne sup é rieure = SI 2 × R 2 tan Max . ST 1 / ST 2 , And si Ti − première borne supérieure × tan TT deg 2 < 0 , SO deuxi è me borne sup é rieure = 0 , And si Ti − première borne supérieure × tan TT deg 2 ≥ 0 , SO deuxi è me borne sup é rieure = SI − SI 2 × R 2 tan Max . ST 1 / ST 2 × tan TT deg 2 2 × R 2 tan Max . ST 1 / ST 2 in which SI is a percentage of interference to the sealing, R2 is an acceptable tolerance loss, ST1 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 and second threads, said one of the first and second threads being arranged on the tubular component having the mark, and Ti is a nominal interference between the first and second threads at the target torque of the connection.

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

[0050] Within a plurality of sealing surfaces on each of the tubular components, the lower and upper limits are defined as described above for each sealing zone of the tubular connection. Such sealing zones are formed by one of the first and one of the second cooperating sealing surfaces. The lower tolerance zone is then defined by the corrected optimal relative position and the minimum lower limit among all the lower limits. Similarly, the upper tolerance zone is then defined by the corrected optimal relative position and the minimum upper limit among all the upper limits. Brief description of the figures

[0051] The invention will be better understood, and other objects, details, features and advantages thereof will become more apparent from 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. [ Fig. 1 ] There figure 1 is a cross-sectional view of a tubular connection according to an embodiment of the invention. Fig. 2 ] There figure 2 is a schematic representation of an area of ​​the tubular connection illustrated on the figure 1 said area includes a reference mark for the relative positioning of the tubular components. Fig. 3 ] There figure 3 is a schematic representation of an initial variant of the tubular connection illustrated on the figure 1 illustrating an area of ​​said variant, said area comprising a reference mark for the relative positioning of the tubular components. Fig. 4 ] There figure 4is a schematic representation of a second variant of the tubular connection illustrated on the figure 1 illustrating an area of ​​said variant, said area comprising a reference for the relative positioning of the tubular components. Description of the implementation methods

[0052] In the description, figures, and 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 described as internal or radially internal as opposed to an element described as external or radially external located radially on the periphery.

[0054] Oil, gas, and other resource extraction requires a significant number of pipes, joined in pairs to form a wellhead. Due to the numerous stresses these pipes undergo during both installation and operation, they must adhere to specific standards to prevent degradation and leaks into the environment.

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

[0056] The first tubular component 2 comprises a first main body 4 and a first connecting portion 5. The first connecting portion 5 is formed on an external surface of the first tubular component 2, the first tubular component 2 thus being referred to as the "male" (or "pin"). The first connecting 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.

[0057] Similarly, the second tubular component 3 comprises a second main body 10 and a second connecting portion 11. The second connecting 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"). The second connecting 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.

[0058] As illustrated on the figure 1The first thread 8 comprises a plurality of first teeth 16. The first teeth 16 have a width, taken parallel to the X axis at an identical radial tooth height on each of said first teeth 16, that varies along the X axis. More particularly, said first teeth 16 have a width that increases along the X axis 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 ridge 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.

[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 and second directions thus being opposite with respect to the X axis. Likewise, 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.

[0061] There figure 1Figure 1 illustrates the tubular connection in the assembled state. This assembled state is achieved 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 specifically, 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 flanges 18 interfere with the second engagement flanges 23, and the first loading flanges 20 interfere with the second loading flanges 25.

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

[0063] 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 reference mark 26 is arranged on the first tubular component 2. More specifically, and as illustrated in the figure 2, this reference point 26 is arranged on the external surface of the first main body 4.

[0064] Reference point 26 has a nominal optimal relative position, that is, a theoretical position defined in the specifications for the manufacture of the first tubular component 2. This nominal optimal relative position is referred to as the nominal position in the following description. This nominal position defines a relative position between the first tubular component 2 and the second tubular component 3, and more specifically between the second free end 12 and the first tubular component 2, in which the various elements of the first tubular component 2 and the second tubular component 3, in particular the sealing surfaces 7, 9, 13 and 15, are positioned so as to ensure optimal operation of the tubular connection 1.

[0065] Reference element 26 further includes a nominal lower limit and a nominal upper limit which define, on either side of the nominal position, acceptable relative positioning zones between the tubular components 2 and 3. In the assembled state of the connection, the presence of the second free end 12 radially aligned with these relative positioning zones theoretically guarantees that the tubular connection 1 operates within acceptable limits, although not optimally. For example, these nominal lower and upper limits can define an acceptable interference loss between the sealing surfaces 7, 9, 13, and 15, or conversely, a maximum acceptable interference limit relative to optimal interference.

[0066] However, the reliability of this datum 26 is subject to the manufacturing tolerances of the first tubular component 2 and the second tubular component 3. In particular, datum 26 is affected 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 datum 26 are also themselves subject to manufacturing tolerances. Furthermore, the sealing surfaces 7, 9, 13, and 15 are also subject to manufacturing tolerances. Thus, there is some uncertainty regarding the reliability of datum 26 in indicating the correct relative positioning of the sealing surfaces 7, 9, 13, and 15.

[0067] The influence of manufacturing tolerances on reference mark 26 can lead to the validation of tubular connection 1 because the second free end 12 is radially aligned with reference mark 26, even though the sealing surfaces 7, 9, 13, and 15 do not cooperate acceptably. Conversely, the influence of manufacturing tolerances on reference mark 26 can lead to the rejection of tubular connections 1 because the second free end 12 is not radially aligned with reference mark 26, even though the sealing surfaces 7, 9, 13, and 15 cooperate acceptably.

[0068] To avoid this, the reference mark 26 according to the invention is positioned based on the actual parameters of the tubular components 2 and 3. Typically, the reference mark 26 is positioned on the first tubular component 2 based on the parameters of the first tubular component 2 and 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 the target torque CC, the percentage of interference to the 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, i.e., theoretical values.These nominal values ​​are taken at the target torque in the case of interference.

[0069] In particular, a corrected optimal relative position 27 is defined. The reference mark 26 is arranged on the first tubular component not according to the nominal position but according to this corrected optimal relative position 27, hereinafter referred to as the corrected position 27. This corrected position 27 is defined according to the nominal position defined in the specifications but also according to an external diameter OD of the first tubular component 2, a thickness Wt of the first tubular component 2, and 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; these are therefore the actual parameters of said first tubular component.

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

[0071] Thus, a positioning correction for the optimal relative position is calculated for the coordinate system. This correction is given by the equation: Correction = 1 ST × OD Wt CC × PdF in which ST is a tolerance threshold, OD is the external diameter of the first tubular component 2, Wt is the thickness of the first tubular component 2, CC is the target torque of 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.

[0072] The tolerance threshold ST can be determined in many ways. Preferably, this tolerance threshold ST can be arbitrarily determined, for example, to a value of 96000, this value being suitable for all 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," that is, the difference between the thread pitch of the engagement flanges and the thread pitches of the load-bearing flanges.

[0073] This equation allows us to obtain a displacement distance from the nominal position. Thus, the corrected position 27, and therefore the arrangement position of the reference frame 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.

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

[0075] Furthermore, the reference frame 26 arranged from the corrected position 27 has a corrected lower bound 28 and a corrected upper bound 29 which can be determined in many ways.

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

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

[0078] Preferably, in a manner analogous to the corrected position 27, the corrected lower bound 28 and / or the corrected upper bound 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.

[0079] Thus, the corrected lower bound 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 bound 29 is advantageously corrected as a function of the desired interference between the sealing surfaces 7, 9, 13 and 15.

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

[0081] In the context of a connection involving multiple seals as illustrated on the figure 1A corrected lower bound is determined for each seal to obtain a plurality of corrected lower bounds. The corrected lower bound used to define 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 seal, and the corrected upper bound used to define 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.

[0082] Thus, within the framework of the tubular connection illustrated on the figure 1comprising an internal seal formed jointly by the first internal seal surface 9 and the second internal seal surface 13, and an external seal formed jointly by the first external seal surface 7 and the second external seal 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 mark 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 mark 26 is then the smallest corrected upper limit among those determined for the internal seal and for the external seal.

[0083] The positioning of the corrected lower boundary and corrected upper boundary is described below in a generic way for a sealing zone, the description below being applicable to each of the different sealings.

[0084] According to an embodiment taking into account the actual interference between the sealing surfaces, the corrected lower bound 28 satisfies the equation: borne inf é rieure = SI 2 × R 1 tan Max . ST 1 / ST 2 in which IF is a percentage of interference to the sealing, R1 is an acceptable interference loss between the sealing surfaces, ST1 is an inclination of the first sealing surface, ST2 is an inclination of the second sealing surface.

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

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

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

[0088] An acceptable interference loss between sealing surfaces can 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 sealing surfaces is, for example, 30%, meaning that a minimum interference of 70% is ensured by the corrected lower limit.

[0089] Similarly, the upper bound satisfies the equation: borne sup é rieure = SI 2 × R 2 tan Max . ST 1 / ST 2 in which IF is the percentage of interference to the seal, R2 is the maximum acceptable interference between the sealing surfaces, ST1 is the inclination of the first sealing surface, ST2 is the inclination of the second sealing surface.

[0090] The maximum acceptable interference between sealing surfaces can be determined based on the shape of the sealing surfaces, the desired performance of the pipe connection, or other factors. This maximum acceptable interference between sealing surfaces is, for example, 40%.

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

[0092] According to a preferred embodiment taking into account the actual interference between the sealing surfaces but also the interference between the threads, the corrected lower bound is equal to a minimum value between a first corrected lower bound and a second corrected lower bound, said first corrected lower bound and second corrected lower bound satisfying the equations: premi è re borne inf é rieure = SI 2 × R 1 tan Max . ST 1 / ST 2 , And si T i − premi è re borne inf é rieure × tan T T deg 2 < 0 , SO deuxi è me borne inf é rieure = 0 , And si Ti − premi è re borne inf é rieure × tan T T deg 2 ≥ 0 , SO deuxi è me borne inf é rieure = SI − premi è re borne inf é rieure × tan T T deg 2 2 × R 1 tan Max . ST 1 / ST 2 in which IF is the percentage of interference with the seal, R1 is the acceptable loss of tolerance, ST1 is the inclination of the first sealing surface, ST2 is the inclination of the second sealing surface and TTdegis an inclination of the thread corresponding to the tubular component on which the reference 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.

[0093] Such a corrected lower limit, 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 corrected lower limit of great precision, guaranteeing precisely that a minimum interference is ensured in the assembled state of the tubular connection 1.

[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: premi è re borne sup é rieure = SI 2 × R 2 tan Max . ST 1 / ST 2 , And si Ti − première borne supérieure × tan TT deg 2 < 0 , SO deuxi è me borne sup é rieure = 0 , And si Ti − première borne supérieure × tan TT deg 2 ≥ 0 , SO deuxi è me borne sup é rieure = SI − SI 2 × R 2 tan Max . ST 1 / ST 2 × tan TT deg 2 2 × R 2 tan Max . ST 1 / ST 2 where SI is the percentage of interference to the sealing, R2 is the acceptable loss of tolerance between the sealing surfaces, ST1 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.

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

[0096] THE figures 1 and 2illustrate a tubular connection 1 in which the marker 26 is arranged on the external surface of the main body 4 of a first male-type tubular component 2 and allows said tubular connection to be validated according to the relative position of the second free end 12 with respect to the marker 26. However, the invention applies in an analogous way in the context of tubular connections having other configurations.

[0097] THE figures 3 and 4 illustrate such examples of other configurations, the above description with regard to reference mark 26, corrected position 27, corrected lower limit 28 and corrected upper limit 29 applying analogously in such other configurations of the tubular connection 1. On these figures 3 and 4 , elements identical to or fulfilling the same function as elements described above with regard to figures 1 and 2 They all have the same reference number. In the description below... figures 3 and 4only the elements different from those already described above with regard to the figures 1 and 2 are detailed, the elements not described opposite the figures 3 and 4 being identical to those already described with regard to the figures 1 and 2 .

[0098] There figure 3 illustrates the case of a tubular connection 1 called "flush", that is to say 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 reference mark 26 is arranged on the external surface of the first connection portion 5 of the first tubular component 1. More specifically, the reference mark 26 is arranged between the first main body 4 and the first external sealing surface (not illustrated).

[0099] There figure 4This illustrates the case of a tubular connection 1 in which the marker 26 is located on the internal surface of the second tubular component 3, i.e., on the female-type tubular component 3. This marker 26 then allows the tubular connection 1 to be validated or rejected depending on the relative position between the marker 26 and the first free end 6. Furthermore, the marker 26 is then located on the internal surface of the second connection portion 11 axially between the second main body 10 and the second internal sealing surface 13.

[0100] Only the elements relevant to the invention have been described with regard to the figures 1 to 4 The tubular connection may have other characteristics not described above. For example, the tubular connection illustrated on the figure 1includes an external groove to collect 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 regard to the figures 1 to 4 within the framework of preferred embodiments. However, the invention also covers embodiments not illustrated.

[0102] For example, the invention is applicable to integral or sleeve-coupled connections. In an integral connection, long tubular components have a male connecting element at one end and a female connecting element at the other, these long components being directly joined in pairs. In a sleeve-coupled connection, long tubular components have a male connecting element at each end, shorter tubular components called couplers have female connecting elements at each end, and two long tubular components are joined by means of a coupler.

[0103] Connections can be flush or semi-flush. A flush connection is one whose external diameter is no more than 101% of the external diameter of the body of the tubular component attached to the connection. A semi-flush connection is one whose external diameter is no more than 110% of the external diameter of the body of the tubular component attached to the connection.

[0104] Similarly, the invention is described above in the context of single threads, the invention being applicable in the context of threads having several threaded areas, for example on several stages.

[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.

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

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

[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 bound, and the corrected upper bound, is the minimum value between the lower bounds, respectively the bound between the upper bounds, calculated for each of the sealing zones.

[0109] The use of the verb "comporter", "comprendre" or "include" and its conjugated forms does not exclude the presence of other elements or steps than those stated in a claim.

[0110] In claims, any reference sign in parentheses shall not be interpreted as a limitation of the claim.

Claims

1. A 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 an assembled state of the tubular connection (1), the first sealing surface (7, 9) and the second sealing surface (13, 15) being in sealed contact in said assembled state of the tubular connection (1), characterized in that one out of the first tubular component (2) and the second tubular component (3) include a reference mark (26), said reference mark having an optimum relative position between the first tubular component (2) and the second tubular component (3), the optimum relative position of the reference mark (26) being a corrected optimum relative position (27), said corrected optimum relative position (27) corresponding to a nominal optimum relative position to which a correction is applied, said correction being a function of the characteristics of said one out of the first tubular component (2) and the second tubular component (3) on which the reference mark is arranged and of a target torque of the tubular connection (1).

2. The tubular connection (1) as claimed in claim 1, wherein the correction satisfies the equation: Correction = 1 ST × OD Wt CC × PdF in which ST is a tolerance threshold, OD is an outside diameter of said one out of the first tubular component (2) and the second tubular component (3) including the reference mark, (26), Wt is a thickness of said one out of the first tubular component (2) and the second tubular component (3) including the reference mark (26), CC is a target torque of the tubular connection (1), PdF is a thread pitch of the thread belonging to said one out of the first tubular component (2) and the second tubular component (3) including the reference mark (26).

3. The tubular connection (1) as claimed in claim 1 or 2, further comprising a lower tolerance zone.

4. The tubular connection (1) as claimed in claim 3, wherein said lower tolerance zone is determined on the one hand by the corrected optimal relative position (27) of the reference 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) in the direction of a free end (6, 12) of one out of the first tubular component (2) and the second tubular component (3) including the reference mark (26).

5. The tubular connection (1) as claimed in claim 4, wherein the corrected lower limit (28) satisfies the equation: lower limit = SI 2 × R 1 tan Max . ST 1 / ST 2 in which SI is a percentage of interference on sealing, R1 is an acceptable loss of interference, ST1 is an inclination of the first sealing surface (7, 9), ST2 is an inclination of the second sealing surface (13, 15).

6. The tubular connection (1) as claimed in claim 5, wherein the corrected lower limit is equal to a minimum value between a first lower limit and a second lower limit, said first lower limit and second lower limit satisfying the equations: first lower limit = SI 2 × R 1 tan Max . ST 1 / ST 2 , and if Ti − first lower limit × tan T T deg 2 < 0 , then second lower limit = 0 , and if Ti − first lower limit × tan T T deg 2 ≥ 0 , then second lower limit = SI − first limit × tan T T deg 2 2 × R 1 tan Max . ST 1 / ST 2 in which SI is a percentage of interference on sealing, R1 is an acceptable loss of tolerance, ST1 is an inclination of the first sealing surface, ST2 is an inclination of the second sealing surface and TTdeg is an inclination of one out of the first thread (8) and the second thread (14), said one out of the first thread (8) and the second thread (14) being arranged on the tubular component including the reference mark (26) and Ti is a nominal interference between the first thread and the second thread.

7. The tubular connection (1) as claimed in one of the preceding claims, further comprising an upper tolerance zone.

8. The tubular connection (1) as claimed in claim 7, wherein said upper tolerance zone is determined on the one hand by the corrected optimal relative position (27) of the reference 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 out of the first tubular component (2) and the second tubular component (3) including the reference mark (26).

9. The tubular connection as claimed in claim 8, wherein the upper limit satisfies the equation: upper limit = SI 2 × R 2 tan Max . ST 1 / ST 2 in which SI is a percentage of interference on sealing, R2 is an acceptable loss of tolerance, ST1 is an inclination of the first sealing surface (7, 9), ST2 is an inclination of the second sealing surface (13, 15).

10. The tubular connection (1) as claimed in claim 9, wherein the corrected upper limit (29) is equal to a minimum value between a first upper limit and a second upper limit, said first upper limit and second upper limit satisfying the equations: first upper limit = SI 2 × R 2 tan Max . ST 1 / ST 2 if Ti − first upper limit × tan TT deg 2 < 0 , then second upper limit = 0 , and if Ti − first upper limit × tan TT deg 2 ≥ 0 , then second upper limit = SI − SI 2 × R 2 tan Max . ST 1 / ST 2 × tan TT deg 2 2 × R 2 tan Max . ST 1 / ST 2 in which SI is a percentage of interference on sealing, R2 is an acceptable loss of tolerance, ST1 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 out of the first thread (8) and the second thread (14), said one out of the first thread (8) and the second thread (14) being arranged on the tubular component including the reference mark (26) and Ti is a nominal interference between the first thread and the second thread.

Images