Threaded tubular connection

Abstract

The invention relates to a tubular connection (1) comprising a first tubular part (2) and a second tubular part (3), the tubular parts (2, 3) each 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 engaged with each other when the tubular connection (1) is in an installed state, the sealing surfaces (7, 9, 13, 15) being in sealing contact when the tubular connection (1) is in an installed state, the tubular connection (1) comprising a reference mark (26) having an optimal relative position between the tubular parts (2, 3), characterized in that the optimal relative position corresponds to a corrected nominal optimal relative position, the correction depending on a property of one of the first tubular part (2) and the second tubular part (3) in which the reference mark is arranged and on a target torque of the tubular connection (1).

Description

Technical Field

[0001] This invention relates to the field of threaded connections for tubular components used in, for example, drilling, oil and gas well extraction, oil and gas transportation, fluid storage, and geothermal energy or CO2 capture. Background Technology

[0002] Threaded fittings for tubular components, such as those used in oil and gas well production tubing, comprise pairs of tubular components sealed together for conveying oil, gas, or other fluids. Each of these connected tubular components has a corresponding threaded end. This threaded end is formed on the inner surface of the tubular component in the case of a female (or "box-type") threaded end, or on the outer surface of the tubular component in the case of a male (or "pin-type") threaded end. These threaded ends are complementary in a manner that allows the tubular components to be screwed together in pairs.

[0003] The tubular components of a threaded fastener are assembled under predetermined stress conditions to meet the tightening and sealing requirements imposed by the operating conditions. When assembled in this way, the tubular components form what is known as a joint or connection in an assembled state.

[0004] In addition, during use, these threaded fasteners are subjected to axial tensile and / or compressive stresses, internal and / or external fluid pressures, bending, or torsion; these forces may combine and exhibit fluctuating intensity. Despite the stresses and harsh operating conditions in the field, it is essential to ensure the tightness of these threaded fasteners.

[0005] Threaded fasteners must also be able to be tightened and loosened several times without impairing their performance, especially without impairing their performance due to jamming. After loosening, these components can be reused under other operating conditions.

[0006] Document US20070158943 describes a threaded fastener with a self-locking thread having teeth of variable width, i.e., interference between the sides of the teeth of the thread. The threaded fastener described in US20070158943 also includes a metal-to-metal sealing surface. Such a fastener provides high torque while ensuring a good seal.

[0007] As stated in the aforementioned literature, it is important that the two tubular components forming the connector have a controlled relative position to ensure good interaction between the sealing surfaces and thus ensure a good seal of the connector. In particular, it is important that the screwing of the two tubular components allows sufficient interference between the two sealing surfaces to ensure a seal of the connector while preventing excessive interference that could lead to jamming and / or damage to the sealing surfaces.

[0008] To ensure proper relative positioning of the tubular components forming the connector, the connector described in US20070158943 also includes complementary stop surfaces located on the tubular components. The abutment of these stop surfaces ensures proper relative positioning between the tubular components forming the connector. However, such stop surfaces occupy significant radial space and thus limit the space available for other elements of the tubular components. Such stop surfaces also constitute stress concentration areas that may disrupt the normal functioning of the connector. Therefore, these stop surfaces are not entirely satisfactory for ensuring proper relative positioning of the tubular components in connectors that include teeth with variable widths, interfering threads, and dedicated sealing surfaces.

[0009] To avoid using a stop surface, it is also known to use a reference mark, such as a visual reference mark, on one of the tubular components of the connector. Typically, the tubular components are screwed together until a target tightening torque, hereinafter referred to as the target torque, is reached. This target torque corresponds to the torque obtained when the threaded connector is in the assembled state. If the end of the tubular component without a visual reference mark is aligned with the visual reference mark in the assembled state of the connector, the connector is considered to have satisfactory operating performance and is therefore accepted. Conversely, if the end of the tubular component without a visual reference mark is not aligned with the visual reference mark in the assembled state of the connector, the threaded connector is considered to have unsatisfactory operating performance and is therefore rejected.

[0010] Such visual reference marks are arranged on one of the tubular components according to their nominal positions. This nominal position of the reference mark is determined in a manner similar to other parameters of the connector, i.e., by means of the dimensions defined in the specifications of the connector and the tubular component. More specifically, this reference point is defined by the nominal optimal relative position between the tubular components and the nominal axial positioning tolerance on either side of this nominal optimal relative position.

[0011] However, as with other parameters of connectors and tubular components, the nominal position of the reference mark is affected by manufacturing tolerances. Typically, the nominal optimal relative position and nominal axial positioning tolerance are influenced by manufacturing tolerances in relation to their placement on the tubular component.

[0012] In addition, since other structural features of the tubular component are also affected by manufacturing tolerances, there is uncertainty regarding the precise relative position of the tubular component with respect to the reference mark when the connector is in an assembled state.

[0013] Specifically, tolerances involved in thread manufacturing, interference at the target tightening torque, and the position of the sealing surfaces can lead to situations where the target tightening torque is achieved, and the end of a tubular component without a reference mark is aligned with the reference mark, but the sealing surfaces are not properly positioned, thus failing to ensure a good seal at the connection. Therefore, even if the sealing surfaces are not correctly positioned relative to each other, an unsatisfactory assembly of the connection may be acceptable because manufacturing tolerances cause the position of the reference mark to correspond to the position of the end of the tubular component excluding the reference mark. This incorrect relative positioning of the sealing surfaces can result in either excessively small interference or, conversely, excessively large interference between the sealing surfaces, leading to sealing defects or jamming, or even damage to the sealing surfaces.

[0014] Conversely, a situation may arise where the target tightening torque is reached, and even though the sealing surface is correctly positioned, the free end of the tubular component excluding the reference mark is not aligned with the reference mark. In other words, satisfactory assembly conditions may be rejected due to a mismatch between the position of the reference mark and the end of the tubular component excluding the reference mark caused by manufacturing tolerances.

[0015] Therefore, it is necessary to reliably provide high torque and well-sealed connectors. Summary of the Invention

[0016] The fundamental concept of this invention is to provide a connector that reliably provides high torque and a good seal. Specifically, the fundamental concept is to accurately and reliably position a reference mark for relative positioning between two tubular components of the connector. Therefore, the fundamental concept of this invention considers structural elements of threaded connectors for accurately and reliably positioning the reference mark for relative positioning between the tubular components. The fundamental concept is to use the actual characteristics of the connector and the tubular components to determine the position of the reference mark.

[0017] Therefore, the present invention provides a tubular connector, which includes a first tubular component and a second tubular component.

[0018] The first tubular component includes a first thread and a first sealing surface, the first thread having a variable tooth width.

[0019] The second tubular component includes a second thread and a second sealing surface, the second thread having a variable tooth width.

[0020] The first thread and the second thread engage in the assembled state of the tubular connector, and the first sealing surface and the second sealing surface make sealing contact in the assembled state of the tubular connector.

[0021] One of the first tubular component and the second tubular component includes a reference mark, the reference mark having an optimal relative position between the first tubular component and the second tubular component.

[0022] The feature is that the optimal relative position of the reference mark is a corrected optimal relative position, which corresponds to a nominal optimal relative position to which correction has been applied, the correction depending on the characteristics of the first tubular component and the second tubular component in which the reference mark is arranged and the target torque of the tubular connector.

[0023] A thread with variable tooth width has teeth whose width, taken along the axial direction of the tubular component, increases in a direction oriented from the free end of the component toward the body of the tubular component. This tooth width is achieved at the same height on consecutive teeth, excluding imperfect teeth, for example, at the level of the width at the top of the tooth. This variation in tooth width is achieved by means of a difference in the thread pitch on the tooth flanks; for example, the thread pitch on the insertion flank of the tooth is greater than the thread pitch on the load flank of the tooth.

[0024] With the aid of these features, reference marks for controlling the relative position between the first and second tubular components in the assembled state of the connector are arranged on the corresponding tubular components with satisfactory accuracy. In particular, the position of the reference marks is determined by the actual characteristics of the tubular components and the tubular connector, rather than by a theoretical position that does not take into account the manufacturing tolerances of the reference marks or other characteristics of the tubular components and the connector.

[0025] Therefore, the reference markings arranged according to the above-described features ensure proper and optimal relative positioning of the first tubular component and the second tubular component. In particular, such reference markings arranged according to the above-described features ensure satisfactory relative positioning of the first sealing surface and the second sealing surface, thereby ensuring a satisfactory seal of the connector in the assembled state. Furthermore, this correct positioning of the reference markings and thus the sealing surfaces ensures that no damage due to excessive interference on the sealing surfaces will occur.

[0026] This calibrated optimal relative positioning of the tubular components also ensures that the male tubular component is not over-inserted into the female tubular component. Such over-insertion could cause the tubular connector to jam. Furthermore, such over-insertion could cause the end of the male tubular component to deform radially inward, which could prevent the passage of a control tool (“gauge”).

[0027] This reference point, with its corrected optimal relative position, also ensures satisfactory tightening of the first and second tubular components without having to follow a tightening curve. Specifically, the tubular components are tightened until the relative position of the distal end of the tubular component (excluding the reference mark) at the reference mark is sufficient to guarantee a satisfactory assembly of the tubular connector.

[0028] The connector according to the invention advantageously allows for the simple and reliable bearing of high levels of tensile and compressive forces, without the need for a stop surface to withstand such high levels of tensile and compressive forces.

[0029] According to an embodiment, such a tubular connector may include one or more of the following features, either individually or in combination.

[0030] According to an embodiment, the correction is based on the outer diameter of one of the first tubular component and the second tubular component on which a reference mark is arranged.

[0031] According to an embodiment, the correction is based on the radial thickness of one of the first tubular component and the second tubular component on which a reference mark is arranged.

[0032] According to one embodiment, the correction is based on the thread pitch of one of the first tubular component and the second tubular component, on which a reference mark is arranged. According to another embodiment, the thread pitch is the thread pitch on the insertion side of the thread of the first tubular component and the second tubular component, including the reference mark. According to yet another embodiment, the thread pitch is the thread pitch on the load side of the thread of the first tubular component and the second tubular component, including the reference mark.

[0033] According to the implementation method, the target torque is corrected based on the tubular connector.

[0034] Preferably, the correction satisfies the following equation:

[0035]

[0036] Wherein, ST is the tolerance threshold, OD is the outer diameter of the first tubular component and the second tubular component including the reference mark, Wt is the thickness of the first tubular component and the second tubular component including the reference mark, CC is the target torque of the tubular connector, and PdF is the thread pitch of the thread of the first tubular component and the second tubular component including the reference mark, preferably the maximum thread pitch of the load side and the insertion side, for example, the thread pitch of the insertion side or the thread pitch of the guide side.

[0037] According to an embodiment, the first thread includes a plurality of first teeth, each first tooth having a width cut along the longitudinal axis of the tubular connector, the width increasing in a first direction along the axis of the tubular connector.

[0038] According to an embodiment, the second thread includes a plurality of second teeth having a width cut along the longitudinal axis of the tubular connector, the width increasing in a second direction along the axis of the connector, the first direction being opposite to the second direction.

[0039] Preferably, the first direction is oriented from the distal end of the first tubular member toward the body of the first tubular member. Furthermore, the second direction is oriented from the distal end of the second tubular member toward the body of the second tubular member.

[0040] According to the embodiment, the corrected optimal relative position of the reference mark defines the optimal axial position of the distal end of the other of the first and second tubular components. In other words, the reference mark, by virtue of the corrected optimal relative position on one of the tubular components, defines the position at which the distal end of the other tubular component must stop in order to obtain a satisfactory tubular connector in the assembled state.

[0041] According to the implementation method, the tubular connector includes a lower tolerance region.

[0042] This lower tolerance zone allows for defining an area of ​​relative position between tubular components where interference loss between sealing surfaces is acceptable without significantly impairing the normal function of the tubular connector. For example, it can be considered acceptable that the interference loss between the first and second sealing surfaces is approximately 30% compared to the nominal interference in the assembled state of the connector, i.e., under the target torque. In this case, it can be considered acceptable that the tubular connector in the assembled state has at least 70% interference between the first and second sealing surfaces. This acceptable interference loss can be adjusted as needed, for example, based on the shape of the first and / or second sealing surfaces, the presence of one or more other seals in the tubular connector, the expected operating conditions, or any other reason.

[0043] According to the implementation, the lower tolerance region is determined on the one hand by the corrected optimal relative position of the reference mark and on the other hand by the correction lower limit. The lower tolerance region extends a corresponding distance from the corrected optimal relative position to the correction lower limit in the direction of the distal end of the first tubular component and the second tubular component, including the reference mark.

[0044] This lower limit can be defined in many ways. For example, it can be arbitrarily defined based on statistical data that is considered an acceptable lower limit. Preferably, the lower limit is determined based on the interference between the first sealing surface and the second sealing surface. Ideally, the lower limit is determined based on the interference between the first sealing surface and the second sealing surface on one hand, and on the interference between the first thread and the second thread on the other hand.

[0045] According to the implementation method, the lower limit of correction satisfies the following equation:

[0046]

[0047] Where SI is the percentage of interference with the seal, R1 is the acceptable interference loss, ST1 is the inclination of the first sealing surface, and ST2 is the inclination of the second sealing surface.

[0048] In the case of a flat sealing surface, the inclination ST1 or ST2 of this flat sealing surface corresponds to the angle formed between the flat sealing surface and the longitudinal axis of the tubular connector. In the case of an annular sealing surface, the inclination of the annular sealing surface corresponds to the angle formed by the straight line connecting the joint point of the annular sealing surface and the portion of the tubular component located on either side of the annular sealing surface in the axial direction.

[0049] According to the implementation method, the correction lower limit is equal to the minimum value between the first lower limit and the second lower limit, and the first lower limit and the second lower limit satisfy the following equation:

[0050] (1) as well as

[0051] (2) If but

[0052] The second lower limit = 0, and

[0053] if but

[0054]

[0055] Where SI is the percentage of interference with respect to the seal, R1 is the acceptable tolerance loss, ST1 is the inclination of the first sealing surface, ST2 is the inclination of the second sealing surface, TTdeg is the inclination of one of the first and second threads, said one of the first and second threads being arranged on a tubular component including a reference mark, and Ti is the nominal interference between the first and second threads at the target torque.

[0056] This lower limit takes into account both the interference between sealing surfaces and the interference between threads, allowing for the determination of a very precise lower limit. This ensures that when the distal end of the tubular component (excluding the reference mark) is radially aligned with the reference mark in the corrected optimal relative position and the lower tolerance area in the assembled state of the tubular connector, minimum interference between the sealing surfaces is guaranteed.

[0057] In the case of a tubular connector where the top and / or root of its thread teeth are inclined relative to the longitudinal axis of the connector, the inclination of the thread corresponds to the inclination of the top and / or root. In the case of a tubular connector where the top and root of its thread teeth are parallel to the longitudinal axis of the tubular connector, the inclination of the thread corresponds to the inclination of a straight line passing through the same point at the root or top of consecutive teeth. Teeth with singularities, such as imperfect teeth that are not allowed to define corresponding points on this straight line, are ignored in the definition of this inclination.

[0058] According to the implementation method, the tubular connector also includes an upper tolerance region.

[0059] This upper tolerance area defines the relative positions between tubular components, ensuring that damage is not caused by excessive interference between sealing surfaces. Additionally, this upper tolerance area prevents the tubular connectors from deforming inwards due to excessive screwing, as such deformation would impede the passage of control tools (“gauges”).

[0060] According to the embodiment, the upper tolerance region is determined on the one hand by the corrected optimal relative position of the reference mark and on the other hand by the upper limit. The upper tolerance region extends a corresponding distance from the corrected optimal relative position to the upper limit in the direction of moving away from the free end of the first tubular component and the second tubular component, including the reference mark.

[0061] This upper limit can be defined in many ways. For example, it can be arbitrarily defined based on statistical data that is considered an acceptable upper limit. Preferably, the upper limit is determined based on the interference between the first sealing surface and the second sealing surface. Ideally, the upper limit is determined on the one hand based on the interference between the first sealing surface and the second sealing surface, and on the other hand based on the interference between the first thread and the second thread.

[0062] According to the implementation method, the upper limit satisfies the following equation:

[0063]

[0064] Where SI is the percentage of interference with the seal, R2 is the acceptable tolerance loss, ST1 is the inclination of the first sealing surface, and ST2 is the inclination of the second sealing surface.

[0065] According to the implementation method, the upper limit is equal to the minimum value between the first upper limit and the second upper limit, and the first upper limit and the second upper limit satisfy the following equation:

[0066] (3) as well as

[0067] (4) If but

[0068] The second upper limit = 0, and

[0069] if but

[0070]

[0071] Where SI is the percentage of interference with respect to the seal, R2 is the acceptable tolerance loss, ST1 is the inclination of the first sealing surface, ST2 is the inclination of the second sealing surface, TTdeg is the inclination of one of the first and second threads, which is arranged on a tubular component including a reference mark, and Ti is the nominal interference between the first and second threads under the target torque of the connector.

[0072] According to an embodiment, the first tubular component has a plurality of first sealing surfaces, and the second tubular component has a plurality of second sealing surfaces.

[0073] In the case of multiple sealing surfaces on each tubular component, each sealing region of the tubular connector is defined with a lower limit and an upper limit as described above, such a sealing region being formed by the interaction of one of the first sealing surfaces and one of the second sealing surfaces. The lower tolerance region is then defined by the corrected optimal relative position and the minimum lower limit in the set of lower limits. Similarly, the upper tolerance region is then defined by the corrected optimal relative position and the minimum upper limit in the set of upper limits. Attached Figure Description

[0074] The invention will be better understood from the following description of several specific embodiments provided by way of non-limiting illustration only, with reference to the accompanying drawings, and other objects, details, features and advantages of the invention will become more apparent.

[0075] [ Figure 1 ] Figure 1 This is a cross-sectional view of a tubular connector according to an embodiment of the present invention.

[0076] [ Figure 2 ] Figure 2 schematically depicted Figure 1The area shown is a tubular connector, which includes reference marks for the relative positioning of the tubular components.

[0077] [ Figure 3 ] Figure 3 schematically depicted Figure 1 The diagram shows a first variant of the tubular connector, depicting a region of the variant that includes reference marks for the relative positioning of the tubular components.

[0078] [ Figure 4 ] Figure 4 schematically depicted Figure 1 The diagram shows a second variant of the tubular connector, depicting a region of the variant that includes reference marks for the relative positioning of the tubular components. Detailed Implementation

[0079] In the specification, drawings, and claims, axis X corresponds to the axis of rotation of the tubular component in the assembled state of the tubular connector, and axis X also defines the axis of the tubular connector. By convention, the "radial" orientation is orthogonal to axis X and the "axial" orientation is parallel to axis X.

[0080] The terms "external" and "internal" are used to define the relative position of an element with respect to the axis X. Therefore, in contrast to elements located on the periphery in the radial direction, which are considered external or radially external elements, elements closer to the axis X are considered internal or radially internal elements.

[0081] Oil, gas, or other extraction requires numerous pairs of connected pipes to form a tubing string in the production well. Because these pipes are subjected to many stresses during both their installation and operation, they are compliant with standards to prevent any damage and any leakage into the environment.

[0082] Figure 1 A cross-sectional view of a tubular connector 1 according to an embodiment of the present invention is shown. The tubular connector 1 is formed by assembling a first tubular component 2 and a second tubular component 3.

[0083] The first tubular component 2 includes a first body 4 and a first connecting portion 5. The first connecting portion 5 is formed on the outer surface of the first tubular component 2, and the first tubular component 2 is therefore referred to as a "male" (or "pin"). The first connecting portion 5, from the first body 4 to the first free end 6 of the first tubular component 2, sequentially includes a first outer sealing surface 7, a first thread 8, a first inner sealing surface 9, and then the first free end 6 of the first tubular component 2.

[0084] Similarly, the second tubular component 3 includes a second body 10 and a second connecting portion 11. The second connecting portion 11 is formed on the inner surface of the second tubular component 3, which is therefore referred to as a "female" (or "box-shaped" component). The second connecting portion 11 includes, from the second body 10 to the second free end 12 of the second tubular component 3, a second inner sealing surface 13, a second thread 14, a second outer sealing surface 15, and then the second free end 12.

[0085] like Figure 1 As shown, the first thread 8 includes a plurality of first teeth 16. Each of the first teeth 16 has a width obtained at the same radial tooth height parallel to the axis X, which is variable along the axis X. More specifically, the first teeth 16 have an increasing width along the axis X in a first direction oriented from the first free end 6 toward the first body 4.

[0086] The first tooth 16 has a first root 17, a first insertion side 18, a first top 19, and a first load side 20. The first insertion side 18 faces the first free end 6. The first load side 20 faces the first body 4.

[0087] Similarly, the second thread 14 includes a plurality of second teeth 21 with variable tooth widths, the second teeth 21 having an increasing width in a second direction oriented from the second free end 12 toward the second body 10, thus the first and second directions are opposite to the axis X. Likewise, the second teeth 21 have a second root 22, a second insertion side 23 facing the second free end 12, a second top 24, and a second load side 25 facing the second body 10.

[0088] Figure 1 The tubular connector 1 in an assembled state is shown. This assembled state is achieved by screwing the first tubular component 2 and the second tubular component 3 together. During this screwing, the first tooth 16 engages with the second tooth 21. More specifically, in the assembled state, the first tooth 16 and the second tooth 21 engage in an interference manner. Therefore, in the assembled state, the first insertion side 18 interferes with the second insertion side 23, and the first load side 20 interferes with the second load side 25.

[0089] Similarly, in this assembled state, the first inner sealing surface 9 and the second inner sealing surface 13 interfere with each other to ensure a good seal for the tubular connector 1, particularly for the fluid circulating inside the tubular connector 1. The first outer sealing surface 7 and the second outer sealing surface 15 also interfere with each other to ensure a good seal for the tubular connector 1, particularly for the fluid outside the tubular connector 1.

[0090] To ensure the correct relative positioning of the first tubular component 2 and the second tubular component 3 in the assembled state, and particularly the correct relative positioning of the sealing surfaces 7, 9, 13, and 15, reference marks 26 are arranged on the first tubular component 2. More specifically, and as shown in Figure 2 As shown, the reference mark 26 is arranged on the outer surface of the first body 4.

[0091] Reference numeral 26 includes a nominal optimal relative position, that is, a theoretical position defined in the specification intended for manufacturing the first tubular component 2, which is referred to as the nominal position in the remainder of the specification. This nominal position defines the relative position between the first tubular component 2 and the second tubular component 3, and more specifically, the relative position 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, particularly the sealing surfaces 7, 9, 13, and 15, are positioned in a manner that ensures optimal function of the tubular connector 1.

[0092] Reference numeral 26 also includes a nominal lower limit and a nominal upper limit, which define an acceptable area for relative positioning between tubular components 2 and 3 on either side of the nominal position. In the assembled state of the connector, the radial alignment of the second free end 12 with these relative positioning areas theoretically guarantees the function of the tubular connector 1, which, while not optimal, remains within acceptable operating limits. For example, these nominal lower and upper limits may define acceptable interference loss between sealing surfaces 7, 9, 13, and 15, or conversely, define the maximum interference limit acceptable with respect to optimal interference.

[0093] However, the reliability of the reference mark 26 is affected by the manufacturing tolerances of the first tubular component 2 and the second tubular component 3. Specifically, the reference mark 26 is affected by the manufacturing tolerances of threads 8 and 14, which influence the degree of interference between sides 18, 20, 23, and 25, and thus the relative position between the first tubular component 2 and the second tubular component 3. The nominal position, upper nominal limit, and lower nominal limit defining the reference mark 26 are also themselves affected by manufacturing tolerances. Furthermore, the sealing surfaces 7, 9, 13, and 15 are also affected by manufacturing tolerances. Therefore, there is uncertainty regarding the reliability of the reference mark 26 in indicating the correct relative positioning of the sealing surfaces 7, 9, 13, and 15.

[0094] The effect of manufacturing tolerances on reference mark 26 may lead to the acceptance of tubular connector 1 because, even though sealing surfaces 7, 9, 13, and 15 do not interact in an acceptable manner, the second free end 12 is arranged radially aligned with reference mark 26. Conversely, the effect of manufacturing tolerances on reference mark 26 may lead to the rejection of tubular connector 1 because, even though sealing surfaces 7, 9, 13, and 15 interact in an acceptable manner, the second free end 12 is not radially aligned with reference mark 26.

[0095] To avoid this situation, according to the invention, reference mark 26 is positioned based on the actual parameters of tubular components 2 and 3. Typically, 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, parameters which are measured, calculated, or obtained by any other means. Therefore, the parameter used in the following equation relating to one of the tubular components 2 or 3 is the actual parameter of said tubular component 2 or 3, for example, measured after manufacture. However, parameters relating to the tubular connector 1, such as the target torque CC, the percentage of interference SI with respect to the seal, or the interference Ti between the first thread 8 and the second thread 14, are nominal values, i.e., theoretical values, of the tubular connector 1. These nominal values ​​are obtained at the target torque under interference conditions.

[0096] Specifically, a corrected optimal relative position 27 is defined. Reference numeral 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 not only according to the nominal position defined in the application, but also according to the outer diameter OD of the first tubular component 2, the thickness Wt of the first tubular component 2, and the thread pitch Pdf of the first thread 8. After the first tubular component 2 is manufactured, the outer diameter OD, thickness Wt, and thread pitch Pdf are measured, calculated, or obtained on the first tubular component 2 by any other means; therefore, these are the actual parameters of the first tubular component.

[0097] The calibration position 27 is also positioned according to the target torque CC of the tubular connector 1.

[0098] Therefore, a positioning correction for the optimal relative position is calculated with respect to the reference marker. This correction satisfies the following equation:

[0099]

[0100] Where ST is the 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 connector 2, and PdF is the thread pitch of the first thread 8, preferably the larger of the thread pitch on the load side and the thread pitch on the insertion side of the first thread 8.

[0101] The tolerance threshold ST can be determined in many ways. Preferably, the tolerance threshold ST can be arbitrarily determined, for example, at a value of 96000, which applies to all connectors according to the invention. The tolerance threshold ST can also be calculated by analyzing the thread inclination and thread pitch, particularly the "wedge ratio," i.e., the difference between the thread pitch on the insertion side and the thread pitch on the load side.

[0102] This equation allows the displacement distance relative to the nominal position to be obtained. Therefore, the corrected position 27 is obtained by applying an offset with a value corresponding to the obtained correction to the nominal position, and thus the position in which the reference mark 26 is arranged on the first tubular member 2 is obtained.

[0103] This correction allows for precise and reliable positioning of the reference mark 26. In particular, the correction position 27 takes into account the manufacturing tolerances of the first tubular component 2 and the tubular connector 1, such that the correction position 27 corresponds to the relative position of the second free end 12 with respect to the reference mark 26, in which the sealing surfaces 7, 9, 13 and 15 are actually correctly positioned to ensure the seal of the tubular connector 1.

[0104] Furthermore, the reference mark 26 arranged based on the correction position 27 includes a lower correction limit 28 and a higher correction limit 29 that can be determined in various ways.

[0105] For example, the lower correction limit 28 and / or the upper correction limit 29 can be determined by the nominal lower limit and / or the nominal upper limit, respectively. In this case, the reference mark 26 includes the upper tolerance region and the lower tolerance region determined by the correction position 27 and these nominal limits.

[0106] Alternatively, the lower correction limit 28 and / or the upper correction limit 29 can be determined based on acceptable limiting statistics.

[0107] Preferably, like the correction position 27, the lower correction limit 28 and / or the upper correction limit 29 are also determined based on the actual structural parameters of the tubular connector 1 to further improve the reliability and accuracy of the reference mark 26.

[0108] Therefore, the lower correction limit 28 is advantageously determined based on the desired minimum interference between sealing surfaces 7, 9, 13 and 15. Similarly, the upper correction limit 29 is advantageously corrected based on the desired interference between sealing surfaces 7, 9, 13 and 15.

[0109] Ideally, the lower limit is determined not only by the desired minimum interference between sealing surfaces 7, 9, 13, and 15, but also by the interference between threads 8 and 14. Similarly, ideally, the upper limit 29 is determined not only by the desired interference between sealing surfaces 7, 9, 13, and 15, but also by the interference between threads 8 and 14.

[0110] Including, such as Figure 1 In the case of a connector with multiple seals shown, a lower correction limit is determined for each seal to obtain multiple lower correction limits. The lower correction limit used to define reference point 26 is then the smallest of these multiple lower correction limits. Similarly, an upper correction limit is calculated for each seal, and the upper correction limit used to define reference 26 is the smallest of the multiple upper correction limits obtained based on the multiple seals.

[0111] Therefore, in Figure 1 In the case where the tubular connector shown includes an inner seal formed by a first inner sealing surface 9 and a second inner sealing surface 13, and an outer seal formed by a first outer sealing surface 7 and a second outer sealing surface 15, a correction limit is determined for the inner seal and a correction limit is determined for the outer seal. Then, the lower correction limit 28 of reference numeral 26 is the smallest of those lower correction limits determined for the inner and outer seals. Similarly, the upper correction limit 29 of reference numeral 26 is the smallest upper correction limit determined for the inner and outer seals.

[0112] The following description generally refers to the location of the lower and upper correction limits for the sealing area. This description is applicable to each seal in different types of seals.

[0113] According to the implementation method that takes into account the actual interference between the sealing surfaces, the lower correction limit 28 satisfies the following equation:

[0114]

[0115] Where SI is the percentage of interference with the seal, R1 is the acceptable tolerance loss between the sealing surfaces, ST1 is the inclination of the first sealing surface, and ST2 is the inclination of the second sealing surface.

[0116] Therefore, such a lower limit 28 takes into account the effect of the expected actual interference between the sealing surfaces to accept or reject the tubular connector 1.

[0117] In the case of a flat sealing surface, the inclination of this flat sealing surface corresponds to the angle formed between the flat sealing surface and the axis X of the tubular connector 1.

[0118] In the case of annular sealing surfaces, the inclination of the annular sealing surface corresponds to the angle formed by a straight line connecting the joint point of the annular sealing surface and the portion of the tubular component located on either side of the annular sealing surface in the axial direction.

[0119] The acceptable interference loss between the sealing surfaces can be determined based on the shape of the sealing surfaces, the desired performance of the tubular connector 1, or any other reason. This interference loss between the sealing surfaces is, for example, 30%, meaning that a minimum interference of 70% is ensured by adjusting for a lower limit.

[0120] Similarly, the upper limit satisfies the following equation:

[0121]

[0122] Where SI is the percentage of interference with respect to the seal, R2 is the maximum acceptable interference between the sealing surfaces, ST1 is the inclination of the first sealing surface, and ST2 is the inclination of the second sealing surface.

[0123] The maximum acceptable interference between sealing surfaces can be determined based on the shape of the sealing surfaces, the desired performance of the tubular connection, or any other reason. This maximum acceptable interference between sealing surfaces is, for example, 40%.

[0124] Therefore, this upper limit of correction takes into account the effect of the expected actual interference between the sealing surfaces to accept or reject the tubular connector 1.

[0125] According to a preferred embodiment that considers not only the actual interference between sealing surfaces but also the interference between threads, the lower correction limit is equal to the minimum value between the first lower correction limit and the second lower correction limit, and the first lower correction limit and the second lower correction limit satisfy the following equation:

[0126] (1) as well as

[0127] (2) If but

[0128] The second lower limit = 0, and

[0129] if but

[0130]

[0131] Where SI is the percentage of interference with respect to the seal, R1 is the acceptable tolerance loss, ST1 is the inclination of the first sealing surface, ST2 is the inclination of the second sealing surface, TTdeg is the inclination of the thread corresponding to the tubular component on which reference mark 26 is arranged, and Ti is the nominal interference between the first and second threads under the target torque of the connector.

[0132] This lower limit of correction takes into account both the interference of the sealing surface and the interference between the threads, making it possible to determine a very precise lower limit of correction, thereby ensuring minimal interference in the assembled state of the tubular connector 1.

[0133] Similarly, the upper limit of correction is equal to the minimum between the first upper limit of correction and the second upper limit of correction, and the first upper limit of correction and the second upper limit of correction satisfy the following equation:

[0134] (3) as well as

[0135] (4) If but

[0136] The second upper limit = 0, and

[0137] if but

[0138]

[0139] Where SI is the percentage of interference with respect to the seal, R2 is the acceptable tolerance loss between the sealing surfaces, ST1 is the inclination of the first sealing surface, ST2 is the inclination of the second sealing surface, TTdeg is the inclination of the thread corresponding to the tubular component on which reference mark 26 is arranged, and Ti is the nominal interference between the first and second threads under the target torque of the connector.

[0140] In this preferred embodiment, the effects of the expected actual interference between the sealing surfaces and the actual interference between the threads are taken into account to reliably and accurately accept or reject the tubular connection.

[0141] Figure 1 and Figure 2 A tubular connector 1 is shown, wherein a reference mark 26 is arranged on the outer surface of the body 4 of the male first tubular member 2, and the tubular connector is received according to the relative position of the second free end 12 with respect to the reference mark 26. However, the invention is equally applicable to tubular connectors having other configurations.

[0142] Figure 3 and Figure 4Other configurations illustrating such examples, the descriptions above regarding reference mark 26, correction position 27, lower correction limit 28, and upper correction limit 29 also apply to other configurations of such tubular connectors 1. Figure 3 and Figure 4 In the middle, and above about Figure 1 and Figure 2 Elements that are identical in description or perform the same function have the same reference numerals. Figure 3 and Figure 4 The following description only details the information related to the above. Figure 1 and Figure 2 The components that have already been described are different components, regarding Figure 3 and Figure 4 Components not described and about Figure 1 and Figure 2 The components already described are the same.

[0143] Figure 3 The illustration depicts a tubular connector 1 referred to as "flush type," meaning that the outer diameter of the tubular connector 1 is 101% smaller than the outer diameters of the tubular components 2 and 3 forming it. In this tubular connector 1, reference mark 26 is arranged on the outer surface of the first connecting portion 5 of the first tubular component 1. More specifically, reference mark 26 is arranged between the first body 4 and the first outer sealing surface (not shown).

[0144] Figure 4 The illustration depicts a tubular connector 1 disposed on the inner surface of the second tubular member 3, that is, on the female tubular member 3. This reference mark 26 allows the tubular connector 1 to be accepted or rejected based on its relative position to the first free end 6. Furthermore, the reference mark 26 is then disposed on the inner surface of the second connecting portion 11, axially located between the second body 10 and the second inner sealing surface 13.

[0145] about Figures 1 to 4 Only elements relevant to this invention have been described; the tubular connector may also include other features not described above. Thus, for example, Figure 1 The tubular connector shown includes an outer groove for collecting grease that can be applied to the tubular component, and the first tubular component may include a face connecting the free end of the first tubular component and a chamfer on the inner surface of the first tubular component.

[0146] The above refers to the preferred embodiments. Figures 1 to 4 The present invention has been described. However, the present invention also covers embodiments not illustrated.

[0147] For example, the present invention is applicable to integral connectors or sleeve-type connectors. In an integral connector, a long tubular member has a male connecting element at a first end and a female connecting element at the other end, and these long members are assembled directly in pairs. In a sleeve-type connector, a long tubular member has a male connecting element at each end, and a shorter tubular member, referred to as a connector, has a female connecting element at each end; the two long tubular members are connected by means of the connector.

[0148] The connector can be flush or semi-flush. A flush connector is one whose outer diameter is at most 101% of the outer diameter of the body of the tubular component to which it is attached. A semi-flush connector is one whose outer diameter is at most 110% of the outer diameter of the body of the tubular component to which it is attached.

[0149] Similarly, while the invention has been described above in the case of a single-threaded thread, it is also applicable to threads that include several threaded regions at several levels.

[0150] The present invention is also applicable to tubular connectors that include, for example, one or more sealing regions located on either side of the thread and / or include a central sealing region.

[0151] Similarly, the root and tip of the thread teeth can be parallel to the axis of the tubular connector or parallel to the inclination of the thread. Such teeth can have a dovetail or trapezoidal profile.

[0152] Reference marks can be manufactured in various ways. Therefore, such reference marks can be manufactured, for example, by knurling, by machining grooves to form visual reference marks, by laser marking, by coating, by stamping reference marks, etc.

[0153] In the case where the tubular connector includes multiple first sealing surfaces and multiple corresponding second sealing surfaces forming different sealing areas in pairs, the lower correction limit and the upper correction limit are the minimum values ​​between the lower limits and the minimum values ​​between the upper limits calculated for each sealing area in the sealing area, respectively.

[0154] Although the invention has been described in conjunction with several specific embodiments, it is apparent that the invention is by no means limited thereto, and that the invention includes all technical equivalents of the described apparatus and combinations thereof where they fall within the scope of the invention.

[0155] The use of the verbs “comprising” or “including” and their combined forms does not exclude the presence of other elements or steps besides those set forth in the claims.

[0156] Any reference numerals in parentheses in the claims should not be construed as limiting the claims.

Claims

1. A tubular connection (1) comprising a first tubular part (2) and a second tubular part (3), the first tubular part (2) comprising a first thread (8) having a variable tooth width, a first sealing surface (9, 7) and a first free end (6) with respect to the second tubular part (3), the second tubular part (3) comprising a second thread (14) having a variable tooth width, a second sealing surface (13, 15) and a second free end (12) with respect to the first tubular part (2), 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 sealing contact in the assembled state of the tubular connection (1), one of the first tubular part (2) and the second tubular part (3) comprising a reference mark (26) having an optimal relative position between the first tubular part (2) and the second tubular part (3), characterized in that the optimal relative position of the reference mark (26) being a corrected optimal relative position (27) corresponding to a nominal optimal relative position to which a correction is applied, the correction depending on a property of the one of the first tubular part (2) and the second tubular part (3) in which the reference mark is arranged and on a target torque of the tubular connection (1).

2. The tubular connection (1) according to claim 1, wherein the correction satisfying the following equation: wherein ST is a tolerance threshold, OD is an outer diameter of the one of the first tubular part (2) and the second tubular part (3) comprising the reference mark (26), Wt is a thickness of the one of the first tubular part (2) and the second tubular part (3) comprising the reference mark (26), CC is the target torque of the tubular connection (1), PdF is a thread pitch of a thread belonging to the one of the first tubular part (2) and the second tubular part (3) comprising the reference mark (26).

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

4. The tubular connection (1) of claim 3, wherein the lower tolerance zone being determined on the one hand by the corrected optimal relative position (27) of the reference mark (26) and on the other hand by a correction lower limit (28), the lower tolerance zone extending from the corrected optimal relative position (27) to the correction lower limit (28) by a corresponding distance in the direction of the free end (6, 12) of the one of the first tubular part (2) and the second tubular part (3) comprising the reference mark (26).

5. The tubular connection (1) of claim 4, wherein, the correction lower limit (28) satisfying the following equation: wherein SI is an interference percentage with respect to sealing, R1 is an acceptable interference loss, ST1 is a slope of the first sealing surface (7, 9), ST2 is a slope of the second sealing surface (13, 15).

6. The tubular connection (1) of claim 5, wherein said correction lower limit being equal to the minimum between a first lower limit and a second lower limit, said first lower limit and second lower limit satisfying the following equations: (1) and (2) if then - the second lower limit = 0, and If then where SI is the sealing-related interference percentage, R1 is the acceptable tolerance loss, ST1 is the inclination of said first sealing surface, ST2 is the inclination of said second sealing surface, and TTdeg is the inclination of one of said first thread (8) and said second thread (14), said one of said first thread (8) and said second thread (14) being arranged on the tubular component comprising said reference mark (26), and Ti is the nominal interference between said first thread and said second thread.

7. The tubular connection (1) according to claim 1, further comprising an upper tolerance zone.

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

9. The tubular connection of claim 8, wherein, said correction upper limit satisfying the following equations: where SI is the sealing-related interference percentage, R2 is the acceptable tolerance loss, ST1 is the inclination of said first sealing surface (7, 9), and ST2 is the inclination of said second sealing surface (13, 15).

10. The tubular connection (1) of claim 9, wherein, said correction upper limit (29) being equal to the minimum between a first upper limit and a second upper limit, said first upper limit and second upper limit satisfying the following equations: (3) (4) if then - the second upper limit = 0, and If then where SI is the sealing-related interference percentage, R2 is the acceptable tolerance loss, ST1 is the inclination of said first sealing surface (7, 9), and ST2 is the inclination of said second sealing surface (13, 15), and TTdeg is the inclination of one of said first thread (8) and said second thread (14), said one of said first thread (8) and said second thread (14) being arranged on the tubular component comprising said reference mark (26), and Ti is the nominal interference between said first thread and said second thread.

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