Threaded connection with spherical-conical seal

Abstract

Threaded tubular connections including a pin member having a male threaded zone having tapered male threads and a box member having a female threaded zone having tapered female threads. The tapered male threads and the tapered female threads have a trapezoidal-shaped thread profile and are configured to engage upon makeup of the threaded tubular connection while a male non-threaded zone and a female non-threaded zone form a spherical-conical metal-to-metal seal. Methods for manufacturing a pin member including threading a radially outward facing surface of a tubular member to produce a male threaded zone having a tapered male thread, where a pin member crown region and a pin member terminal end surface remains non-threaded to produce a male non-threaded zone.

Description

ATTORNEY DOCKET NO. 19078-004W01 THREADED CONNECTION WITH SPHERICAL-CONICAL SEAL BACKGROUND

[0001] Tubular connections are widely used in oilfield operations to join pipes which are used to drill, case, and produce oil and gas. These pipes are commonly known in the industry as Oil Country Tubular Goods (OCTG) and may be threaded and connected in a variety of ways. In general, the type of connection used depends on wellbore conditions, such as depth, temperature, pressure of a well, and performance requirements.

[0002] National pipe thread (NPT) is the standard connection used in running water lines and some casings. NPT uses a single slight thread taper, and the threads tighten and seal to form a connection. Conventional drill pipe connections are called rotary shouldered connections and rely on standardization provided by the American Petroleum Institute (API). In conventional drill pipe connections, the pin end (male end) of a pipe or coupling is threaded into the box end (female end) of another pipe or coupling. The connection between the pin and box ends may have different geometrical features, including thread shape and size. Additionally, the pin and box ends may be formed at the ends of pipe segments to directly connect the pipe segments together in an “integral connection,” or the pin and box ends may be formed at the ends of a pipe segment and a coupling, where the coupling connects pipe segments together in a “threaded and coupled connection.”SUMMARY

[0003] This summary is provided to introduce a selection of concepts that are further described below in the detailed description. This summary is not intended to identify key or essential features of the claimed subject matter, nor is it intended to be used as an aid in limiting the scope of the claimed subject matter.

[0004] In one aspect, embodiments disclosed herein relate to a threaded tubular connection, including a longitudinal axis, a pin member, having a radially outward facing surface having a male non-threaded zone and a male threaded zone including tapered male threads, where a male thread width increases in a first direction along the longitudinal axis, and a box member, having a radially inward facing surface having a female non-threadedATTORNEY DOCKET NO. 19078-004W01zone and a female threaded zone including tapered female threads, where a female thread width decreases in the first direction along the longitudinal axis. In the threaded tubular connection, the tapered male threads and the tapered female threads are configured to engage upon makeup of the threaded tubular connection while the male non-threaded zone and the female non-threaded zone form a spherical-conical metal-to-metal seal and each of the tapered male threads and the tapered female threads have a trapezoidal-shaped thread profile including a crest, a root, a load flank, and a stab flank.

[0005] In another aspect, embodiments disclosed herein relate to a threaded tubular connection, including a longitudinal axis, a pin member having a radially outward facing surface having a male non-threaded zone and a male threaded zone including tapered male threads, and a pin member swaged nose having a swage angle with respect to the longitudinal axis, where a male thread width increases in a first direction along the longitudinal axis; and a box member, including a radially inward facing surface having a female non-threaded zone and a female threaded zone having tapered female threads, where a female thread width decreases in the first direction along the longitudinal axis. In the threaded tubular connection, the tapered male threads and the tapered female threads are configured to engage upon makeup of the threaded tubular connection while the male non-threaded zone and the female non-threaded zone form a spherical-conical metal-to- metal seal, and each of the tapered male threads and the tapered female threads have a trapezoidal-shaped thread profile including a crest, a root, a load flank, and a stab flank.

[0006] In yet another aspect, embodiments disclosed herein relate to a method for manufacturing a pin member, including threading a radially outward facing surface of a tubular member to produce a male threaded zone having a tapered male thread having a male thread width increasing in a second direction along a longitudinal axis and terminating at a male thread end surface, where a pin member crown region having a crown region length defined by the male thread end surface and a pin member terminal end surface remains non-threaded to produce a male non-threaded zone.

[0007] Other aspects and advantages of the claimed subject matter will be apparent from the following description and the appended claims.ATTORNEY DOCKET NO. 19078-004W01 BRIEF DESCRIPTION OF DRAWINGS

[0008] FIG. 1A is a first threaded tubular connection according to one or more embodiments.

[0009] FIG. IB is a disconnected view of the first threaded tubular connection in FIG. 1 A.

[0010] FIG. 2A is a second threaded tubular connection according to one or more embodiments.

[0011] FIG. 2B is a disconnected view of the second threaded tubular connection of FIG.2A.

[0012] FIG. 3 is a visual representation of a method according to one or more embodiments.

[0013] FIG. 4A illustrates a first threaded tubular connection system on two tubular members having an open J-area according to one or more embodiments.

[0014] FIG. 4B illustrates a second threaded tubular connection system on two tubular members having a closed J-area according to one or more embodiments.

[0015] FIG. 4C illustrates a threaded tubular connection on a tubular member having an open J-area according to one or more embodiments.

[0016] FIG. 4D illustrates a threaded tubular connection on a tubular member having a closed J-area according to one or more embodiments.DETAILED DESCRIPTION

[0017] Throughout the application, ordinal numbers (for example, first, second, third) may be used as an adjective for an element (that is, any noun in the application). The use of ordinal numbers is not to imply or create any particular ordering of the elements nor to limit any element to being only a single element unless expressly disclosed, such as using the terms “before,” “after,” “single,” and other such terminology. Rather, the use of ordinal numbers is to distinguish between the elements. By way of an example, a first element isATTORNEY DOCKET NO. 19078-004W01distinct from a second element, and the first element may encompass more than one element and succeed (or precede) the second element in an ordering of elements.

[0018] It is to be understood that the singular forms “a,” “an,” and “the” include plural referents unless the context clearly dictates otherwise. Thus, for example, reference to “a fluid sample” includes reference to one or more of such samples.

[0019] Terms such as “approximately,” “substantially,” etc., mean that the recited characteristic, parameter, or value need not be achieved exactly, but that deviations or variations, including for example, tolerances, measurement error, measurement accuracy limitations and other factors known to those of skill in the art, may occur in amounts that do not preclude the effect the characteristic was intended to provide.

[0020] It is to be understood that one or more of the steps shown in the flowcharts may be omitted, repeated, and / or performed in a different order than the order shown. Accordingly, the scope of the invention should not be considered limited to the specific arrangement of steps shown in the flowcharts.

[0021] Tubular connections must be designed such that they are strong enough to endure loads and combinations of tension, compression, internal pressure, external pressure, and torsion experienced during oilfield operations. Maintaining the integrity of the seal upon makeup of a tubular connection under oilfield conditions is crucial to safety and productivity of a well. Embodiments disclosed herein relate to threaded tubular connections having a tighter seal, a more uniform stress distribution along the connection, the ability to withstand high axial and pressure loads, a deeper stab connection, and lower radial thread interference compared to conventional tubular connections.

[0022] The term “makeup” as used herein refers to the process of rotatedly tightening two threaded components together to form a secure connection. Upon makeup of a threaded connection, a tight seal or secure joint is created between two parts.

[0023] The term “J-area” as used herein refers to a joint area where two threaded components come together. The J-area influences the performance and integrity of the connection. Furthermore, the design of the J-area can affect factors like load distribution,ATTORNEY DOCKET NO. 19078-004W01sealing, and resistance to vibration and fatigue. In some specific applications, such as in pipe fittings or mechanical assemblies, the J-area might be designed to accommodate sealing materials or to ensure proper alignment. In some embodiments, the threaded tubular connections according to one or more embodiments disclosed herein may have an open J-area. In some embodiments, the threaded tubular connections according to one or more embodiments disclosed herein may be made up in a fashion which eliminates (or closes) the J-area.

[0024] The term “pin end” may be interchangeably referred to herein as a “pin member.” Likewise, the term “box end” may be interchangeably referred to herein as a “box or coupling member.”

[0025] Embodiments disclosed herein generally relate to threaded tubular connections having spherical-conical metal-to-metal seals (referred to herein as a spherical-conical seal). Tubular connections disclosed herein may also include a combination of connection features that work together with a spherical-conical seal to provide an improved connection, including a tapered thread having a trapezoidal-shaped thread profile and / or a swaged nose on the pin member.

[0026] Metal-to-metal seals are a type of mechanically energized seal that can be used in pipe connections, such as drill pipe connections. Metal-to-metal seals are generally used in high pressure environments, such as subsea drilling or drilling though deep, high- pressure formations, because metal-to-metal seals provide a tighter and better performing seal than other seal types, such as elastomeric seals. The performance of the metal to metal seal is often enhanced by the pressure loads experienced in-situ. This effect referred to as pressure energization is well known to those skilled in the art. A spherical-conical seal is a type of metal-to-metal seal having an improved geometry compared to conventional frustro-conical metal-to-metal seals. In conventional frustro-conical metal-to-metal seals used with threaded connections, a generally flat portion of a box shoulder contacts a generally flat pin shoulder, which creates a seal upon application of a makeup torque to the connection. In contrast, spherical-conical seals according to one or more embodiments include a metal-to-metal seal between a spherical profile (e.g., curved like a sphere andATTORNEY DOCKET NO. 19078-004W01protruding radially from the connection surface) and a conical surface (e.g., tapered like a cone).

[0027] In one or more embodiments, a spherical-conical seal includes a metal-to-metal seal between a conical surface on the box member base (or shoulder) region and a spherical profile (e.g., curved like a sphere and protruding radially outward) on a pin member crown region. When the box member conical surface contacts the pin member spherical profile, a seal is created along the contact area between the conical and spherical walls, combining the sealing benefits of a sphere with the directional pressure of a cone.

[0028] The interface between the spherical / curved profile of the pin member crown and the conical / planar profile of the box member base allows for the spherical crown surface to roll relative to the planar base surface, thereby maintaining the metal-to-metal seal during movements from external forces being applied to the threaded connection. The spherical-conical seal according to one or more embodiments disclosed herein may advantageously allow for a tighter seal than traditional threads and / or threads with traditional metal-to-metal seal connections. In general, tighter seals advantageously lead to less leakage and better performance, thereby preventing the loss of valuable product during oilfield operations.

[0029] Tapered threads may be used in oilfield connections. A specialty type of tapered thread, known as a wedge or dovetail thread, may have a generally trapezoidal-shaped thread profile, where a thread width increases in opposite directions on the pin member and the box member. Tapered wedge threads may have advantages over simple tapered threads, including creating strong, leak-resistant, and torque-efficient connections due to a helical surface contact area. The tapered threads having trapezoidal-shaped thread profiles according to one or more embodiments may advantageously allow for little or no radial thread interference when threading together the pin member and box member.

[0030] Swaging is the process of shaping an object, typically made of metal, by applying pressure to the object by machine or hammer. The swaging process is generally used to reduce the diameter of, produce a taper on, or add a point to a round object (e.g., a pipe). Swaging a pin member according to embodiments disclosed herein refers to swaging (e.g.,ATTORNEY DOCKET NO. 19078-004W01essentially “pinching”) a nose region of the pin member prior to forming threads on the pin member. Upon swaging a pin member according to embodiments disclosed herein, the pin member nose region’s outer diameter is reduced compared to the outer diameter of a main body thickness of the pin member. Threads may be machined along a radially outward facing surface of the pin member after swaging of the pin nose. The swaged pin nose according to one or more embodiments disclosed herein may advantageously allow for a deeper stab connection. A “deeper stab connection” generally refers to an increased engagement of threads between two tubing sections. Advantages of a deeper stab connection may include improved strength, reduced risk of leakage, and easier makeup.

[0031] In addition, a thickened crown region (e.g., the region on the pin member proximate the pin member terminal surface) according to embodiments disclosed herein may advantageously provide a uniform and higher / stronger stress distribution throughout the connection and improve the ability of the connection to withstand high tensile loads.

[0032] In one aspect, embodiments disclosed herein relate to a first threaded tubular connection 100, as shown in FIG. 1A. The first threaded tubular connection 100 includes a longitudinal axis 106, a threaded zone 116, a non-threaded zone 118, a box member 104, and a first pin member 102. The longitudinal axis 106 extends in a first direction 112 and a second direction 114, which may be used as reference to describe other elements in the corresponding figures.

[0033] The first threaded tubular connection 100 of FIG. 1A includes a made-up connection of threads 122 on the box member 104 and the first pin member 102. The threads 122 will be described further in the following figures, however, as seen in FIG. 1 A, the threads 122 generally include a crest 130, a root 136, a load flank 132 and a stab flank 134. Each thread 122 is a wedge type thread, having a generally trapezoidal-shaped thread profile, where the trapezoidal-shaped thread profile includes a thread height 126 (measured at one-half the length of the crest 130 of the thread) and a thread width 128 (measured at one-half the height of the thread 122 from root 136 to crest 130). In one or more embodiments, on each thread 122 of the first tapered male threads (164 in FIG. IB) andATTORNEY DOCKET NO. 19078-004W01the tapered female threads (158 in FIG. IB), the stab flank 134 is positively inclined, and the load flank 132 is negatively inclined.

[0034] In one or more embodiments, the load flank 132 may have a load flank angle 131 with respect to the longitudinal axis 106. In addition, in one or more embodiments, the stab flank 134 may have a stab flank angle 133 with respect to the longitudinal axis 106. In some embodiments, the load flank angle 131 may be equal to the stab flank angle 133. In some embodiments, the load flank angle 131 may be different from the stab flank angle 133.

[0035] The threads 122 on the box member 104 are generally proximate a box member terminal end surface 110 and the threads 122 on the first pin member 102 are generally proximate a first pin member terminal end surface 108. In addition, the first threaded tubular connection 100 includes a spherical-conical metal -to-metal seal 124 on a nonthreaded portion of the box member 104 and on the first pin member 102. Specifically, a conical surface 162 on a non-threaded portion of the box member 104 and a spherical surface 160 on a non-threaded portion of the first pin member 102 create a spherical-conical metal -to-metal seal 124 upon makeup of the first threaded tubular connection 100.

[0036] FIG. IB shows a first threaded tubular connection separated view 150. As best shown in FIG. IB, the box member 104 includes a radially inward facing surface 154. The radially inward facing surface 154 of the box member 104 may have a female non-threaded zone (e.g., non-threaded zone 118 in FIG. 1 A) and a female threaded zone (e.g., threaded zone 116 in FIG. 1A). The female threaded zone may include tapered female threads 158. In one or more embodiments, a female thread width (e.g., thread width 128 shown in FIG.1A) decreases in a first direction 112 along the longitudinal axis 106.

[0037] The first pin member 102 includes a radially outward facing surface 152. The radially outward facing surface 152 of the first pin member 102 may have a male nonthreaded zone (e.g., non-threaded zone 118 in FIG. 1A) and a male threaded zone (e.g., threaded zone 116 in FIG. 1A). The male threaded zone may include tapered male threads 164. In one or more embodiments, a male thread width (e.g., thread width 128 shown in FIG. 1A) decreases in a second direction 114 along the longitudinal axis 106.ATTORNEY DOCKET NO. 19078-004W01

[0038] The tapered female threads 158 on the box member 104 may have a female thread taper angle 172 with respect to the longitudinal axis 106. Similarly, the tapered male threads 164 on the first pin member 102 may have a male thread taper angle 166 with respect the longitudinal axis 106. In one or more embodiments, the female thread taper angle 172 is equal to the male thread taper angle 166. In one or more embodiments, the female thread taper angle may be in a range of from about 3° to 10°. For example, the female thread taper angle may have a value having a lower limit of from 3°, 4°, and 5° to an upper limit of 6°, 8°, and 10°, where any lower limit may be paired with any upper limit.

[0039] Although the female thread taper angle 172 and the male thread taper angle 166 are shown in FIG. IB as nominal tapers, the wedge shaped threads according to embodiments disclosed herein may have two or more taper angles per member (e.g., box member and pin member). For example, as shown in FIG. 1 A, each thread of the wedge shaped threads 122 includes a stab flank 134 and a load flank 132. The taper of the stab flank and the taper of the load flank may be defined by one or more stab flank taper angle(s) and one or more load flank taper angle(s), respectively. The stab flank taper angle may be generally defined as the angle between the longitudinal axis 106 and a diagonal line connecting a feature on a first stab flank to the same feature on a second, adjacent stab flank, and so on. Similarly, the load flank taper angle may be generally defined as the angle between the longitudinal axis 106 and a diagonal line connecting a feature on a first load flank to the same feature on a second, adjacent load flank, and so on. Additionally, as would be understood by one of ordinary skill in the art, each of the stab flank taper angle(s) and load flank taper angle(s) included on each of the box member and pin member may be adjusted via routine experimentation in order to improve the threaded connection.

[0040] The box member 104 further includes a female non-threaded zone located on a box member base region 176. The box member base region 176 may have a base region length 180 defined by a female thread end surface 178 and a box member shoulder surface 182. In one or more embodiments, the female non-threaded zone includes a conical surface 162 having a planar cross-sectional profile (as best seen in the spherical-conical metal-to-metal seal 124 in FIG. 1A) which may extend across the base region length 180. The conicalATTORNEY DOCKET NO. 19078-004W01surface 162 of the female non-threaded zone may have a cone angle 174 with respect to the longitudinal axis 106.

[0041] In one or more embodiments, the female thread taper angle 172 is greater than the cone angle 174. A female thread taper angle 172 which is greater than the cone angle 174 in the first threaded tubular connection 100 may advantageously allow for amendment and enhancement of the makeup process for the sealing mechanism. As would be understood by one of ordinary skill in the art, the magnitude of the difference between the female thread taper angle 172 and the cone angle 174 will vary by size and thread profile.

[0042] The first pin member 102 further includes a male non-threaded zone located on a first pin member crown region 169. The first pin member crown region 169 has a crown region length 170 defined by a male thread end surface 168 and a first pin member terminal end surface 108. In one or more embodiments, the male non-threaded zone includes a spherical surface 160 having a spherical cross-sectional profile (as best seen in the spherical-conical metal-to-metal seal 124 in FIG. 1A) which may extend across the crown region length 170. In some embodiments, the spherical cross-sectional profile of the spherical surface 160 may extend across a portion of the crown region length 262. The spherical surface 160 of the male non-threaded zone may have a radius of curvature 183. In one or more embodiments, the radius of curvature 183 may be in a range of from about 3° to 10°. For example, the radius of curvature 183 may have a value having a lower limit of from 3°, 4°, and 5° to an upper limit of 6°, 8°, and 10°, where any lower limit may be paired with any upper limit.

[0043] The first pin member crown region 169 may have a first pin member crown region thickness 184 at the first pin member terminal end surface 108. A main body of the first pin member 102 may have a first pin member main body thickness 156. In one or more embodiments, the first pin member crown region thickness 184 is at least one quarter of the first pin member main body thickness 156. In one or more embodiments, there is a discernable relationship between the performance of the seal and the first pin member crown region thickness 184. For example, the thicker the first pin member crown region, the more responsive the seal will be to various loads. However, an upper limit to theATTORNEY DOCKET NO. 19078-004W01thickness may be observed where responsiveness of the seal will be limited due to seal rigidity.

[0044] As described above, the tapered male threads 164 and the tapered female threads 158 are configured to engage upon makeup of the first threaded tubular connection 100 to form threads 122 while the male non-threaded zone and the female non-threaded zone form a spherical-conical metal-to-metal seal 124. Specifically, makeup of the first threaded tubular connection 100 includes a male thread crest (e.g., crest 130 in FIG. 1A) of the tapered male threads contacting a female thread root (e g., root 136 in FIG. 1A) of the tapered female threads. In one or more embodiments, makeup of the first threaded tubular connection 100 also includes a male stab flank (e.g., stab flank 134 in FIG. 1A) contacting a female load flank (e.g., load flank 132 in FIG. 1A). Upon makeup of the first threaded tubular connection 100, a radial thread interference exists between the male thread crest and the female thread root.

[0045] In another aspect, embodiments disclosed herein relate to a second threaded tubular connection. FIG. 2A shows a second threaded tubular connection 200 according to one or more embodiments. The second threaded tubular connection 200 includes a longitudinal axis 106, a threaded zone 116, a non-threaded zone 118, a box member 104, and a second pin member 202. The longitudinal axis 106 extends in a first direction 112 and a second direction 114 and may be used as a reference to describe other elements in the corresponding figures. In one or more embodiments, the box member 104 in the second threaded tubular connection 200 may be the same box member used in the first threaded tubular connection 100. For the sake of brevity, the description of box member 104 will not be repeated in detail herein.

[0046] The second threaded tubular connection 200 of FIG. 2A includes a made-up connection of threads 122 on the box member 104 and the second pin member 202. The threads 122 will be described further in the following figures, however, as seen in FIG. 2 A, the threads 122 generally include a crest 130, a root 136, a load flank 132 and a stab flank 134. Each thread is a wedge type thread, having a generally trapezoidal-shaped thread profile, where the generally trapezoidal-shaped thread profile includes a thread height 126ATTORNEY DOCKET NO. 19078-004W01(measured at one-half the length of the crest 130 of the thread) and a thread width 128 (measured at one-half the height of the thread from root 136 to crest 130. In one or more embodiments, on each thread 122 of the second tapered male threads (266 in FIG. 2B) and the tapered female threads (158 in FIG. 2B), the stab flank 134 is positively inclined, and the load flank 132 is negatively inclined.

[0047] The second threaded tubular connection 200 includes a spherical-conical metal-to- metal seal 124 on a non-threaded portion of the box member 104 and on the second pin member 202. Specifically, a conical surface 162 on a non-threaded portion of the box member 104 and a spherical surface 160 on a non-threaded portion of the second pin member 202 create a spherical-conical metal -to-metal seal 124 upon makeup of the second threaded tubular connection 200.

[0048] FIG. 2B shows a second threaded tubular connection separated view 250. The second pin member 202 includes a radially outward facing surface 152. The radially outward facing surface 152 of the second pin member 202 may have a male non-threaded zone (e.g., non-threaded zone 118 in FIG. 2A) and a male threaded zone (e.g., threaded zone 116 in FIG. 2A). The male threaded zone may include second tapered male threads 266 having a second male thread taper angle 258 with respect to the longitudinal axis 106. In one or more embodiments, a male thread width (e.g., thread width 128 shown in FIG.2A) decreases in a second direction 114 along the longitudinal axis 106. In one or more embodiments, the second pin member 202 may have a swaged nose 204 having a swage angle 272 with respect to the longitudinal axis 106.

[0049] The second pin member 202 further includes a male non-threaded zone located on a second pin member crown region 271. The second pin member crown region 271 has a crown region length 262 defined by a male thread end surface 168 and a second pin member terminal end surface 206. In one or more embodiments, the male non-threaded zone includes a spherical surface 160 having a spherical cross-sectional profile (as best seen in the spherical-conical metal -to-metal seal 124 in FIG. 2A) which may extend across the crown region length 262. In some embodiments, the spherical cross-sectional profile of the spherical surface 160 may extend across a portion of the crown region length 262. TheATTORNEY DOCKET NO. 19078-004W01spherical surface 160 of the male non-threaded zone may have a radius of curvature 270. In one or more embodiments, the radius of curvature 270 may be in a range of from about 3° to 10°. For example, the radius of curvature 270 may have a value having a lower limit of from 3°, 4°, and 5° to an upper limit of 6°, 8°, and 10°, where any lower limit may be paired with any upper limit.

[0050] The second pin member crown region 271 may have a second pin member crown region thickness 268 at the second pin member terminal end surface 206. A main body of the second pin member 202 may have a second pin member main body thickness 252. In one or more embodiments, the second pin member crown region thickness 268 is at least one quarter of the second pin member main body thickness 252. In one or more embodiments, there is a discernable relationship between the performance of the seal and the second pin member crown region thickness 268.

[0051] The second tapered male threads 266 and the tapered female threads 158 are configured to engage upon makeup of the second threaded tubular connection 200 to form threads 122 while the male non-threaded zone and the female non-threaded zone form a spherical-conical metal-to-metal seal 124. Specifically, makeup of the second threaded tubular connection 200 includes a conical surface 162 of the female non-threaded zone contacting a spherical surface 160 on the male non-threaded zone. In one or more embodiments, makeup of the second threaded tubular connection 200 further includes a male thread crest (e.g., crest 130 in FIG. 2A) of the tapered male threads contacting a female thread root (e.g., root 136 in FIG. 2A) of the tapered female threads. In one or more embodiments, makeup of the second threaded tubular connection 200 also includes a male stab flank (e.g., stab flank 134 in FIG. 2A) contacting a female load flank (e.g., load flank 132 in FIG. 2A). Upon makeup of the second threaded tubular connection 200, a radial thread interference exists between the male thread crest and the female thread root. In one or more embodiments, the radial thread interference of the second threaded tubular connection 200 may advantageously be higher than the radial thread interference of the first threaded tubular connection.ATTORNEY DOCKET NO. 19078-004W01

[0052] Embodiments disclosed herein also relate to a method for manufacturing a pin member. A visual representation of the method 300 is shown FIG. 3. As shown with reference to FIG. 3, the method may include providing a tubular member 302 to a swaging process 306. In one or more embodiments, the tubular member 302 has a longitudinal axis 106 extending in a first direction 112 and a second direction 114.

[0053] The tubular member 302 of one or more embodiments may be any suitable tubular known in the art. A tubular member generally refers to a hollow, cylindrical structural component. In the art, tubing may refer to drill pipe, casing, tubing, coiled tubing, and the like.

[0054] The swaging process 306 of one or more embodiments may be any suitable process capable of swaging a tubular member 302 as described herein. The swaging process may include a swaging machine or the like. The swaging machine may include a die selected to correspond to the desired final shape of the tubular member. The swaging process may include several steps including but not limited to loading the tubular member in the swaging machine and aligning it with the die and deforming the tubular member using a ram to force the metal into a die cavity.

[0055] Returning to FIG. 3, the method further includes swaging a portion of the tubular member 302 proximate a second pin member terminal end surface 206 to produce swaged tubular member 308 comprising a pin member swaged nose 204 having a swage angle 218 with respect to the longitudinal axis 106. In one or more embodiments, the method further includes threading 312 a radially outward facing surface 152 of the swaged tubular member 308 to produce a male threaded zone comprising second tapered male threads 266. The second tapered male threads 266 may have a tapered male thread width which increases in the first direction 112 along the longitudinal axis 106. In one or more embodiments, the second tapered male threads 266 may terminate at a male thread end surface 168. A second pin member crown region 271 proximate the second pin member terminal end surface 206 may include a crown region length 262 defined by the male thread end surface 168 and the second pin member terminal end surface 206. In one or more embodiments, the second pin member crown region 271 remains non-threaded to produce a male non-threaded zone.ATTORNEY DOCKET NO. 19078-004W01

[0056] The threading process of one or more embodiments may be any suitable threading process capable of producing second tapered male threads 266 as disclosed herein. The threading process may include manual threading or automatic threading. Threads may be created using a pipe threading machine or manual threading tools.

[0057] In one or more embodiments, the method may further include forming the second pin member crown region 271 to produce a spherical surface 160 having a spherical cross- sectional profile extending across the crown region length 262. The spherical surface 160 may include a radius of curvature. Upon forming the second pin member crown region 271, a second pin member 202 is produced.

[0058] Forming the pin member of one or more embodiments may refer to any suitable process capable of producing a spherical surface 160 as disclosed herein. Forming the pin member may also be referred to as “tube end forming” or “tube end rounding.” The forming process may include hammering by using mechanical or manual hammers, die forming, roll forming, or deburring. In some embodiments, the pin member may be formed by machining with a computer numerical control (CNC) machine.

[0059] FIG. 4A illustrates a first threaded tubular connection system 400 joining two tubular members having an open J-area according to one or more embodiments. As shown in FIG. 4A, the first threaded tubular connection system 400 may include a first tubular member 402 and a second tubular member 404. The first tubular member 402 and the second tubular member 404 may be joined together by a threaded tubular connection (e.g., a first threaded tubular connection 100 or a second threaded tubular connection 200). In the first threaded tubular connection system 400, a first tubular member terminal end surface 406 and a second tubular member terminal end surface 408 may be axially separated by a distance referred to as a J-area 407.

[0060] FIG. 4B illustrates a second threaded tubular connection system 420 joining two tubular members having a closed J-area according to one or more embodiments. As shown in FIG. 4B, the second threaded tubular connection system 420 may include a first tubular member 402 and a second tubular member 404. The first tubular member 402 and the second tubular member 404 may be joined together by a threaded tubular connection (e.g.,ATTORNEY DOCKET NO. 19078-004W01a first threaded tubular connection 100 or a second threaded tubular connection 200). In the second threaded tubular connection system 420, a first tubular member terminal end surface 406 and a second tubular member terminal end surface 408 may abut one another to eliminate the J-area 407, producing an abutted pin nose 422.

[0061] FIG. 4C illustrates a threaded tubular connection system 440 on a tubular member having an open J-area according to one or more embodiments. In FIG. 4C, a threaded tubular connection (e.g., a first threaded tubular connection 100 or a second threaded tubular connection 200) may be made up on a first tubular member 402 and a second tubular member 404. The axial length traversed by the box member 104 upon the pin member (e.g., a first pin member 102 and a second pin member 202) is referred to as a coupling length 442. The first tubular member 402 may have a first tubular member terminal end surface 406 and the second tubular member 404 may have a second tubular member terminal end surface 408. The axial length traversed by a portion of the box member 104 from a box member first terminal end surface (e.g., box member terminal end surface 110) to the first tubular member terminal end surface 406 is referred to as a makeup loss 444 length. Similarly, the axial length traversed by a portion of the box member 104 from a box member second terminal end surface 446 to the second tubular member terminal end surface 408 is also referred to as a makeup loss 444 length, where the box member first terminal end surface is axially opposite the box member second terminal end surface 446. As shown in FIG. 4C, the first tubular member terminal end surface 406 and the second tubular member terminal end surface 408 may be axially separated by a distance referred to as a J-area 407. The J-area 407 may also be defined by an axial length equal to a difference between the coupling length 442 and the combined length of makeup loss 444 regions.

[0062] FIG. 4D illustrates a threaded tubular connection system 460 on a tubular member having a closed J-area according to one or more embodiments. In FIG. 4D, a threaded tubular connection (e.g., a first threaded tubular connection 100 or a second threaded tubular connection 200) may be made up on a first tubular member 402 and a second tubular member 404. The axial length traversed by the box member 104 upon the pin member (e.g., a first pin member 102 and a second pin member 202) is referred to as aATTORNEY DOCKET NO. 19078-004W01coupling length 442. The first tubular member 402 may have a first tubular member terminal end surface 406 and the second tubular member 404 may have a second tubular member terminal end surface 408. As shown in FIG. 4D, the first tubular member terminal end surface 406 and the second tubular member terminal end surface 408 may abut one another to eliminate the J-area 407, producing an abutted pin nose422. In one or more embodiments, eliminating the J-area 407 may be accomplished using a protrusion on one or more of the first tubular member terminal end surface 406 and the second tubular member terminal end surface 408 or by using a recess free bore.

[0063] Although only a few example embodiments have been described in detail above, those skilled in the art will readily appreciate that many modifications are possible in the example embodiments without materially departing from this invention. Accordingly, all such modifications are intended to be included within the scope of this disclosure as defined in the following claims.

Claims

ATTORNEY DOCKET NO. 19078-004W01CLAIMSWhat is claimed:

1. A threaded tubular connection, comprising:a longitudinal axis;a pin member, comprising,a radially outward facing surface having a male non-threaded zone and a male threaded zone comprising tapered male threads,wherein a male thread width increases in a first direction along the longitudinal axis; anda box member, comprising,a radially inward facing surface having a female non-threaded zone and a female threaded zone comprising tapered female threads, and wherein a female thread width decreases in the first direction along the longitudinal axis;wherein the tapered male threads and the tapered female threads are configured to engage upon makeup of the threaded tubular connection while the male non-threaded zone and the female non-threaded zone form a spherical-conical metal-to-metal seal, wherein each of the tapered male threads and the tapered female threads have a trapezoidalshaped thread profile comprising a crest, a root, a load flank, and a stab flank.

2. The threaded tubular connection of claim 1, wherein the tapered female threads comprise a female thread taper angle with respect to the longitudinal axis, and the tapered male threads comprise a male thread taper angle with respect the longitudinal axis, and wherein the female thread taper angle is equal to the male thread taper angle.

3. The threaded tubular connection of claim 2, wherein the female non-threaded zone is located on a box member base region, the box member base region having a base region length defined by a female thread end surface and a box member shoulder surface, and wherein the female non-threaded zone comprises a conical surface having a planar cross-ATTORNEY DOCKET NO. 19078-004W01sectional profile and extending across the base region length, the conical surface comprising a cone angle with respect to the longitudinal axis.

4. The threaded tubular connection of claim 3, wherein the female thread taper angle is greater than the cone angle.

5. The threaded tubular connection of claim 1, wherein the male non-threaded zone is located on a pin member crown region, the pin member crown region having a crown region length defined by a male thread end surface and a pin member terminal end surface, and wherein the male non-threaded zone comprises a spherical surface having a spherical cross- sectional profile and extending across the crown region length, the spherical surface comprising a radius of curvature.

6. The threaded tubular connection of claim 5, wherein the pin member crown region comprises a crown region thickness at the pin member terminal end surface, wherein the crown region thickness is at least one quarter of a pin member main body thickness.

7. The threaded tubular connection of claim 1, wherein makeup of the threaded tubular connection further comprises a conical surface of the female non-threaded zone contacting a spherical surface on the male non-threaded zone, a male thread crest of the tapered male threads contacting a female thread root of the tapered female threads, wherein a radial thread interference exists between the male thread crest and the female thread root, and a male stab flank of the tapered male threads contacting a female load flank of the tapered female threads.

8. The threaded tubular connection of claim 1, wherein on each thread of the tapered male threads and the tapered female threads, the stab flank is positively inclined, and the load flank is negatively inclined.

9. The threaded tubular connection of claim 1, wherein the stab flank comprises a stab flank taper angle and the load flank comprises a load flank taper angle.ATTORNEY DOCKET NO. 19078-004W0110. A threaded tubular connection, comprising:a longitudinal axis;a pin member, comprising,a radially outward facing surface having a male non-threaded zone and a male threaded zone comprising tapered male threads, anda pin member swaged nose having a swage angle with respect to the longitudinal axis,wherein a male thread width increases in a first direction along the longitudinal axis; anda box member, comprising,a radially inward facing surface having a female non-threaded zone and a female threaded zone comprising tapered female threads, andwherein a female thread width decreases in the first direction along the longitudinal axis;wherein the tapered male threads and the tapered female threads are configured to engage upon makeup of the threaded tubular connection while the male non-threaded zone and the female non-threaded zone form a spherical-conical metal-to-metal seal, wherein each of the tapered male threads and the tapered female threads have a trapezoidalshaped thread profile comprising a crest, a root, a load flank, and a stab flank.

11. The threaded tubular connection of claim 10, wherein the female non-threaded zone is located on a box member base region, the box member base region having a base region length defined by a female thread end surface and a box member terminal end surface, and wherein the female non-threaded zone comprises a conical surface having a planar cross- sectional profile and extending across the base region length, the conical surface comprising a cone angle with respect to the longitudinal axis.

12. The threaded tubular connection of claim 11, wherein the tapered female threads comprise a female thread taper angle with respect the longitudinal axis and wherein the female thread taper angle is greater than the cone angle.ATTORNEY DOCKET NO. 19078-004W0113. The threaded tubular connection of claim 10, wherein the male non-threaded zone is located on a pin member crown region, the pin member crown region having a crown region length defined by a male thread end surface and a pin member terminal end surface, and wherein the male non-threaded zone comprises a spherical surface having a spherical cross-sectional profile and extending across the crown region length, the spherical surface comprising a radius of curvature.

14. The threaded tubular connection of claim 13, wherein the pin member crown region comprises a crown region thickness at the pin member terminal end surface, wherein the crown region thickness is at least one quarter of a pin member main body thickness.

15. The threaded tubular connection of claim 10, wherein makeup of the threaded tubular connection further comprises a conical surface of the female non-threaded zone contacting a spherical surface on the male non-threaded zone, a male thread crest of the tapered male threads contacting a female thread root of the tapered female threads, wherein a radial thread interference exists between the male thread crest and the female thread root, and a male stab flank of the tapered male threads contacting a female load flank of the tapered female threads.

16. The threaded tubular connection of claim 10, wherein on each thread of the tapered male threads and the tapered female threads, the stab flank is positively inclined, and the load flank is negatively inclined.

17. The threaded tubular connection of claim 10, wherein the stab flank comprises a stab flank taper angle and the load flank comprises a load flank taper angle.

18. A method for manufacturing a pin member, comprising:threading a radially outward facing surface of a tubular member to produce a male threaded zone comprising a tapered male thread having a male thread width increasing in a second direction along a longitudinal axis and terminating at a male thread end surface, wherein a pin member crown region having a crown region length defined by the male thread end surface and a pin member terminal end surface remains nonthreaded to produce a male non-threaded zone.ATTORNEY DOCKET NO. 19078-004W0119. The method of claim 18, further comprising forming the pin member crown region to produce a spherical surface having a spherical cross-sectional profile extending across the crown region length, the spherical surface comprising a radius of curvature.

20. The method of claim 19, further comprising:providing the tubular member to a swaging process; andswaging a portion of the tubular member proximate the pin member terminal end surface to produce a swaged tubular member comprising a pin member swaged nose having a swage angle with respect to the longitudinal axis.

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