WO2012047562A2

WO2012047562A2 - Welded downhole components and method of forming same

Info

Publication number: WO2012047562A2
Application number: PCT/US2011/053095
Authority: WO
Inventors: Joel Franklin Hugghins
Original assignee: National Oilwell Varco, L.P.
Priority date: 2010-09-28
Filing date: 2011-09-23
Publication date: 2012-04-12
Also published as: MX2013003442A; US20130180728A1; WO2012047562A3

Abstract

Welded downhole tools and methods are provided. The downhole tool is deployable into a wellbore penetrating a subterranean formation. The downhole tool includes a first downhole component having a first mating feature on at least one end thereof and at least one second downhole component weldably connectable to the end of the first downhole component. The second downhole component has a second mating feature on an end thereof. The first and second mating features include at least one raised ridge for concentric self-alignment along a common axis with the other of the first and second mating features whereby, upon frictional engagement of the end of the first downhole component with the end of the second component under heat and pressure, a welded connection is formed therebetween.

Description

WELDED DOWNHOLE COMPONENTS AND METHOD OF FORMING SAME

BACKGROUND

1. Field

The present disclosure relates generally to downhole components used with oil rigs. Specifically, the invention relates to welding downhole components involving, for example, the alignment of mating features to facilitate friction welding,

2. Background of the Related Art

Friction welding is a technique where two independent components are fused together using pressure and heat produced through friction. One component may be chucked and rotated, often at high speed, and pressed into another typically stationary component. The chucked component may also be oscillated side to side. The zone (sometimes referred to as a weld zone) in which the two components make contact may heat rapidly and eventually melt, thereby fusing the two components into one indistinguishable and integral part. Excess material or flash material may be produced at the weld zone and radiated outward. This material may also radiate inward, for example in the case of hollow parts, as the liquefied material from the two components is displaced during welding.

Friction welding is commonly used to join downhole components, such as a base pipe with tool joints to form a drill pipe. Tool joints are typically threaded end connections that connect one drill pipe to another drill pipe or drilling tools. When joining the base pipe and tool joints, the base pipe may be clamped or restrained to remain stationary. The tool joints may be chucked to rotate while its end connection is pressed into the base pipe until both components are friction welded together.

Various tolerances, such as centerline concentricity and angular deviation tolerances (also known as offset and angularity tolerances respectively), may be specified by the drill pipe industry. These tolerances may require specialized measuring equipment. Several apparatuses have been designed over the years in an attempt to center the stationary component (e.g., the base pipe) along the chuck's centerline to mitigate misalignment beyond the specified tolerances. Such apparatuses may be costly and the components may be needed in order to be friction welded within the specified tolerances. It may be desirable to have repeatable techniques for providing welding drill pipes within specified tolerances, preferably without requiring such specialized apparatuses.

SUMMARY

Disclosed herein is a method and apparatus for using concentric mating features to self- align two components along a common axis to be friction welded together. In at least one aspect, the disclosure relates to a downhole tool deployable into a wellbore penetrating a subterranean formation. The downhole tool includes a first downhole component having a first mating feature on at least one end thereof and at least one second downhole component having a second mating feature on an end thereof weldably connectable to the end of the first downhole component. At least one of the first and second mating features includes at least one raised ridge for concentric self-alignment along a common axis with the other of the first and second mating features whereby, upon frictional engagement of the end of the first downhole component with the end of the second component under heat and pressure, a welded connection is formed therebetween.

At least one of the first and second mating features may include at least one channel for receiving the at least one raised ridge. The first downhole component may include a base pipe and the second downhole component may include a pair of tool joints weldable to each end of the base pipe to form a drill pipe. The first and second downhole components may be a pipe or a bar. The first and second components may be concentric or non-concentric along the common axis. The first downhole component may have the same outer diameter as the at least one second downhole component.

The first downhole component may have a different outer diameter from the second downhole component. The ridge and the channel may be conical, rounded, and/or beveled. The first and second mating features may be complimentary or non-complimentary. The end of the first downhole component and the end of the second downhole component each may have a seating surface. The seating surface may be perpendicular to a longitudinal axis of the first and second downhole components. The first downhole component may be recessable a distance into the at least one second downhole component. The second downhole component may have a flange recessed a distance therein for receiving the first downhole component.

The downhole tool may include a third downhole component positionable between the first and second downhole components. The third downhole component may be a ferrel, a sleeve, a disc, and/or a mandrel. Each of the first and second components may be hollow and/or solid.

In another aspect, the disclosure may relate to a downhole tool deployable into a wellbore penetrating a subterranean formation. The downhole tool includes a first downhole component having a first mating feature on at least one end thereof, at least one second downhole component having a second mating feature on an end thereof weldably connectable to the first downhole component, and a third downhole component positionable between the first and second downhole components for concentric alignment therebetween along a common axis whereby, upon frictional engagement of the end of the first downhole component with the end of the second component under heat and pressure, a welded connection is formed therebetween. The third downhole component may be removable or consumed during welding.

Finally in another aspect, the disclosure relates to a method for welding a downhole tool deployable into a wellbore penetrating a subterranean formation. The method involves providing a first downhole component having a first mating feature on at least one end thereof and at least one second downhole component having a second mating feature on an end thereof weldably connectable to the end of the first downhole component (the first and second mating features including at least one raised ridge), concentrically self-aligning along a common axis the first and second mating features, and forming a welded connection between the first downhole component and the second downhole component by frictionally engaging the end of the first downhole component with the end of the second component under heat and pressure.

The method forming may involve rotating the first component and/or maintaining the second component in a stationary position. The matingly engaging may involve interfitting the first mating feature with the second mating feature, self-aligning the first mating feature with the second mating feature. The method may further involve inserting at least one additional component between the first downhole component and the second downhole component, consuming the additional component in the forming of a welded connection. The forming may involve one of friction welding, fusing and combinations thereof. The first and second downhole components may be fused together according to concentricity and angularity tolerances.

BRIEF DESCRIPTION OF THE DRAWINGS

Figure 1 is a schematic view, partially in cross-section of an oil rig with a drill string deployed therefrom and advanced into the earth to form a wellbore, the drill string including a plurality of drill pipe with welded tool joints.

Figures 2 - 11 are schematic views of various welded connections between downhole components.

Figure 12 is a perspective view of an alternate welded connection between a rotating downhole component and a stationary downhole component.

Figures 13 - 18 are schematic views of various additional welded connections between downhole components.

Figure 19 is a flow chart depicting a method of welding downhole components.

DETAILED DESCRIPTION

The techniques herein relate to welded downhole components, such as drill pipe used in downhole drilling. The drill pipe may have a base pipe with a tool joint at each end welded thereto. The base pipe and tool joints may have concentric mating features to self-align the base pipe with the tool joints along a common axis to be friction welded together. Many of the downhole components in the drilling industry may be cylindrical and substantially symmetrical about an axis. These components may be placed in a wellbore that is substantially circular and has a diameter. This wellbore is typically vertical, but may also include oblique or horizontal portions. Downhole components including, but not limited to, drill pipe, casing, coiled tubing, stabilizers, centralizers, mud motors, and downhole tools, are attached end to end. These downhole components may be part or all of a downhole tool or combinations of downhole tools, such as base pipe and tool joints of a drill pipe. When the downhole components are attached end to end, it may be desirable for each component to be aligned along a common axis. This common axis may be defined as the axis of rotation of the downhole components. This common axis may be the same as a centerline of a wellbore.

Offset and angularity may be explicitly specified in the drill pipe industry. The drilling industry may desire small offsets and/or angularity tolerances for many reasons, including, but not excluded to, reduced wear on the downhole components, ease of storing components, and predictable stresses within the downhole components. Connected drill pipe sections that are concentric about a common axis and within specified angularity tolerances may also reduce friction, increase drilling performance, and increase drilling efficiency compared with drill pipe that has offset or angularity outside specified tolerances. Concentric drill pipe may also improve flow through the drill pipe and enable larger components to trip through the drill pipe. Outside the drilling industry, concentric features may behave optimally and predictably under stress, provide for improved seals, and provide numerous practical benefits.

Figure 1 depicts a wellsite 1 having a rig 2 with a drill string 3 deployed therefrom and into a wellbore 4. The drill string 3 includes multiple drill pipes 5 threaded together end to end, and a downhole tool 6 with a drill bit 7 at a downhole end thereof. Each drill pipe 5 has a base pipe 20 (or middle section) with threaded tool joints 10 on each end. These threaded tool joints 10 may enable each drill pipe 5 to be connected to other drill pipe 5 or downhole tools.

Tool joints 10 may be manufactured separately from the base pipe 20 , and typically have a threaded end 8 and a flat connection end 9. The tool joints 10 may have a male connection with external threads or a female connection with internal threads for threaded engagement therebetween as indicated by the dashed lines. The connection end 9 of the tool joint 10 may have substantially the same outer diameter, thickness, and inner diameter of the base pipe 20. The tool joint 10 may have a joint face 15 on an end thereof.

Drill pipe may be created by welding, friction welding, fusing, or otherwise joining tool joints 10 to each end of the base pipe 20 to form the continuous drill pipe 5 with threaded tool joints 10 on both ends. Tool joints 10 and base pipe 20 may be fused together to form a welded connection 17 such that the completed drill pipe 5 is within specified concentricity and angularity tolerances may provide, for example, reduced friction downhole, increased drilling performance, increased drilling efficiency, improved flow through the drill pipe 5, and larger passage through the drill pipe 5.

The base pipe 20 has two pipe faces 25, one on each end. A first pipe face 25 may fuse with the tool joint 10 having a male connection and a second pipe face 25 may fuse with the tool joint 10 having a female connection. Alternatively, the base pipe 20 may have the tool joint 10 with a female connection fused to each pipe face 25, or the base pipe 20 may have a tool joint 10 with a male connection fused to each pipe face 25.

The pipe face 25 and the joint face 15 are collectively mating faces that may have a mating means (or features). Other mating faces that may have a mating means include but are not limited to tubular ends, and ends of solid members with a circular cross section, or solid or hollow flanges with a circular cross section. When joined together, one mating face is received into a portion of the other mating face. The mating means includes, but is not limited to, a raised lip and a depressed ledge, a tapered inner diameter and a tapered outer diameter, a ridge (and/or projection) and a channel, and combinations thereof. The mating means may also include one mating face with at least one positive feature or shape and the other mating face with at least one negative feature or shape that is generally the inverse of the at least one positive feature or shape. The dimensions of the at least one positive feature or shape need not be identical to the dimensions of the at least one negative feature or shape. Furthermore, the mating means may include a first mating face with both positive and negative features or shapes and a second mating face with both positive and negative features or shapes that are generally the inverse of the first mating face. These mating features may include both helical and radial attributes, such as threading, grooves, and channels to control flash flow direction or enhance alignment.

Additionally, the mating means may include a first mating face with a first set of features and second mating face with a dissimilar set of features, in an embodiment, the mating faces may be substantially complementary and cause concentric self-alignment of the mating faces and components when pressed together. In another embodiment, the mating faces may not be complementary, but still cause concentric self-alignment of the mating faces and components when pressed together. Furthermore, the first component with the first mating face and the second component with the second mating face need not have similar geometries including, but not limited to, different inner diameter, different outer diameter, different, thickness, and combinations thereof. The diameters of the first mating face and the second mating face may range from 0.01 inches (.00254 cm) to about 25 feet (7.62 m). The first component and the second component need not be of the same material. The thickness of the first and/or second component may range from about 0.01 inches (0.0254 cm) to a solid component. Both the first component and second component may be hollow, solid, or combinations thereof.

The mating means may include features or shapes that are generally equidistant from the centerline of the component such that when joined together, the components self-align along the common axis. When the components are concentrically self-aligned, the centerline of one component may coincide with the centerline of the other component. The coinciding centerlines may form a common axis of the components when joined or fused together. Thus, the mating means may be concentric about the common axis.

The mating faces may include a plurality of negative features, such as depressed ledges, channels, and inverse tapers. Either mating face may contain additional negative features that do not mate with a feature on the opposing mating face. These non-mating negative features of either mating face may be concentric with the mating features of the mating faces, may be eccentric with the mating features of the mating faces, may be a chord or radius across the first mating face, or may have another shape that does not negatively affect the concentric alignment of the mating faces when pressed together. Radial and concentric features may also be employed to control and/or direct the flow of the flash as produced during the welding process.

The mating faces may also include a plurality of positive features such as raised ledges, ridges, tongues, trapezoids, beads, tapers, etc. Either mating face may contain additional positive features that do not mate with a feature on the opposing mating face. These non-mating positive features of either mating face may be concentric with the mating features of the mating faces, may be eccentric with the mating features of the mating faces, may be a chord or radius across the first mating face, or may have another shape that does not negatively affect the concentric alignment of the mating faces when pressed together.

Figure 2 illustrates a cross section of an embodiment of the tool joint 10 with a depressed ledge 13 and the base pipe 20 with a raised lip 23. The depressed ledge 13 and the raised lip 23 may be beveled. This embodiment illustrates a concentric mating means for aligning the tool joint 10 and the base pipe 20 by the beveled raised lip 23 and the beveled depressed ledge 13. The tool joint 10 has the connection end 9 and the threaded end 8, a tool centerline 11, an inner diameter 12, the depressed ledge 13, a joint thickness 14, the joint face 15, and an outer diameter 16. The base pipe 20 has a pipe centerline 21, an inner diameter 22, the raised lip 23, a pipe thickness 24, the pipe face 25, and an outer diameter 26. In order to form a drill pipe 5, the connection end 9 of the tool joint 10 may be welded to the base pipe 20.

The mating features in this embodiment are the depressed ledge 13 on the inner diameter 12 of the tool joint 10 and the raised lip 23 on the inner diameter 22 of the base pipe 20. The raised lip 23 is a positive (or male) feature that is elevated beyond the pipe face 25. The depressed ledge 13 is a negative (or female) feature of the tool joint 10 that is depressed below the joint face 15 and is the inverse of the raised lip 23. Both the raised lip 23 and the depressed ledge 13 are equidistant from the centerlines 11 and 21 respectively. When pressed together, the tool joint 10 and the base pipe 20 mate so that the raised lip 23 interfaces with the depressed ledge 13, the pipe face 25 interfaces with joint face 15, and the tool centerline 11 coincides with the pipe centerline 21. The depressed ledge 13 and raised lip 23 are positioned such that the joint face 15 will not interface with the pipe face 25 unless the tool centerline 11 coincides with the pipe centerline 21, thus making the tool joint 10 concentric with the base pipe 20. This arrangement may be characterized as a 'bevel against flat' weld configuration.

The depressed ledge 13 and mating raised lip 23 may be on the inner diameter (ID) 12 and 22 of the tool joint 10 and base pipe 20, respectively, as illustrated in Figure 2, or on the outer diameter (OD) 16 and 26 of the tool joint 10 and base pipe 20, respectively. Alternatively, in a 'radiused against beveled' weld configuration, as illustrated in Figure 7, a tool joint 50 may have a raised lip 51 on or near an OD 54 of the tool joint 50 and a depressed ledge 52 on or near an ID 53 of the tool joint 50, and the base pipe 55 may have a depressed ledge 56 on or near an OD 59 of the base pipe 55 and a raised lip 57 on or near an ID 58 of the base pipe 55.

Furthermore, the tool joint 50 may have a depressed ledge on the ID 53 or OD 54, a raised lip on the ID 53 or OD 54, or any combination thereof and the base pipe 55 may have a depressed ledge on the ID 58 or OD 59, a raised lip on the ID 58 or OD 59, or any combination thereof such that when pressed together, the components self-align and the tool centerline 11 coincides with the pipe centerline 21. Referring back to Figure 2, the raised lip 23 and depressed ledge 13 may be of any width less than the thickness 24 and 14 that permits concentric self- alignment of the base pipe 20 and tool joint 10. The cross section of the raised lip 23 may be any shape including, but not limited to, a rectangle, trapezoid, triangle, or arc. The depressed ledge 13 may be any shape, optionally complementary, that permits concentric self-alignment such that the tool centerline 11 and the pipe centerline 21 coincide when the tool joint 10 and base pipe 20 are pressed together.

Additionally, the depressed ledge 13 may be depressed further from the joint face 15 than the raised lip 23 is elevated beyond the pipe face 25. The lip and ledge features may be on the tool joint 10 and base pipe 20 in any combination such that a lip corresponds with a ledge on the opposing surface so that the components may concentrically self-align when pressed together.

As illustrated in Figure 2, the raised lip 23 and depressed ledge 13 may be beveled. This beveling may aid self-alignment and increase the interface surface area. The bevel may range from about 1° to about 90°. Furthermore, the bevel of the raised lip 23 need not be the inverse of the bevel of the depressed ledge 13. The bevel of the raised lip 23 may be a different angle than the bevel of the depressed ledge 13.

Figure 3 illustrates a cross section of an embodiment of a tool joint 30 with a ridge 33 and a base pipe 40 with a channel 43 in a truncated tongue and groove weld configuration. The tool joint 30 has a tool centerline 31, an inner diameter 32, the ridge 33, a joint thickness 34, a joint face 35, and an outer diameter 36. The base pipe 40 has a pipe centerline 41, an inner diameter 42, the channel 43, a pipe thickness 44, a pipe face 45, and an outer diameter 46. This embodiment illustrates a concentric mating means for aligning the tool joint 30 and the base pipe 40 by the beveled ridge 33 and the beveled channel 43.

The mating features in this embodiment are the ridge 33 between the inner diameter 32 and outer diameter 36 of the tool joint 30 and the channel 43 between the inner diameter 42 and outer diameter 46 of the base pipe 40. The ridge 33 is a positive feature that is elevated beyond the joint face 35. The channel 43 is a negative feature of the base pipe 40 that is depressed below the pipe face 45 and may be the inverse of the ridge 33. The ridge 33 and the channel 43 are complimentary for mating engagement therebetween. Both the ridge 33 and the channel 43 are equidistant from the centerlines 31 and 41, respectively. When pressed together, the tool joint 30 and the base pipe 40 mate so that the ridge 33 interfaces with the channel 43, the joint face 35 interfaces with the pipe face 45, and the tool centerline 31 coincides with the pipe centerline 41. The ridge 33 and channel 43 are positioned such that the joint face 35 will not interface with the pipe face 45 unless the tool centerline 31 coincides with the pipe centerline 41, thus making the tool joint 30 concentric with the base pipe 40.

As shown in Figure 3, the ridge 33 and channel 43 are on the joint thickness 34 and pipe thickness 44 respectively. Alternatively, the base pipe 40 may have a ridge and the tool joint 30 has a corresponding channel (not shown). Furthermore, as illustrated in Figure 6, a mating face 75 of a first tool joint (or component) 70 and a mating face 85 of a second base pipe (or component) 80 may have any combination of one or more ridges, such as middle ridge 73, and at least as many channels, such as middle channel 83, as ridges 73 such that each ridge mates with the corresponding channel 83 on the opposing surface to cause concentric self-alignment of the components when pressed together. Each mating ridge 73 and channel 83 on either the first mating face 75 or the second mating face 85 is equidistant at all points from a centerline 79 of the respective component so that the components self-align to be concentric to a common axis. This embodiment illustrates a concentric mating means for aligning first component and a second component by a taper and inverse taper towards the outer diameter in combination with a plurality of concentric ridges and channels.

Referring back to Figure 3, the ridge 33 and channel 43 may be of any width less than the thicknesses 34 and 44 that permits concentric self- alignment of the toot joint 30 and base pipe 40. The cross section of the ridge 33 may be any shape including but not limited to a rectangle, trapezoid, triangle, parabola, or semicircle. The channel 43 may be any shape that permits concentric self-alignment such that the tool centerline 31 and the pipe centerline 41 coincide when the tool joint 30 and base pipe 40 are pressed together. Additionally, the channel 43 may be depressed further from the pipe face 45 than the ridge 33 is elevated beyond the joint face 35. As illustrated in Figure 9, a semicircular ridge 91 projects from a joint face 92 of a first component 90 that has a different (or non-complimentary) shape than the inverse of a beveled channel 96 recessed into a joint face 97 of a second component 95. This embodiment illustrates a concentric mating means for aligning a first component and a second component by a ridge and channel wherein the channel is not an inverse of the ridge. In another embodiment as illustrated in Figure 4, in an angle on angle configuration, the entire or part of a first component 60 with a first mating face 61 having a radial thickness 63 tapers toward a first ID 62 from a first OD 64 and the entire or part of a second component 65 with a second mating face 66 having a radial thickness 68 has an inverse taper toward a second ID 67 from a second OD 69. This embodiment illustrates a concentric mating means for aligning the first component 60 and the second component 65 by a taper and inverse taper towards the inner diameter 62, 64.

Alternatively, the entirety or part of the first mating face tapers 61 toward the first OD 64 and the entire or part of the second mating face 66 has an inverse taper toward the second OD 69. Furthermore, the mating faces may have any combination of a taper or inverse taper toward the ID and a taper or inverse taper toward the OD so that when pressed together, the components self-align and the tool joint centerline coincides with the base pipe centerline. The tapers and inverse tapers may range from about 1° to about 89°. This embodiment illustrates a concentric mating means for aligning a first component and a second component by a taper and inverse taper towards the outer diameter in combination with a plurality of concentric ridges and channels.

As illustrated in the 'sharp tongue and groove' configuration of Figure 5, a ridge 101 on a joint face 102 of a first component 100 may be conical and a channel 106 on a joint face 107 of a second component 105 has beveled edges 108 to receive the ridge 101. This embodiment illustrates a concentric mating means for aligning the first component (or tool joint) 100 and the second component (or base pipe) 105 by the conical ridge 101 and conical channel 106.

As illustrated in Figure 3, the ridge 33 and channel 43 may be beveled to form a trapezoidal profile. This beveling may aid concentric self-alignment and increase the interface surface area. The bevel angle Θ may range from about Γ to about 89°. Furthermore, the bevel of the ridge 33 need not be the complementary inverse of the bevel of the channel 43. The bevel of the ridge 33 may be a different angle than the bevel of the channel 43.

In a non-limiting example, a first component may have a ridge on the first mating face near the first component OD and a channel near the first component ID. A corresponding second component may have a channel on the second mating face near the second component OD, a channel near the middle of the second component thickness, and a ridge near the second component ID. Each channel shape is substantially the inverse or is complimentary with the ridge of the opposing component so that when pressed together, the first component and the second component self-align to be concentric to a common axis.

The mating means, including but not limited to lip and ledge, taper and inverse taper, and ridge and channel, may be used in combination to form mating surfaces that cause the components to concentrically self-align when pressed together. There are infinite variations and combinations of these mating means. As illustrated in the 'double sharp' tongue and groove configuration shown in Figure 6, the first component 70 has a taper 71 on a first component OD 77, an OD curved channel 72 near the first component OD 77, an ID curved channel 74 near a first component ID 76, and a middle curved ridge 73 between the OD curved channel 72 and the ID curved channel 74 giving an undulating first mating face 75 across the first component radial thickness 78. The second component 80 has an inverse taper 81 on a second component OD 87, an OD curved ridge 82 near the second component OD 87, an ID curved ridge 84 near a second component ID 86, and a middle curved channel 83 between the OD curved ridge 82 and the ID curved ridge 84 giving an undulating second mating face 85 across a second component radial thickness 88 that is substantially the inverse of the first mating face 75. Pressing the first mating face 75 to the second mating face 85 causes the first component 70 and second component 80 to self-align concentrically about a common axis 79 because of the mating taper, ridge, and channel combination.

Furthermore, as illustrated in the 'tongue and groove with taper configuration' shown in Figure 8, the features on each mating face need not be inverses of each other to cause concentric self-alignment when pressed together. This embodiment illustrates a concentric mating means for aligning a first component 110 and a second component 120 by dissimilar features. The first component 110 has an ID 114, an OD 115, an inverse taper 113 on the first component OD 115, and a ridge 111 on a first mating surface 112. Both the inverse taper 113 and the ridge 111 are concentric about a first centerline 116. The second component 120 has an ID 124, an OD 125, a beveled channel 121 that is depressed below a face 122 of the second component 120 and is concentric about a second centerline 126. When the first component 110 and the second component 120 are pressed together, the ridge 111 passes into part of the channel 121 and causes the first mating face 112 to contact the second mating face 122 in concentric alignment such that the first centerline 116 and the second centerline 126 coincide. The channel 121 of the second component 120 is not the inverse of the inverse taper 113 and ridge 111 of the first component 110. The mating means of the first component and second component may have dissimilar features that cause concentric alignment as illustrated in Figures 6, 7, and 8.

As illustrated in Figure 10 is another embodiment, the 'long bevel with similar tapers' configuration, in which a first component 130 and a second component 140 have dissimilar geometries. The first component 130 has an OD 131, a center line 145, an ID 132 and a radial thickness 133. The second component 140 has an OD 141, an ID 142 and a radial thickness 143. The OD 131 of the first component 130 may be smaller than the OD 141 of the second component 140. A first mating face 134 on the first OD 131 has an inverse taper and a second mating face 144 on the second OD 141 has an inverse taper. When pressed together, the first mating face 134 contacts the second mating face 144, causing self-alignment of the first component 130 and the second component 140 such that the centerlines 135 and 145 coincide. In a non-limiting embodiment, both the first component 130 and the second component 140 are pipes of different sizes. This embodiment illustrates a concentric mating means for aligning a first component and a second component of a different geometry than the first component by a taper and an inverse taper towards the outer diameter

In another embodiment, a hollow or tubular first component may be concentrically self- aligned with a solid second component by the mating means described herein. As illustrated in Figure 11, the 'interfering ledges' configuration, a hollow component 150 with a radial thickness 154, a first OD 156 and a first ID 152 has a beveled depressed ledge 153 on the first OD 156 below a pipe face 155 of a mating face 157. A solid component 160 with a second OD 166 has a raised beveled surface 163 as part of a mating face 162. The first OD 156 and the second OD 166 are dissimilar. The raised surface 163 is centered on the solid centerline 161 whereas the ledge 153 is centered on a hollow centerline 151. The raised beveled surface 163 mates with the depressed ledge 153 when the components of the mating faces 157, 162 are pressed together and/or the pipe face 155 interfaces with a solid face 165 of the solid component 160 such that the hollow component 150 and the solid component 160 are concentrically self-aligned. This embodiment illustrates a concentric mating means for aligning a first tubular component and a second solid component with a different geometry by a depressed ledge and a raised beveled surface. This embodiment also illustrates the welding of a solid body to a hollow body by the means provided for in this invention and equally applies with any of the before mentioned mating features and methods.

In an alternative embodiment, a first hollow component may have a larger OD than a second component. The first mating face and second mating face include mating means for concentric alignment. When the first component is friction welded to the second component, a portion of the inner diameter of the hollow component encloses a portion of the second component forming a fused slip joint. The second component may be hollow or solid.

In yet another embodiment, a first component has a cylindrical flange with a first mating face centered on a first axis. The cylindrical flange may be on a cylindrical or non-cylindrical component. A second component has a cylindrical end or flange with a second mating face centered on a second axis. The second mating face may be pressed to contact and align with the first mating face such that the first axis and the second axis coincide in a common axis. The second component may then be rotated about the common axis and friction welded to the cylindrical flange.

As illustrated in Figure 12, a cylindrical flange 171 with a flange diameter 172 may also be recessed within a first component 170. The cylindrical flange 171 is surrounded by a circular channel 173 that is the mating means to concentrically align the first component 170 with a second component 175. By this method, non-concentric components may be viably welded together providing the features in the mating surfaces are concentric. This embodiment illustrates a concentric mating feature recessed in a non-concentric stationary component wherein the rotating mating component mates along the axis of the feature.

Referring now to Figure 13, the features on each mating face need not be inverses of each other to cause concentric self-alignment when pressed together and may consist of male only features on each mating face, and so is called the "male only" configuration. A first component 180 has a ridge 181 on a first mating surface 182 that is concentric about a first centerline 183. A second component 185 has a ridge 186 on a second mating surface 187 that is concentric about a second centerline 188. When the first component 180 and the second component 185 are pressed together, the ridge 181 passes on the outside of the ridge 186 on the second mating surface 187 and causes the first mating surface 182 to contact the second mating surface 187 in concentric alignment such that the first centerline 183 and the second centerline 188 coincide. As the friction welding proceeds, the ridges (or male projections) 181, 186 will be fused with the mating surfaces 182, 187, or may be consumed in the welding process. This embodiment illustrates the "male only" method of mating features and is not limited to the use of the ridge 181 as illustrated, but rather includes all potential "male" mating features denoted in this application, such as ridges, tongues, trapezoids, beads, etc. This embodiment illustrates a concentric mating means for aligning a first component and a second component of a different geometry than the first component where both components have only male features

Another example of the all-male features configuration is shown in Figure 14, where a first component 190 has a ridge projection 191 on a first mating surface 192 that is concentric about a first centerline 193. A second component 195 has a projection 196 on a second mating surface 197 that is concentric about a second centerline 198. When the first component 190 and the second component 195 are pressed together, the ridge projection 191 passes on the outside of the projection 196 on the second mating surface 197 and causes the first mating surface 192 to contact the second mating surface 197 in concentric alignment such that the first centerline 193 and the second centerline 198 coincide. As the friction welding proceeds, the male projections 191, 196 will be fused with the mating surfaces 192, 197 or may be consumed in the welding process.

As shown in Figures 15-18, in an alternate embodiment of the present invention there can be used other components in addition to the first component and the second component. In one non-limiting example a third component such as an insert, mandrel, ferrule, or sleeve is placed between the first component and the second component therein the first, second, and third components align amongst themselves to align the first and second centerlines when the three components are pressed together. The third component may be fused with the mating surfaces, may be eventually removable, or may be consumed in the welding process. These embodiments illustrate two concentric mating means for aligning a first component and a second component with the same end geometry by using an intermediate component having male and/or female features that are of the opposite the geometry of their respective mating first or second component. The first component and the second component material, as well as any other component that may be used herein, may be selected from any suitable material, such as metals and alloys of aluminum, steel, stainless steel, brass, bronze, carbon steel, copper, ferrous materials, iron, magnesium, nickel, titanium, and zinc. The components may also be selected from any suitable non-metallic material, such as for example plastics, resins, ceramics, or other non-metallic materials. The first component and the second component, as well as any other component that may be used herein, need not be the same material to be friction welded together, but they may be the same material.

In the embodiment as shown in Figures 15 and 16, the mating means of a tool joint 200, 230, 250, 270 and a base pipe 210, 240, 260, 280 may be formed with an intermediate component. The intermediate (or third) component may be made of , for example, a similar material to the base pipe and/or tool joint, or a different material, such as ceramic. The intermediate component may have various shapes or forms, such as an alignment ferrel 220 (as shown in Figure 15), an alignment sleeve 225 (as shown in Figure 16), a disposable disk 227 (as shown in Figure 17), and/or removable mandrel 229 (as shown in Figure 18). The intermediate component 220, 225, 227, 229 may be removed after welding, or consumed when the tool joint 200, 230, 250, 270 and base pipe 210, 240, 260, 280 are formed together. The mating means of the tool joint and base pipe may be formed when the tool joint and base pipe are formed. The mating means may be formed on the components by a computer numeric control (CNC) turning process. Additionally, the mating means may be added later by attaching to the end of the tool joint or base pipe by welding or other means. Furthermore, portions of the tool joint and base pipe may be removed to form the mating features. Features may be added by dies, die cutting, forging, stamping, turning, milling, or CNC machining as non-limiting examples.

Additionally, if a tool joint and base pipe have opposing female mating features including, but not limited to, a depressed ledge or channel, a separate circular component may be inserted into one of the female mating features to convert the female component to a male component. This separate circular component may be attached to one of the female mating features or pressed into the female mating feature. Furthermore, this separate circular component may be of any shape that causes the mating faces to concentrically self-align when the components are pressed together. When fusing a first component to a second component, the first component is placed inside the center of a chuck. This chuck may rotate the first component about the first component centerline and translate the first component along this centerline. The second component is placed on a surface that permits the second component to move in concentric alignment with the first component, generally without moving along the chucks axis. The chuck presses the first component mating face to the second component mating face, causing the second component to self-align to be concentric with the first component along a common axis. Once aligned, the second component is fixed in this concentric position and the first component is removed from the second component. The chuck rotates the first component and presses the first component into contact with the second component to friction weld the components together to form a fused component. Excess material or flash may then be removed from the OD and optionally ID of the fused component. In an embodiment, the first and second components may be hollow or solid in any combination. In another embodiment, the first component is a tool joint and the second component is a base pipe, wherein the fused component is a drill pipe.

Alternatively, the mating faces of the first component and the second component self- align to be concentric with the first component along a common axis when the chuck rotates the first component and presses the first component into contact with the second component. After the second component self-aligns to be concentric with the first component, the second component is fixed in this concentric position while the friction welding continues.

Alternatively, the second component may be rotated and the first component may be fixed after self-aligning to be concentric with the second component.

The method of the invention is not to be restricted to drill pipe, but is intended to be used for concentric alignment of all welded components, in particular concentric friction welded components. Other components included in the present invention include threaded connections, coiled tubing, tubing, casing, downhole stabilizers, bits, motors, pumps, agitators, production tools, completion tools, measurement tools, axles, drive shafts, rods, reactors, vessels, beams, columns, wires, conduits, and ducts.

Figure 19 is a flow chart depicting a method 1900 of welding a downhole component, such as a drill pipe. As shown, the method involves providing 1960 a first downhole component having a first mating feature on at least one end thereof and at least one second downhole component having a second mating feature on an end thereof weldably connectable to the end of the first downhole component (the first and second mating features including at least one raised ridge), concentrically 1962 self-aligning along a common axis the first and second mating features, and foraiing 1964 a welded connection between the first downhole component and the second downhole component by frictionally engaging the end of the first downhole component with the end of the second component under heat and pressure. The steps of the method may be performed in any order and repeated as desired.

Various terms are used herein, to the extent a term used is not defined herein, it should be given the broadest definition persons in the pertinent art have given that term as reflected in printed publications and issued patents. Various ranges are further recited herein. It should be recognized that unless stated otherwise, it is intended that the endpoints are to be

interchangeable. Further, any point within that range is contemplated as being disclosed herein

Use of the term "raised" or "positive" with respect to the mating means, features of the joint face, or features of the pipe face refer to a shape that extends outward from a reference surface. Use of the term "depressed" or "negative" with respect to the mating means, features of the joint face, or features of the pipe face refers to a shape that extends inward from a reference surface.

Use of broader terms such as comprises, includes, having, etc., should be understood to provide support for narrower terms such as consisting of, consisting essentially of, comprised substantially of, etc.

Use of the term "optionally" with respect to any element of a claim is intended to mean that the subject element is required, or alternatively, is not required. Both alternatives are intended to be within the scope of the claim. Use of broader terms such as comprises, includes, having, etc. should be understood to provide support for narrower terms such as consisting of, consisting essentially of, comprised substantially of, etc.

Depending on the context, all references herein to the "invention" may in some cases refer to certain specific embodiments only. In other cases, it may refer to subject matter recited in one or more, but not necessarily all, of the claims.

While the foregoing is directed to embodiments, versions and examples of the present invention, which are included to enable a person of ordinary skill in the art to make and use the inventions when the information in this patent is combined with available information and technology, the inventions are not limited to only these particular embodiments, versions and examples. Other and further embodiments, versions, and examples of the invention may be devised without departing from the basic scope thereof and the scope thereof is determined by the claims that follow.

Whereas the present invention has been described in particular relation to the drawings attached hereto, it should be understood that other and further modifications apart from those shown or suggested herein, may be made within the scope and spirit of the present invention.

Claims

CLAIMS What is claimed is:

1. A downhole tool deployable into a wellbore penetrating a subterranean formation, the downhole tool comprising: a first downhole component having a first mating feature on at least one end thereof; and at least one second downhole component having a second mating feature on an end thereof

weldably connectable to the at least one end of the first downhole component;

wherein at least one of the first and second mating features comprises at least one raised ridge for concentric self-alignment along a common axis with the other of the first and second mating features whereby, upon frictional engagement of the end of the first downhole component with the end of the second component under heat and pressure, a welded connection is formed therebetween.

2. The downhole tool of Claim 1, wherein at least one of the first and second mating features comprises at least one channel for receiving the at least one raised ridge.

3. The downhole tool of Claim 1, wherein the first downhole component comprises a base pipe and the second downhole component comprises a pair of tool joints weldable to each end of the base pipe to form a drill pipe.

4. The downhole tool of Claim 1, wherein the first and second downhole components each comprise a pipe.

5. The downhole tools of Claim 1, wherein the first downhole component comprises a pipe and the second downhole component comprises a bar.

6. The downhole tool of Claim 1, wherein the first and second components are concentric along the common axis.

7. The downhole tool of Claim 1, wherein the first and second components are non- concentric along the common axis.

8. The downhole tool of Claim 1, wherein the first downhole component has the same outer diameter as the at least one second downhole component.

9. The downhole tool of Claim 1, wherein the first downhole component has a different outer diameter from the at least one second downhole component.

10. The downhole tool of Claim 1, wherein the at least one ridge is one of conical, rounded, and beveled.

11. The downhole tool of Claim 1, wherein the at least one channel is one of conical, rounded, and beveled.

12. The downhole tool of Claim 1, wherein the first and second mating features are complimentary.

13. The downhole tool of Claim 1, wherein the first and second mating features are non- complimentary.

14. The downhole tool of Claim 1, wherein the at least one end of the first downhole component and the end of the second downhole component each have a seating surface.

15. The downhole tool of Claim 14, wherein the seating surface is perpendicular to a longitudinal axis of the first and second downhole components.

16. The downhole tool of Claim 1, wherein the first downhole component is recessable a distance into the at least one second downhole component.

17. The downhole tool of Claim 16, wherein the second downhole component comprises a flange recessed a distance therein for receiving the first downhole component.

18. The downhole tool of Claim 1, further comprising a third downhole component positionable between the first and second downhole components.

19. The downhole tool of Claim 18, wherein the third downhole component comprises one of a ferrel, a sleeve, a disc, a mandrel and combinations thereof.

20. The downhole tool of Claim 1, wherein each of the first and second components are one of hollow, solid, and combinations thereof.

21. A downhole tool deployable into a wellbore penetrating a subterranean formation, the downhole tool comprising:

a first downhole component having a first mating feature on at least one end thereof;

at least one second downhole component having a second mating feature on an end thereof

weldably connectable to the at least one end of the first downhole component; and a third downhole component positionable between the first and second downhole components for concentric alignment therebetween along a common axis whereby, upon frictional engagement of the end of the first downhole component with the end of the second component under heat and pressure, a welded connection is formed therebetween.

22. The downhole tool of Claim 21, wherein the third downhole component is removable.

23. The downhole tool of Claim 21, wherein the third downhole component is consumed during welding.

24. A method for welding a downhole tool deployable into a wellbore penetrating a subterranean formation, the method comprising:

providing a first downhole component having a first mating feature on at least one end thereof and at least one second downhole component having a second mating feature on an end thereof weldably connectable to the at least one end of the first downhole component, the first and second mating features comprising at least one raised ridge;

concentrically self-aligning along a common axis the first and second mating features; and forming a welded connection between the first downhole component and the second downhole component by frictionally engaging the at least one end of the first downhole component with the end of the at least one second component under heat and pressure.

25. The method of Claim 24, wherein the forming further comprises rotating the first component.

26. The method of Claim 24, wherein the forming further comprises maintaining the second component in a stationary position.

27. The method of Claim 24, wherein the matingly engaging comprises interfitting the first mating feature with the second mating feature.

28. The method of Claim 24, wherein the step of mating comprises self-aligning the first mating feature with the second mating feature.

29. The method of Claim 24, further comprising inserting at least one additional component between the first downhole component and the second downhole component.

30. The method of Claim 29, further comprising consuming the at least one additional component in the forming of a welded connection.

31. The method of Claim 24, further comprising consuming at least a portion of the first and second mating features in the forming of a welded connection.

32. The method of Claim 24, wherein the forming comprises one of friction welding, fusing and combinations thereof.

33. The method of Claim 24, wherein the first and second downhole components are fused together according to concentricity and angularity tolerances.