Well pipe with conductor having improved electrical contacts

Abstract

A well pipe having a conductor includes at least one pipe segment having a hole or channel extending along the length of the pipe segment between a first threaded connection at one end and a second threaded connection at the other longitudinal end. At least one insulated conductor extends along the hole or channel. Receiving features are positioned at each of the first and second threaded connections to receive an electrical contact assembly. The electrical contact assembly includes an insulating material having a retaining feature for arranging at least one electrical contact internally. The at least one electrical contact is electrically connected to at least one insulated conductor, where at least a portion of the at least one electrical contact is exposed from the retaining feature.

Description

[[Technical Field]]

[0001] Background Art The present disclosure relates to, but is not limited to, the field of underground well construction. More particularly, the present disclosure relates to a structure for a pipe used in the completion of such wells, wherein the pipe has one or more insulated conductors used as power and / or signal channels.

[0002] Patent Document 1 and Patent Document 2 describe structures and methods for producing a well drilling pipe (drill pipe) having insulated conductors that may be used as a channel for power and signal communication between the surface and one or more electric downhole tools while a well is being drilled. Generally, the pipes described in the aforementioned publications use industry-standard sections (joints) of drill pipe. Each joint of pipe has an electrical insulation layer inserted on the inner surface of the pipe joint, and a conductor structure radially expanded relative to and bonded to the insulation layer. The conductor structure is fabricated such that it can expand radially, contract longitudinally as a result of radial expansion, and does not undergo plastic deformation due to radial expansion.

[0003] The pipe structure disclosed in the aforementioned publications is particularly adapted to the conditions during well drilling, in particular the bending and cyclic torsional stresses applied to the assembled joints of pipe (the pipe "string") during movement in the wellbore, repeated axial loading and unloading, and repeated tightening and loosening of threaded connections between joints or "stands" (joints assembled into sections of two, three or four joints) as well drilling progresses. It is contemplated that such drill pipes are scrapped due to metal fatigue or because the threaded connections at the longitudinal ends of each pipe joint become unusable as a result of repeated recutting of such threaded connections of the pipe joints. Recutting of threaded pipe connections is used to keep drill pipes in service after the threaded connections are damaged during use and handling.

[0004] More recently, there has been interest in the use of so-called "wired" pipes to provide power and signal communication channels for wells that have been drilled, requiring the installation of casings or liners to protect exposed rock formations and to seal the well from fluid movement between rock formations at different depths. Such casings or liners are known to be placed inside the well after drilling is complete, and are typically held in place within the well by cement. The casings or liners may then be completed by drilling into rock formations from which fluids such as oil and gas are expected to be produced. The corresponding conditions may also apply to wells in which one or more hydraulic or pneumatic control lines may be used, for example, to operate inflow control devices or safety valves.

[0005] Casings or liners may be reasonably expected to be exposed to flowing fluids over long periods and, in some cases, to high temperatures depending on the depth to which the fluid enters the well. As a result, conductor-containing casings or liners fabricated as described in the aforementioned publications for drilling pipes may not be optimal for such conditions. The pipe structures disclosed in the aforementioned patent publications are not suitable for use in hydraulic and / or pneumatic control lines. The aforementioned problems may be understood equally to apply to smaller diameter pipes called tubing, which are typically fitted into casings or liners within wells. Collectively, such pipes are called well-finishing pipes, well-construction pipes, well pipes, or well-hole pipes. This term may be referred to as (wellbore tubular), and the aforementioned terms may be used interchangeably in this disclosure.

[0006] Patent Document 3 describes the structure of a well pipe having an axial channel which may enclose one or more conductors or one or more hydraulic lines. In the case of a conductor, in order to extend the conductor along the entire axial length of the assembled pipe segments, it is necessary to provide electrical contacts close to each axial end of each pipe segment so that when the pipe segments are assembled end to end, the electrical contacts in adjacent pipe segments are biased to contact each other, forming an electrical connection. The disclosed electrical contacts may be improved.

[0007] Therefore, a well pipe having one or more insulated conductors is required, which has improved electrical connections between assembled adjacent pipe segments. [Prior art documents] [Patent Documents]

[0008] [Patent Document 1] Canadian Patent No. 3,002,675 [Patent Document 2] U.S. Patent No. 11,236,551 [Patent Document 3] Brochure for International Patent Application Publication No. WO / 2022 / 224149 [Overview of the initiative]

[0009] One aspect of the present disclosure is a well pipe having at least one insulated conductor. The well pipe according to this aspect includes at least one pipe segment having a hole or channel extending along the length of the pipe segment between a first threaded connection at one end and a second threaded connection at another longitudinal end. The at least one insulated conductor extends along the hole or channel. Receiving features are provided at each of the first and second threaded connections for receiving an electrical contact assembly. The electrical contact assembly includes an insulating material having a retaining feature for arranging at least one electrical contact internally. The at least one electrical contact is electrically connected to at least one insulated conductor, where at least a portion of the at least one electrical contact is exposed from the retaining feature.

[0010] In some implementations, the surface angle of the insulating material is oblique, the radius of curvature defined by the electrical contacts of the first screw connection is different from the radius of curvature defined by the electrical contacts of the second screw connection, or the retaining feature defines a circular cross-sectional groove that traverses more than 180 degrees of the circumference around the electrical contacts located inside.

[0011] In some implementations, the insulating material includes a longitudinal extension that protrudes from one side of the surface of the insulating material.

[0012] In some implementations, the longitudinal extension includes a taper.

[0013] In some implementations, the first threaded connector and the second threaded connector each include a male threaded connector.

[0014] Some implementations further include at least one pipe connector having a female threaded connection at each longitudinal end. Each female threaded connection of the at least one pipe connector includes a receiving feature for receiving an electrical contact assembly. The electrical contact assembly of each female threaded connection includes an insulating material having a retaining feature for arranging at least one electrical contact internally. The at least one electrical contact is connected to the female threaded connection at each longitudinal end. It is electrically connected to at least one insulated conductor located within a hole extending between the parts. In one or both female connectors, at least a portion of the at least one electrical contact is exposed from the retaining feature.

[0015] In some implementations, the at least one pipe connector has at least one of the following characteristics: (i) the surface angle of the insulating material is oblique; (ii) the radius of curvature defined by the electrical contacts of the threaded connection is different from the radius of curvature defined by the electrical contacts of at least one threaded connection of the pipe segment; or (iii) the retaining feature defines a circular cross-sectional groove that traverses more than 180 degrees of the circumference around the electrical contacts located inside.

[0016] In some implementations, a retaining feature for receiving an electrical contact assembly of at least one pipe connector cooperates with a receiving feature for receiving an electrical contact assembly of either a first threaded connection or a second threaded connection of the at least one pipe segment to form a pressure isolation chamber, where the electrical contact assembly of the female threaded connection and the electrical contact assembly of the first threaded connection or the second threaded connection of the at least one segment of the pipe are positioned within the chamber when the first threaded connection or the second threaded connection is assembled to the female threaded connection.

[0017] In some implementations, the receiving feature for receiving the electrical contact assembly of the female threaded connection includes an expanded space for insulating material.

[0018] In some implementations, the at least one pipe connector comprises a casing collar.

[0019] In some implementations, the receiving features respectively disposed on the first threaded connection portion and the second threaded connection portion comprise an expanded space for insulating material.

[0020] In some implementations, assembling the first threaded connection portion to a corresponding threaded connection portion on an adjacent pipe segment or pipe connector defines a chamber isolated from fluid pressure outside the well pipe and from within the interior of the pipe by forming a metal-to-metal seal.

[0021] In some implementations, the insulating material comprises an elastomer.

[0022] In some implementations, the electrical contact is retained within the retaining feature by an adhesive.

[0023] Other aspects and potential advantages will be apparent from the following description and the claims. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] [Figure 1] Figure 1 shows a cross-section of an assembled segment (joint) of an exemplary implementation of a well pipe according to the present disclosure. [Figure 2] Figure 2 shows an enlarged view of an insulated electrical contact in adjacent pipe segments of the implementation shown in Figure 1. [Figure 3] Figure 3 shows another enlarged view similar to Figure 2, illustrating an exemplary implementation of an electrical insulator. [Figure 3A] Figure 3A shows an enlarged view similar to Figure 3, having a different shape for an electrical insulator with a longer leakage path. [Figure 4] Figure 4 shows an enlarged view of one of the electrical insulators of Figure 3. [Figure 4A] Figure 4A shows an enlarged view of one of the electrical insulators of Figure 3A [Figure 5]Figure 5 shows an exemplary implementation of electrical contacts in adjacent pipe segments arranged to be in contact with each other. [Figure 6] Figure 6 shows a perspective view of the female end of the pipe segment, i.e., the box end, indicating the arrangement of electrical contacts and insulating material. [Figure 7] Figure 7 shows a perspective view of the two conductive electrical contacts and the insulating material. [Figure 8] Figure 8 shows a diagram of a two-conductor contact without highlighting the insulating material. [Figure 9] Figure 9 shows the electrical contacts and associated conductors of Figures 6 and 7. [Figure 10] Figure 10 shows an exemplary implementation of an electrical contact on the male, or pin end, of a pipe segment. [Figure 11-13] Figures 11, 12, and 13 show diagrams corresponding to Figures 7, 8, and 9, which lack the electrical contacts shown in Figure 10 and have only one conductor. [Figure 14] Figure 14 shows a partial cut-off of the conductor and contact at one end of a pipe segment, where the conductor has a bending stiffness reduction feature. [Figure 15] Figure 15 shows a magnified view of the exemplary conductor in Figure 14 to better illustrate the bending stiffness reduction feature. [Figure 16] Figure 16 shows a partially cutaway side view of another exemplary embodiment of a conductor having an axial strain relief section. [Figure 17] Figure 17 shows a magnified view of the conductor in Figure 16 to better illustrate the axial strain relaxation feature. [Figure 18] Figure 18 shows an exemplary embodiment of a pipe segment and electrical contacts according to the present disclosure, having multiple insulated conductors and associated electrical contacts, which are useful, for example, in multiphase power transmission. [Figure 19] Figure 19 shows a perspective view of the pin end segment shown in the side perspective view of Figure 18. [Figure 20] Figure 20 shows an end view of the box end segment shown in the side perspective view of Figure 18. [Modes for carrying out the invention]

[0025] Detailed explanation Figure 1 shows an exemplary embodiment of an assembled well pipe segment (joint) 10 according to the present disclosure. The individual pipe segments shown 12 may include pipe structures known in the art for use in, for example, well construction, well completion and well intervention, and each axial end of each pipe segment 12 includes a male threaded end, i.e., a “pin” end. Each pin end of the pipe segment 12 may be assembled by thread into one female, i.e., a “box” end, of a double female-ended pipe connector referred to as a casing collar 14. The casing collar may be referred to as a “double box” segment, as some embodiments have a box connector at each longitudinal end.

[0026] While the exemplary embodiments described herein are described in terms of pipe segments having pin connections at each axial end, where the pipe segments are connected to one another by collars or other dual female-end connectors, it should be made clear that pipe segments having pins at one axial end and boxes at the other axial end are equally within the scope of this disclosure, as are so-called “dual-box” pipe segments having female thread connections at both longitudinal ends. Accordingly, in the following descriptions, structures described with reference to male thread connectors will be similar to any of the aforementioned possible pipe embodiments; correspondingly, structures described with reference to female thread connectors will be similar to any of the aforementioned pipe embodiments.

[0027] In the exemplary embodiment shown in Figure 1, each pipe segment 12 may include an outer pipe 112, and an intermediate layer 312 may be fitted inside the outer pipe 112. 2 may be fitted into the intermediate layer 312. The intermediate layer 312 may contain, form, or have holes or channels 312A extending along the length of the intermediate layer 312. In some non-limiting exemplary embodiments of the structure of the outer pipe 112, the intermediate layer 312 and the inner pipe 212 may be described in Patent Document 3 Al, which has been assigned to the assignees of this disclosure. However, it should be understood that the structures described in the aforementioned publications are merely examples of possible pipe structures applicable to this disclosure and are not intended to limit the scope of this disclosure. The channels or holes 312A may surround one or more insulated conductors 20. The axial ends of one or more insulated conductors 20 may be formed in or connected to a first electrical contact assembly 22. In exemplary embodiments, each longitudinal end of each pipe segment 12 may include such a first electrical contact assembly 22. In this exemplary embodiment, the casing collar (sometimes referred to as a collar) 14 may include a second electrical contact assembly 24 at a corresponding location on each longitudinal end. Each of the second electrical contact assemblies 24 is placed in physical contact with one of the first electrical contact assemblies 22 located on the corresponding pin end of an adjacent pipe segment 12 when the casing collar 14 is assembled to the pipe segment 12. One or more insulated conductors 26 may extend axially along the casing collar 14 within a corresponding longitudinal hole 126 that itself extends along the casing collar 14.

[0028] In this exemplary embodiment, the inner pipe 212 may extend longitudinally beyond the longitudinal end of the outer pipe 112, such that the inner pipe 212 may have an inner threaded connection 12B formed on its outer surface, thereby defining the inner threaded connection 12B. Similarly, the outer pipe 112 may have an outer threaded connection 12A formed thereon, thereby defining the outer threaded connection 12A. "Inner" and "outer" are used to mean radial positions relative to the longitudinal axis L of the pipe segment 12. Such threaded connections 12A, 12B may mate with corresponding outer and inner threaded connections 14A, 14B formed on the inner surface of the casing collar 14. When assembled, the corresponding threaded connections may have, for example, appropriately spaced inner and outer, axially separated shoulders, thereby forming a metal-to-metal seal by defining a pressure isolation chamber 23 between adjacent assembled pin-and-box connections. In this context, it will be recognized that “pressure-sealing” refers to the ingress of fluid from outside the assembled pipe segment and from inside the inner pipe 212. The hole or channel 312A may provide a longitudinal fluid passage along the pipe segment 12 until the pipe string is fully assembled. In this exemplary embodiment, the arrangement of the inner pipe 212, outer pipe 112 and associated threaded connections 12B, 12A within the casing collar 14, and the mating threaded connections, causes the pressure isolation chamber 23 to be longitudinally positioned (axially) between or between the inner threaded connection 12B and the outer threaded connection 12A. For the purposes of defining the scope of this disclosure, however, it should be understood that it is only necessary to provide the pressure isolation chamber at any longitudinal position along the threaded connections so that such a pressure isolation chamber is defined by assembling the pipe segment and / or collar from end to end.

[0029] It should be further understood that the implementation shown in Figure 1, in which the channel or hole 312A is positioned within the intermediate layer 312, is intended to serve only as an example of a method for implementing an insulated conductor extending along the length of the pipe segment. For example, it is equally possible to fabricate the pipe segment 12 from a single tube and form threads defining the pressure isolation chamber described when assembled to adjacent devices (e.g., pipe segments or casing collars), and furthermore, the hole or channel 312A may be formed by longitudinal drilling through the wall of such a single tube, extending between the pressure isolation chamber defining features at each longitudinal end of the single tube. It is also within the scope of this disclosure that each or any portion of several pipe segments includes a pin connection at one longitudinal end, as shown in Figure 1, a box connection at the other longitudinal end, or a box connection at each longitudinal end. In such implementations, the components shown on one longitudinal side of the casing collar 14 would be formed corresponding to one or more of each pipe segment, or to the other longitudinal end.

[0030] Figure 2 shows an enlarged view of a pipe segment (12 in Figure 1) assembled to a casing collar (14 in Figure 1) to show in more detail the first and second electrical contact assemblies 22, 24. The first electrical contact assembly 22 may be located at the longitudinal end of a channel or hole (312 in Figure 1), as shown in 12C in Figure 2. In some implementations, as shown in Figure 2, an axial or longitudinal space may be formed between an internal thread 12B and an external thread 12A to provide a stop or shoulder 12C4 that restricts the longitudinal movement of the electrical insulating material 22A (hereinafter, for convenience, the "insulating material"), which may be formed from an elastomer or other elastic, electrically insulating material. The stop or shoulder 12C4 may be referred to as a "receiving feature" because its function is ultimately to receive and hold the electrical contact assembly. The first electrical contact assembly 22 may include an insulating material 22A positioned as described above, located on a shoulder 12C4 at the longitudinal end of a channel or hole 12C. The electrical contact 22B may be located within a retaining feature, for example, a groove (described in more detail in relation to Figure 4), so that the electrical contact 22B is at least partially exposed (and may partially protrude beyond the surface of the insulating material 22A) adjacent to the open longitudinal end of the retaining feature within the insulating material 22A. The second electrical contact assembly 24 may be located within a corresponding portion of a casing collar (14 in Figure 1) or at the longitudinal end of a receiving feature. The second electrical contact 24 may include an insulating material 24A, which may be formed from an elastomer or other resilient insulating material 22A, such as the insulating material 22A in the first electrical contact assembly 22, and the electrical contact 24B is located within a corresponding retaining feature within the insulating material 24A. As shown in Figure 2, when the pin ends are assembled to the box ends by screws, the first electrical contact assembly 22 is biased to contact the second electrical contact assembly 24, thereby causing the corresponding electrical contacts 22B and 24B to contact each other, and the elastomeric properties of the respective insulating materials 22A and 24A provide an axial biasing force, which may form a good electrical connection between the respective contacts 22B and 24B.It will be recognized that the threaded connections and conductive / contact assemblies / contact structures described in relation to the casing collar 14 may be used in the implementation of well pipes that include box connections at one or both of the longitudinal ends.

[0031] In an exemplary embodiment shown in Figure 2, and also referring here to Figure 3, the casing collar (14 in Figure 1) and the pin end of the pipe (12 in Figure 1) may have corresponding features indicated by 14D, 12D formed within the outer wall of the pressure isolation chamber feature, providing space for the insulating materials 22A, 24A to expand radially as they are biased (therefore compressed longitudinally) to contact each other during the assembly of the corresponding pipe segments, in this embodiment while the pipe segments are assembled against the collar. In some embodiments, and also as shown in Figure 3, the respective longitudinal end faces of the insulating materials 22A, 24A may define an angle A, which may be oblique, with respect to the longitudinal axis of the pipe segment. Such an angle A may provide a device to facilitate the drainage of any liquid that may accumulate on the longitudinal end faces of either or both of the insulating materials 22A, 24A. Such drainage may flow into the respective expansion spaces 14D, 12D before the threaded assembly of the pipe segments, through inclined surfaces defined by such angles formed within the elastomer insulating material surface.

[0032] As shown in Figure 4, each insulating material, e.g., 22A, may have a retaining feature 22A1 on its "mating" surface 22F, and a corresponding electrical contact, e.g., 22B in Figure 3, may be located within the retaining feature 22A1. The mating surface 22F will be biased to contact the corresponding insulating material (e.g., 24A in Figure 3) when the pipe segments are assembled. The cross-section of the electrical contact (e.g., 22B in Figure 2) may have a shape such that the retaining feature may have, e.g., 22A1, so that the insulating material tends to retain the electrical contact within the retaining feature 22A1, and thus within the body of the insulating material 22A. In a non-limiting example, the electrical contact 22B may have a circular cross-section (see, e.g., Figure 5), and the retaining feature 22A1 may form a circular cross-sectional channel that traverses more than 180 degrees but less than 360 degrees of the circumference. In this manner, at least a portion of the electrical contact 22B may be exposed and form a galvanic contact with an adjacent electrical contact (e.g., 24B in Figure 5) while being firmly held inside the retaining feature 22A1. During assembly, the electrical contacts (e.g., 22B, 24B in Figure 5) may be pushed into the retaining feature 22A1, thereby allowing the elastic displacement of the insulating material to allow the electrical contact to move completely into the retaining feature 22A1, and the insulating material (e.g., elastomer) to return almost to its unstressed shape. Such a return to an unstressed state will cause the electrical contact 22B to be held inside the retaining feature 22A1. The retaining feature may traverse less than 180 degrees, and in some embodiments, it will be recognized that the electrical contact 22B may be held inside the retaining feature by means of an adhesive, for example.

[0033] Some implementations of the insulating materials 22A, 24A, returning to Figure 3A, may include longitudinal extensions 22C, 24C from their respective surfaces 22F, 24F. When the insulating materials 22A, 24A are biased into longitudinal contact, the longitudinal extension on one insulating material 22C, 24C engages with the outer surface of the opposing insulating material 24A, 22A, respectively. Such longitudinal extensions 22C, 24C provide increased length of surface contact of the insulating materials 22A, 24A with the opposing insulating materials 24A, 22A, thereby increasing the length of the leakage path along the joint between the insulating materials 22A, 24A. Thus, the electrical insulation of assembled pipe segments associated with the insulating materials shown in Figures 2, 3, and 4 may be improved even with only a small amount of conductive material on the insulating materials 22A, 24A, such as a film. Such material may be, but is not limited to, brackish water or saltwater. The longitudinal extensions 22C and 24C may include tapers 22C1 and 24C1, respectively, to facilitate the engagement of the insulating materials 22A and 24A with each other when the pipe segments are assembled.

[0034] In some implementations, also referring to Figure 5, the first electrical contact 22B may define a first radius of curvature R1, and the second electrical contact 24B may define a second radius of curvature R2 that is different from the first radius of curvature R1, for example, a larger second radius of curvature R2. In this way, when the first electrical contact 22B is axially biased to contact the second electrical contact 24B, the defined contact angle B between the diameters of the electrical contacts is oblique with respect to the longitudinal axis of the pipe segment. Such an oblique angle B may provide an increased contact force between the electrical contacts 22B, 24B by both the axial and radial components of the force applied between the two electrical contacts 22B, 24B, thereby improving the conductivity between the electrical contacts 22B, 24B. In some implementations, one or both of the electrical contacts 22B, 24B may be formed from an elastic spring metal such as phosphor bronze to provide an additional contact force between the electrical contacts 22B, 24B as described above.

[0035] Figures 6–9 show various diagrams of another exemplary embodiment of an electrical contact assembly according to the present disclosure, having two or more electrical contacts and two or more insulated conductors. The illustrated electrical contact assemblies may be electrically connected to corresponding electrical contact assemblies located within adjacent connected pipe segments or collars. The embodiment shown in Figure 6 is a box end connection in the present disclosure. The diagram shows one of the second electrical contact assemblies 24 located within or adjacent to a section (e.g., 14), but as described elsewhere in this specification, a corresponding structural device may be provided that biases the first electrical contact assembly (e.g., 22 in Figure 2) into contact by assembling adjacent pipe segments or pipes into a collar. The second electrical contact assembly 24 comprises an insulating material 24A, for example, an elastomer or other elastic electrical insulating material formed as described elsewhere in this specification, and may have retaining features (further described below) such as grooves (see 22A1 in Figure 4) in which electrical contacts may be located.

[0036] Figure 7 shows a second electrical contact assembly 24 separated from the pipe segment (14 in Figure 6). The insulating material 24A may include one or more indexing tabs 24A2 on the face opposite the retaining feature 24A1 (e.g., a groove). One or more indexing tabs 24A2 may project from the opposing face and extend into a corresponding receptacle (not shown) formed within the pipe segment, or they may provide additional friction to reduce the possibility of the insulating material 24A simply rotating when adjacent pipe segments are screw-connected. In this exemplary embodiment, there may be two or more insulating conductors. The first conductor 20A may extend through a corresponding channel or hole in the pipe segment (e.g., see Figure 1). The first conductor 20A may terminate in the insulating material 24A within the first electrical contact segment 20A1. The segment 20A1 may take the form of a partial circumferential segment positioned within a portion of the circumference of the retaining feature 24A1. The second conductor 20B, like the first conductor 20A, may extend along a pipe segment through a corresponding channel or hole and terminate at a second electrical contact segment 20B1 located within a different circumferential segment of the retaining feature 24A. It will be recognized that the first 20A1 and second 20B1 contact segments may include any or all of the aforementioned devices, such as the insulating material 24A, as described in relation to Figures 2-5. It will be further recognized that the corresponding structures of the two electrical contact segments may be provided on adjacent electrical contacts, thereby forming an electrical connection between two (or more) individual insulated conductors. The illustrated portions of the circumference traversed by the first and second electrical contact segments 20A1 and 20B1, respectively, merely illustrate the principle of the electrical contact segments.The circumferential portion being traversed is more restricted, providing a certain amount of rotational indexing tolerance, so that when threaded connections are initiated and assembled between adjacent pipe segments, precise rotational alignment may not be required for each electrical contact to accurately engage with each other between adjacent pipe segments.

[0037] Figure 8 shows a diagram of a conductor and corresponding electrical contact segments without emphasis on the elastomer insulating material. Figure 9 shows exemplary embodiments of the first conductor 20A and the second conductor 20B.

[0038] Corresponding figures for single-conductor implementations of electrical connectors, corresponding to those shown in Figures 6-9, are shown in Figures 10-13, respectively. Such implementations may include a first electrical contact assembly 22, as described with reference to Figure 2, located at the pin end of a pipe segment 12. Figure 10 shows the first electrical contact assembly 22 located at the pin end of a pipe segment 12. Figure 11 shows the first electrical contact assembly 22 separated from the pipe segment 12, where the insulating material 22A and conductor 20 may be observed. Figure 12 shows the first electrical contact assembly 22, with the insulating material 22A not highlighted to highlight the electrical contact 22B and conductor 20. Figure 13 shows only the conductor 20 and contact 22B.

[0039] Figures 14 and 15 show one exemplary embodiment of the conductor 20 and associated electrical contacts 22B. The combination of the conductor 20 and the electrical contact 22B may be formed from a single-length conductor having insulating material removed over a predetermined length from the end of the conductor, where the transition from the conductor 20 to the electrical contact 22B is provided by a bend 20E where the conductor 20 passes through the insulating material 22A. To facilitate the molding of the conductor 20 as shown in Figure 14, the conductor 20 may include one or more bending stiffness reduction features. Figure 15 shows an exemplary implementation of such bending stiffness reduction features, where the conductor 20 may include one or more grooves 20F on its outer surface.

[0040] In Figure 16, the end 20G of the conductor 20 adjacent to the bend 20E may include an axial strain relief section to provide the conductor 20 having the ability to extend axially without axial deformation. Figure 17 shows an example of such a strain relief section 20H in the form of a bend or coil. By providing such a strain relief section 20H, the assembled pipe according to this disclosure may reduce the possibility of damage to the conductor 20 when the assembled pipe is subjected to considerable axial elongation or compression during use. As will be recognized by those skilled in the art, such axial elongation increases in the direction of the surface end of the assembled well pipe as the assembled well pipe extends deeper into the well due to the suspending weight of the assembled well pipe.

[0041] Figure 18 shows a partially enlarged view of an exemplary embodiment of a pipe segment and electrical contact assembly according to the present disclosure, having multiple insulating conductors and associated electrical contacts, which are useful, for example, in multiphase power transmission. The pin end of the pipe segment 12, which may be configured as previously described with reference to Figure 1, may include an internal thread 12B and an external thread 12A, also as described with reference to Figure 1. The first electrical contact assembly may include an elastomer insulating material disposed within a receiving feature l located between the internal thread 12B and the external thread 12A. The first conductor 120 and the second conductor 122 may extend, respectively, into holes (see 12C1 and 12C2 in Figure 19) along the length of the pipe segment 12 and may terminate at the respective electrical contacts 120A and 122A. The respective electrical contacts 120A and 122A may traverse only a portion of the circumference of the elastomer insulating material 122A, i.e., a circumferential segment. The two electrical contacts 120A and 122A are shown to be separated at an angle of approximately 180 degrees and have a circumferential range of approximately 90 degrees, but the angular separation and circumferential range are not limiting to the scope of the disclosure. In some implementations, the circumferential range and angular separation may be optimized to balance the contact area while assembling ("make up") the pipe segments together and to reduce the need for a specific rotational direction of each pipe segment thread. The exemplary angular separation described above is not limiting to the scope of the disclosure. The corresponding conductors 140 and 142 may be provided in a casing collar 14 having two or more through-holes (26 in Figure 1), although configured as described with reference to Figure 1, for example, each through-hole may be occupied by one of the corresponding conductors 140 and 142. Each conductor 140 and 142 may terminate with the corresponding electrical contacts 140A and 142A. The electrical contacts 120A and 122A on the pin ends are biased to contact the electrical contacts 140A and 142A on the collar 14.By appropriately positioning the circumferential locations of each electrical contact and appropriately selecting their circumferential ranges, assembly of the pin ends to the collar 14 may be facilitated, while precise galvanic contacts may be formed only between corresponding pairs of electrical contacts, for example, contact 120A mating with contact 140A and contact 122A mating with contact 142A. Although this exemplary embodiment is described with reference to two conductors and associated electrical contacts, it will be recognized that more or fewer conductors and associated electrical contacts in any well pipe are within the scope of this disclosure.

[0042] The enlarged section of Figure 18 also shows the conductors 120, 122, 140, 142 and their respective electrical contacts 120A, 122A, 140A, 142A, 142A, detached from their assembled positions on the pipe segment 12 and collar 14, particularly for the purpose of showing the electrical contacts. The usual positions of the conductors 120, 122, 140, 142 and their respective electrical contacts 120A, 122A, 140A, 142A are the same as those shown in and described with reference to Figure 1.

[0043] Figure 19 shows a perspective view of the pin end segment shown in the side perspective view in Figure 18, and in particular shows the possible positions of the two through holes or channels 12C1 and 12C2.

[0044] Figure 20 shows an end view of the box end segment of Figure 18, which is shown in the side perspective view of Figure 18. The circumferential separation of the two contacts 140A and 142A is shown in particular in Figure 20.

[0045] The wired well pipes described herein may offer better conductivity and reduce the risk of insulation failure associated with wired well pipes known prior to this disclosure.

[0046] In light of the principles and exemplary practices described and illustrated herein, it will be recognized that exemplary practices can be modified in arrangement and detail without departing from such principles. While the preceding discussion has focused on specific practices, other configurations are also contemplated. In particular, where expressions such as “practice” are used herein, these phrases are intended to refer to the possibility of practice in general and are not intended to limit this disclosure to any particular practice configuration. Where used herein, these terms may refer to the same or different practices that can be combined with other practices. In principle, any practice referenced herein may be freely combined with any one or more other practices referenced herein unless otherwise indicated, and any number of features of any different practices may be combined with one another. While only a few examples have been described in detail above, those skilled in the art will readily recognize that many modifications are possible within the scope of the examples described. Accordingly, all such modifications are intended to be included within the scope of this disclosure as defined in the following claims.

Claims

1. A well pipe having a conductive material, At least one pipe segment having a hole or channel extending along the length of the pipe segment between a first threaded connection at one longitudinal end of the at least one pipe segment and a second threaded connection at another longitudinal end of the at least one pipe segment, and having at least one insulated conductor extending along the hole or channel, A well pipe comprising a receiving feature disposed in each of the first and second threaded connections for receiving an electrical contact assembly, wherein the electrical contact assembly comprises an insulating material having a retaining feature for arranging at least one electrical contact internally, the at least one electrical contact being electrically connected to the at least one insulated conductor, where at least a portion of the at least one electrical contact is exposed from the retaining feature.

2. The well pipe according to claim 1, wherein the surface angle of the insulating material is oblique, or the radius of curvature defined by the electrical contact of the first screw connection is different from the radius of curvature defined by the electrical contact of the second screw connection, or the retaining feature defines a circular cross-sectional groove that crosses more than 180 degrees of the circumference around the electrical contact located inside.

3. The well pipe according to claim 2, wherein the insulating material includes a longitudinal extension protruding from one side of the surface of the insulating material.

4. The well pipe according to claim 3, wherein the longitudinal extension includes a taper.

5. The well pipe according to claim 1, wherein the first threaded connector and the second threaded connector each include a male threaded connector.

6. The present invention further includes at least one pipe connector having a female threaded connection at each longitudinal end, wherein each female threaded connection of the at least one pipe connector includes a receiving feature for receiving an electrical contact assembly. Each female threaded connector's electrical contact assembly includes an insulating material having a retaining feature for arranging at least one electrical contact internally, the at least one electrical contact being electrically connected to at least one insulated conductor located in a hole extending between the female threaded connectors at each longitudinal end. Here, in one or both electrical contact assemblies, at least a portion of the at least one electrical contact is exposed from the retaining feature. The well pipe according to claim 5.

7. The well pipe according to claim 6, wherein in the at least one pipe connector, (i) the surface angle of the insulating material is oblique, (ii) the radius of curvature defined by the electrical contacts of the threaded connection is different from the radius of curvature defined by the electrical contacts of at least one threaded connection of the pipe segment, or (iii) the retaining feature defines a circular cross-sectional groove that traverses more than 180 degrees of the circumference around the electrical contacts located inside.

8. The retaining feature for receiving the electrical contact assembly of at least one pipe connector cooperates with the receiving feature of either the first threaded connection or the second threaded connection of the at least one pipe segment to form a pressure isolation chamber. The well pipe according to claim 6, wherein the electrical contact assembly of the female screw connection and the electrical contact assembly of the first screw connection or the second screw connection of at least one segment of the pipe are arranged in the chamber when the first screw connection or the second screw connection is assembled with respect to the female screw connection.

9. The well pipe according to claim 6, wherein the feature for receiving the electrical contacts of the female threaded connection includes an expanded space for the insulating material.

10. The well pipe according to claim 6, wherein the at least one pipe connector includes a casing collar.

11. The well pipe according to claim 1, wherein the features disposed in the first screw connection and the second screw connection for receiving electrical contacts include an expanded space for the insulating material.

12. The assembly of the first threaded connection to a corresponding threaded connection on an adjacent pipe segment or pipe connector defines a chamber isolated from fluid pressure from outside and inside the well pipe by forming a metal-to-metal seal, according to claim 1.

13. The well pipe according to claim 1, wherein the insulating material includes an elastomer.

14. The well pipe according to claim 1, wherein the electrical contacts are held within the retaining feature by an adhesive.

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