This disclosure is an alteration and improvement on U.S. Pat. No. 10,612,318, to Darren Wall et al., entitled Inductive Coupler Assembly for Downhole Transmission Line, issued Apr. 7, 2020. The background, prior art figures, and related descriptions herein were taken from said patent.
Further, U.S. Pat. No. 11,033,958, to Imaoka, et al., entitled Magnetic Material and Manufacturing Method Therefore, issued Jun. 15, 2021, is incorporated into this application by this reference for all that it teaches and claims.
In downhole drilling operations, downhole measuring tools are used to gather information about geological formations, status of downhole tools, and other downhole conditions. Such data is useful to drilling operators, geologists, engineers, and other personnel located at the surface. This data may be used to adjust drilling parameters, such as drilling direction, penetration speed, and the like, to effectively tap into an oil or gas bearing reservoir. Data may be gathered at various points along the drill string, such as from a bottom-hole assembly or from sensors distributed along the drill string. Once gathered, apparatus and methods are needed to rapidly and reliably transmit the data to the surface. Traditionally, mud pulse telemetry has been used to transmit data to the surface. However, mud pulse telemetry is characterized by a very slow data transmission rate (typically in a range of 1-6 bits/second) and is therefore inadequate for transmitting large quantities of data in real time. Other telemetry systems, such as wired pipe telemetry system and wireless telemetry system, have been or are being developed to achieve a much higher transmission rate than possible with the mud pulse telemetry system.
In wired pipe telemetry systems, inductive couplers or transducers are provided at the ends of wired pipes. The inductive transducers at the opposing ends of each wired pipe are electrically connected by an electrical conductor running along the length of the wired pipe. Data transmission involves transmitting an electrical signal through an electrical conductor in a first wired pipe, converting the electrical signal to a magnetic field upon leaving the first wired pipe using an inductive transducer at an end of the first wired pipe, and converting the magnetic field back into an electrical signal using an inductive transducer at an end of the second wired pipe. Several wired pipes are typically needed for data transmission between the downhole location and the surface.
While downhole, a wired pipe string is subjected to high loads and harsh conditions which can adversely affect the life and function of inductive couplers. In addition, stray magnetic fields may affect inductive transducers by introducing additional inductances to the coupler, which can alter the performance of the coupler. Stray fields can also extend into unsuitable materials and result in increased losses. Stray magnetic fields can produce an increase in attenuation and a decrease in effective bandwidths. Variations in attenuation and bandwidth can cause problems in producing a reliable telemetry rate.
Premium drill pipe joints may rely on external shoulders adjacent the threaded portions of the drill pipe's pin and box ends to produce the torque required to make up a drill string. An annular groove may be formed in the mating shoulders of the drill pipe and serve as a housing for an annular polymeric block. The annular polymeric block may comprise an inductive coupler assembly molded therein comprising a magnetically conductive electrically insulating (MCEI) ferrite ring. The ferrite ring may comprise a continuous ring of ferrite material or it may be made of two or more ring segments. Ring segments may be preferred because of the brittle nature of ferrite. The ferrite ring may comprise a top surface that is exposed on the top surface of the polymeric block. The exposed top surface of the ferrite ring may promote magnetic coupling between opposed ferrite rings when pipe joints are made up. The ferrite ring may comprise an annular interior channel in which a conductive wire coil having one or more turns may run along the annular interior channel producing an inductive coupler suitable for transmitting data and power across the drill pipe joints of the made-up drill string. Although the inductively coupled joint may effectively allow the transmission of a power or data signal across interconnected joints, the respective signals may experience losses due to stray magnetic fields and the proximity of conductive metals in the drill pipe, themselves.
The polymeric block comprising MCEI components may reduce the signal losses in the coupled drill pipe. The polymeric block may comprise a polymer such as polyether ether ketone (PEEK), polytetrafluoroethylene (PTFE) (Teflon), or Polyoxymethylene (Delrin), or a combination thereof. Other polymers, resins, or epoxies also may be a suitable block material. A volume of micron (mμ) and submicron (nm) size MCEI particles, such as Fe and Mn based ferrite elements may be mixed into the polymeric block along with the ferrite ring during manufacture. The presence of the ferrite ring and the MCEI particles may reduce data and signal losses across the drill pipe connection.
The annular block may be configured with a planar top surface exposed on the top of the polymeric block, a curved bottom surface, and the respective surfaces may be joined by inside and outside peripheral side surfaces, housing the ferrite ring.
The outside (largest diameter) peripheral side surface of the polymeric block may comprise a protruding bumper molded into the polymer. The bumper may be aligned with a bumper seat formed in the wall of the shoulder groove adjacent the block when the block is installed into the annular groove. The polymeric block may comprise a discrete bumper at a selected orientation around the circumference of the block, or there may be two or more bumpers positioned around the circumference of the block. Two or more seats also may be formed in the wall of the annular groove housing the block. In some configurations, it may be preferred to form a continuous bumper around the circumference of the block. In which case, the bumper seat may be a circumferential seat in the wall of the annular groove.
The annular polymeric block may further comprise a gasket comprising an axial pathway through which a portion of the conductive wire may pass as the conductive wire exits the annular block and travels through an opening in the drill pipe shoulder material. The gasket may be formed into the block when the block is manufactured. A portion of the gasket may extend outside the block and mate with a gasket seat in the bottom of the annular groove. The gasket may form a pressure and fluid seal protecting the block from the downhole environment. Alternatively, the gasket may extend from the bottom of the annular interior channel in the ferrite ring through the ferrite ring, the bottom of the block, the groove, and into the drill pipe shoulder, the gasket and wire extending to a point where the conductive wire intersects the cable running the length of the drill pipe.
The polymeric block may comprise PEEK, PTFE, Delrin, or other suitable materials comprising MCEI elements of Fe and Mn ranging in average sizes from about 3 nm to about 1250 mμ. Or the polymeric block may comprise a combination of the various polymers, resins, epoxies, and other suitable materials comprising MCEI elements ranging in average sizes from about 3 nm to about 1250 mμ. The MCEI elements useful in the polymeric block may comprise transition metals as identified in the periodic table, including their mixtures, alloys and oxides. Elements that form divergent bonds with Fe and Mn may also be useful in reducing the signal losses across the drill pipe connections.
The volume of MCEI elements to polymer in the annular polymeric block may comprise an average of between 3% and 65% by volume of the polymer comprising the annular block.
The combination of Fe and Mn within the MCEI elements within the polymer comprising the annular polymeric block may comprise an average ratio of between 2 to 8 and between 8 to 2, respectively. The combination of Fe and Mn within the MCEI elements within the polymer comprising the annular block may comprise an average ratio of between 2 to 6 and between 6 to 2, respectively. Or the combination of Fe and Mn within the MCEI elements within the polymeric block may comprise an average ratio between 4 to 6 and between 6 to 4, respectively. Or the combination of Fe and Mn within the MCEI elements within the polymer comprising the annular block may comprise an average ratio between 6 to 8 and between 8 to 6, respectively. Also, the combination of Fe and Mn within the MCEI elements within the polymer comprising the annular block comprises an average ratio between 8 to 4 and between 4 to 8, respectively. Alternatively, the combination of Fe and Mn within the MCEI elements within the polymer comprising the annular block comprises an average ratio 1 to 1. A variety of mixtures may be desirable because as the length of the drill string increases, the signal tends to be attenuated across the many joints.
The annular polymeric block may further comprise at least one void opening encapsulated inside the block adjacent the peripheral sides and bottom surfaces. The void openings may promote resiliency in the block. As the block is pressed into the annular groove, a void opening adjacent the bumper may allow the bumper to collapse until it is allowed to expand into the bumper seat removably capturing the block in the groove. Also, the presence of the void openings within the block may allow the block to absorb the compressive forces on the respective shoulders incident to joint make up thereby protecting the ferrite ring inside the block. The bumper may comprise an anterior dimple in its exterior surface. The dimple may further add resilience to the bumper.
The following discussion is directed to
Certain terms are used throughout the following description and claim to refer to particular system components. This document does not intend to distinguish between components that differ in name but not function. Moreover, the drawing figures are not necessarily to scale. Certain features of the disclosure may be shown exaggerated in scale or in somewhat schematic form, and some details of conventional elements may not be shown in the interest of clarity and conciseness.
In the following discussion and in the claims, the terms “including” and “comprising” are used in an open-ended fashion, and thus should be interpreted to mean “including, but not limited to . . . .” Also, the term “couple” or “couples” is intended to mean either an indirect or direct connection. Thus, if a first device couples to a second device, that connection may be through a direct connection, or through an indirect connection via other devices, components, and connections. In addition, as used herein, the terms “axial” and “axially” generally mean along or parallel to a central axis (e.g., central axis of a body or a port), while the terms “radial” and “radially” generally mean perpendicular to the central axis. For instance, an axial distance refers to a distance measured along or parallel to the central axis, and a radial distance means a distance measured perpendicular to the central axis. Still further, reference to “up” or “down” may be made for purposes of description with “up,” “upper,” “upward,” or “above” meaning generally toward or closer to the surface of the earth or the beginning of the drill string as the orientation of the drill string elements relative to the earth's surface changes during horizontal drilling, and with “down,” “lower,” “lower end,” “downward,” or “below” meaning generally away or further from the surface of the earth or toward the bit end (i.e., the distal end of the drill string) as the orientation of the drill string elements relative to the earth's surface changes during horizontal drilling.
Referring to
Referring to
The polymeric block (1005) comprising MCEI components may reduce the signal losses in the coupled drill pipe. The polymeric block (1005) may comprise a polymer such as polyether ether ketone (PEEK), polytetrafluoroethylene (PTFE) (Teflon), or Polyoxymethylene (Delrin), or a combination thereof. Other polymers, resins, or epoxies also may be a suitable material for block (1005). A volume of micron (mμ) and submicron (nm) size MCEI particles comprising Fe and Mn based ferrite elements may be mixed into the polymeric block (1005) along with ferrite ring (1030) during manufacture. The presence of the ferrite ring (1030) and the MCEI particles may reduce data and signal losses across the drill pipe connection.
The annular block (1005) may be configured with a planar top surface, a curved bottom surface (1060), and the respective surfaces may be joined by inside (1020) and outside (1035) peripheral side surfaces, housing the ferrite ring (1030).
The outside (1035) (largest diameter) peripheral side surface of the polymeric block (1005) may comprise a protruding bumper (1040) molded into the polymer. The bumper (1040) may be aligned with a bumper seat (1095) formed in the wall of the shoulder groove adjacent the block (1005) when the block (1005) is installed into the annular groove (1015). The polymeric block (1005) may comprise a discrete bumper (1040) at a selected orientation around the circumference of the block (1005), or there may be two or more bumpers (1040) positioned around the circumference of the block (1005). Two or more seats (1095) also may be formed in the wall (1035) of the annular groove (1015) housing the block (1005). In some configurations, it may be preferred to form a continuous bumper (1040) around the circumference of the block (1005). In which case, the bumper seat (1095) may be a circumferential seat in the wall (1035) of the annular groove (1015).
The annular block (1005) may further comprise a gasket (1070) comprising an axial pathway through which a portion of the conductive wire (1065) may pass as the conductive wire exits the annular block (1005) and travels through an opening in the drill pipe shoulder material. The gasket (1070) may be formed into the block (1005) when the block (1005) is manufactured. The gasket (1070) may comprise a flange or collar (1080) to further secure the gasket (1070) inside the polymeric block (1005). A portion of the gasket may extend outside the block (1005) and mate with a gasket seat (955) in the bottom of the annular groove. The gasket may form a pressure and fluid seal protecting the block (1005) from the downhole environment. Alternatively, the gasket (1090) may extend from the bottom of the annular interior channel (1090) in the ferrite ring through the ferrite ring (1030), the bottom (1050) of the block (1005), the groove (1015), and into the drill pipe shoulder (1001) below the groove, the gasket (1090) and wire (1065) extending to a point where the conductive wire (1065) intersects the cable running the length of the drill pipe.
The polymeric block (1005) may comprise PEEK, PTFE, Delrin, or other suitable materials comprising MCEI elements of Fe and Mn ranging in average sizes from about 3 nm to about 1250 mμ. Or the polymeric block (1005) may comprise a combination of the various polymers, resins, epoxies, and other suitable materials comprising MCEI elements ranging in average sizes from about 3 nm to about 1250 mμ. The MCEI elements useful in the polymeric block (1005) may comprise transition metals as identified in the periodic table, including their alloys and oxides. Elements that form divergent bonds with Fe and Mn may also be useful in reducing the signal losses across the drill pipe connections.
The volume of MCEI elements to polymer in the annular polymeric block (1005) may comprise an average of between 3% and 65% by volume of the polymer comprising the annular block (1005).
The combination of Fe and Mn within the MCEI elements within the polymer comprising the annular polymeric block (1005) may comprise an average ratio of between 2 to 8 and between 8 to 2, respectively. The combination of Fe and Mn within the MCEI elements within the polymer comprising the annular block (1005) may comprise an average ratio of between 2 to 6 and between 6 to 2, respectively. Or the combination of Fe and Mn within the MCEI elements within the polymeric block (1005) may comprise an average ratio between 4 to 6 and between 6 to 4, respectively. Or the combination of Fe and Mn within the MCEI elements within the polymer comprising the annular block (1005) may comprise an average ratio between 6 to 8 and between 8 to 6, respectively. Also, the combination of Fe and Mn within the MCEI elements within the polymer comprising the annular block (1005) comprises an average ratio between 8 to 4 and between 4 to 8, respectively. Alternatively, the combination of Fe and Mn within the MCEI elements within the polymer comprising the annular block (1005) comprises an average ratio 1 to 1.
The annular polymeric block (1005) may further comprise at least one void opening (1045) encapsulated inside the block (1005) adjacent the peripheral sides (1020, 1035) and bottom surfaces (1060). The void openings (1045) may promote resiliency in the block (1005). As the block (1005) is pressed into the annular groove 1015), a void opening (1045) adjacent the bumper (1040) may allow the bumper to collapse until it is allowed to expand into the bumper seat (1095) removably capturing the block (1005) in the groove (1015). Also, the presence of the void openings 1045) within the block (1005) may allow the block (1005) to absorb the compressive forces on the respective shoulders (1001) incident to joint make up thereby protecting the ferrite ring (1030) inside the block (1005). The bumper may comprise an anterior dimple (1085) in its exterior surface. The dimple may further add resilience to the bumper (1040).
Referring further to
When the drill pipe has a primary and secondary shoulder in its joint, the circular groove may be in either shoulder. See U.S. Pat. No. 6,821,147, to Hall et al., entitled Internal Coaxial Cable Seal System, issued Nov. 23, 2004, incorporated herein by this reference for all it teaches and claims. The respective shoulders are circumferential and located either before or after the threads of the joint. When two drill pipes are made up, i.e., screwed together, the pipe's pin end is screwed into the opposing pipe's box end. The pipes are torqued together sufficiently that the shoulders produce a fluid tight seal preventing the passage of downhole fluids from escaping or entering the bore of the drill pipe. The shoulder seals also prevent pressure loss both between the formation borehole and the pipe bore.
The inductive coupler assembly comprises a ferrite circular channel (945) arranged around the interior of the block (910). The ferrite forms the sides and bottom of the channel (945). The ferrite channel's top side (915) may be fully open, free of the lining, or partially closed by the ferrite. The ferrite channel's top side (915) may intersect the top surface of the block (910), or it may be fully enclosed within the block (910). The ferrite channel (945) may be a discrete ferrite ring or a series of ferrite segments forming the channel (945). The ends of the ferrite segments may be configured to tightly mate with each other. The ferrite segments may be arranged end for end forming a gap-free channel (945). The ferrite channel's top surface (915) may comprise a polished surface along its open or partially open side.
At least one turn of a conductive wire (950) may be disposed within the ferrite channel (945). The conductive wire (950) turns may form a coil that when energized may produce an electromagnetic field that may be directed by the ferrite channel (945) toward an opposed inductive coupler of a mating drill pipe joint. See prior art
The annular block (910) may comprise one or more bumpers (935) formed therein disposed around the outside periphery of the annular block (910) in the annular block's (910) side walls (970 and 970a) respectively. The bumper (935) may be continuous around the annular block's periphery, or it may comprise one or more discrete bumpers (935) spaced intermittently around the periphery of block (910). The bumper (935) may comprise a side wall that may extend diagonally from the outermost edge of the bumper (935) downward to the side surface (970 and 970a) of the block (910). The bumper (935) may comprise an opening (975) for added compliancy when the block (910) is installed or removed. In the shoulder (905), the external side wall (990a) is the sidewall of the groove (990) radially farthest from the pipe's internal bore (see prior art
The block (910) may comprise one or more internal void openings (940, 940a) adjacent its side surfaces. Void openings (940, 940a) may be circular or elongate. Void opening (940) may be disposed proximate the bumper (935). The void openings (940, 940a) may promote compliancy in the block. The void opening (940) allows the bumper (935) to flex as the block is press fit into the groove (990) and is removed from the groove (990). Once the bumper (935) enters the recess (930) in the groove's side wall (990a), the bumper is allowed to spring back so that the block (910) is at least partially secured in the groove. The internal void openings 940, 940a) may form a continuous ring around the interior of the block. Or the void openings may be discrete openings intermittently arranged such that a plurality of void openings (940, 940a) may be positioned around the interior circumference of the block. A void opening (940a) may be located adjacent the curved bottom surface (980) of the block (910) and may permit the block (910) to move vertically or compress in the event debris remains on the top surface of the block (910) when the joint is made up. Also, compliancy in the block provided by the void openings may protect the block (910) in the event the shoulder (905, 920) is damaged in the makeup process or compressed or deformed by an over-torqued drill pipe joint.
The block (910) further may comprise an internal annular gasket (960) that may comprise a collar portion (995) partially extending from the bottom surface (980) of the block. The internal gasket (960) may be molded into the block (910) when it is first formed with the other coupler elements. The external portion of the gasket (960) may be formed to fit within a mating gasket seat (955) in the bottom (985) of the groove. The wire (950) may pass through an opening in the center of the gasket (960) as an exit path for the wire (950) from the block (910). When the block (910) is installed into the groove (990), the gasket (960) may be pressed into the gasket seat (995), the gasket (960) may seal the wire (950) and the annular block (910) from the downhole environment. The external portion of the gasket (960) may comprise ribs (not shown) to aid in the sealing of the block. The collar (995) may provide stability for the gasket (960) within the block (910) and aid in its sealing function. The gasket (960) may serve as an aid for the seal set (see Prior Art
The block (910) may further comprise an electromagnetic shield (965) enclosing the sides and bottom of the ferrite (945). The shield may be composed of a magnetically conductive electrical insulating material. The shield may aid in focusing the magnetic field and preventing stray electromagnetic interference with the block (910).
Prior art
The drill string 13 preferably includes a plurality of network nodes 30. The nodes 30 are provided at desired intervals along the drill string. Network nodes essentially function as signal repeaters to regenerate data signals and mitigate signal attenuation as data is transmitted up and down the drill string. The nodes 30 may be integrated into an existing section of drill pipe or a downhole tool along the drill string. Sensor package 38 in the BHA 15 may also include a network node (not shown separately). For purposes of this disclosure, the term “sensors” is understood to comprise sources (to emit/transmit energy/signals), receivers (to receive/detect energy/signals), and transducers (to operate as either source/receiver). Connectors 34 represent drill pipe joint connectors, while the connectors 32 connect a node 30 to an upper and lower drill pipe joint. As is standard in the art, each section of drill pipe 12 has a box joint at one end and a pin joint at the opposite end. Further, each pipe joint has a coupler having a core of magnetic material that transfers signals from one drill pipe 12 to the next. When the pipe joint is made up, the cores transfer the magnetic field from one side to the other. When a coil on one side receives an applied signal, it generates a magnetic field. The core transfers the magnetic field to the other coil which generates an induced signal. One of the factors affecting the efficiency of transfer of the signal is the existence of any stray fields that exist outside of the core magnetic material on each side of the pipe joint and extend out into the pipe. The existence of a gap also introduces stray magnetic fields. These stray magnetic fields contribute to the losses produced in the inductive coupler. These stray magnetic fields can be reduced with careful shaping of the core of the inductive coupler.
This disclosure describes an assembly and a method for controlling the stray magnetic fields of an inductive coupler to reduce the associated losses. This results in reduced attenuation (increased efficiency) of the inductive coupler even in the presence of gaps. The stray magnetic fields that extend outside the inductive coupler and into the surrounding drill pipe result in losses due to induced currents and subsequent resistive heating. The extent at which the fields extend outside the core depends on the material properties of the outside material and the frequency.
The depth of penetration is called the skin depth and has the form delta..omega..mu..times..times..sigma. ## EQU00001## where .delta. is the skin depth, .omega. is the circular frequency and .sigma. is the conductivity. The amplitude of the electric field is proportional to the magnetic field H by the form .omega..times..pi..times..mu..sigma..times. ## EQU00002##. The electric field can be reduced by having a permeability of 1 and a conductivity as high as possible. Reducing the skin depth can also reduce the amount of resistive heating; for example, with a large permeability and a high conductivity. The electric field in penetrating into the pipe would start with the amplitude of the electric field (E) and decay following the skin depth (.delta.). The desire is to reduce the power dissipated in the surrounding material. The power density dissipated by this electric field is P=.sigma.E.sup.2 Substituting in equations for the skin depth (.delta.), the amplitude of the electric field (E), and the power density (P), and multiplying by the volume where the E field decays (A.delta.) gives the power dissipated in terms of permeability and conductivity. Combining constants and parameters so that permeability and conductivity are clear gives .times..omega..mu..sigma..times..times..times..omega..mu..sigma. ## EQU00003## The exponential term contains the skin depth. Increasing the permeability reduces the depth penetration and increases the amplitude of the electric field. For materials representing pipe steel, copper, and a magnetic core material (high permeability and conductivity) at 2 MHz, the power dissipated in the pipe is greater than for the copper. Further, the magnetic core material has a high permeability for a small skin depth and a conductivity intermediate to that of the copper and pipe steel. While the high permeability yields a small skin depth, the conductivity is not high enough to compensate for the increased amplitude and so more power is dissipated than the copper.
Referring still to prior art
A plurality of packets may be used to transmit information along the nodes 30. Packets may be used to carry data from tools or sensors located downhole to an uphole node 30, or may carry information or data necessary to operate the network 46. Other packets may be used to send control signals from the top node 30 to tools or sensors located at various downhole positions.
Referring to prior art
Referring to prior art
Anti-rotation pin 113 is generally T-shaped, and comprises a rectangular horizontal portion 113H disposed at the bottom of housing interior channel 110d and a cylindrical vertical portion 113V disposed orthogonal to horizontal portion 113H. The anti-rotation pin 113 further comprises a throughbore 113a that extends axially downward through both the horizontal and vertical portions 113H, 113V, respectively. Further, throughbore 113a is coaxial with throughbore 112a of anti-rotation boss 112 and anti-rotation pin 113 is sized to fit within boss 112, such that pin 113 insulates wire 130 from the housing 110 (shown in prior art
Referring now to prior art
Ferrites 118 are disposed end-to-end in housing interior channel 110d between spacers 116, such that ferrites 118 are disposed in substantially the entire interior channel 110d. Ferrites 118 may be made of any suitable material containing a magnetic field known in the art, including but not limited to 61 NIZN made by Fair-Rite Corp., Co-Nectic AA made by Magnetic Shield Corp., and Fluxtrol made by Fluxtrol Corp. Similar to the spacers 116, each ferrite 118 comprises a channel 118a through which wire 130 is disposed. Thus, wire 130 passes through and rests in the channel 116a of each spacer 116, passes through and rests in the channel 118a of each ferrite 118, and then passes through the throughbore 113a in anti-rotation pin 113 along with throughbore 112a of anti-rotation boss 112, and on to a coaxial data cable embedded in the tool joint of drill string 12.
Referring now to prior art
Referring now to prior art
Referring now to prior art
Referring now to prior art
Referring now to prior art
Referring still to prior art
Referring now to prior art
Referring now to prior art
Seal stack 140 sealingly engages armored coax tubing or data cable tubing 180, which extends above seal stack 140 to also interface with grounding tube 150. Data cable tubing 180 may be made of any suitable material known in the art, including but not limited to metals. The interface between the grounding tube 150 and the data cable tubing 180 provides a robust ground path. In addition, tapered portion 175, disposed below seal stack 140, comprises a tapered end that wedges into the data cable tubing 180 to provide a backup for the seal stack 140. Tapered portion 175 may be made of any suitable material known in the art, including but not limited to ceramics and polymers. For example, tapered portion 175 may be made of ceramic flarel. Further, seal stack 140 and angled back up 154 may be removed and replaced when housing 110 is removed.
Referring to prior art
In the present embodiment, the shoulder 205a is machined and located at the precise location needed to properly position the coupler 280 and bushing 210 is inserted all the way to the shoulder 205a, such that bushing lower end 210d is in contact with shoulder 205a of the bore. In another embodiment, shown in prior art
Referring now to prior art
Housing 250 for coupler 280 is cylindrical, has an upward-facing channel or U-shaped cross section 250a with two extensions or legs 250b extending axially downward from the bottom of the channel 250a. Housing 250 may be made of any suitable material known in the art, including but not limited to metals. The extensions 250b are welded onto the retention pin inner cylindrical surface 230d near upper end 230a of retention pin 230. Thus, the removal of coupler 280 would also remove the three retention pins 230 welded to the housing 250. In alternative embodiments, the retention pins 230 may be stamped or machined as part of the housing 250.
Referring still to prior art
As previously discussed, electrical contact 270 snaps over and into the second or middle channel 235. Electrical contact 270 may be made of any suitable material known in the art. Electrical contact 270 utilizes the retention pin 230 as part of the grounding path, removing the need to have a grounding tube as in the first embodiment of a removable induction coupler system 100. The ground path would thus go from the coupler 280 to the retention pin 230, out into the pipe 12, and then through the pipe to the data cable (not shown).
After the electrical contact 270 is installed on retention pin 230, the retention pin 230 may be installed in the retention bushing 210 by pushing the retention pin 230 into the center of the retention bushing 210 until both the retention spring element 260 and the electrical contact 270 interface with the retention bushing 210.
Referring still to prior art
By moving the retention pin 230 away from the surface of the secondary shoulder 59 (an area subject to deformation) to below the surface of the pin end, the retention features are in a more stable area of the pipe 12 and subject to less deformation. Further, when the coupler 280 is removed, the retention pin 230, retention spring element 260, electrical contact 270, and the seal stack (not shown) are also removed and may be replaced while reusing the coupler 280.
Referring to prior art
The removable pin end induction coupler system 400 shown in prior art
Spring 360 is a continuous ring that goes around the entire pipe 12 circumference below housing 350 and in a shoulder of pipe 12. Spring 360 allows inductive couplers to be brought into contact with adequate force independent of manufacturing and assembly tolerances or subsequent operational deformations. Spring 360 may be made of any suitable material with elastic properties known in the art including, but not limited to, a metallic spring, elastomer, and a spring-loaded portion.
Referring now to prior art
During installation, spring 360 is placed in box end shoulder 58 before the housing 350 is inserted, followed by the retention ring 310, which locks the spring 360 and housing 350 in place. In an alternative embodiment, the spring 360 may be located under housing 350, such that the spring 360 and housing 350 are installed together as an assembly.
Referring still to prior art
Referring to prior art
Housing 450 for coupler 480 is cylindrical, has an upward-facing channel or U-shaped cross section 450a with a bottom face 450b and a side wall 450c. Housing 450 further comprises a ledge or flat ring 455 that is coupled to the bottom face 450b of the housing 450 and extends radially inward past side wall 450c, creating a ledge or shoulder. Housing 450 may be made of any suitable material known in the art, including but not limited to metals. In the present embodiment, ledge or flat ring 455 is welded to the bottom face 450b of housing. In alternative embodiments, ledge 455 may be machined or manufactured directly on the housing 450. In an embodiment, the couplers 380, 480 for the box end and pin end, respectively, are the same. During installation, coupler 480 is placed in pin end shoulder 54 before the retention ring 410 is press fit to lock the coupler 480 in place.
Referring now to prior art
Referring still to prior art
Referring still to prior art
Referring to prior art
Shell 650 is generally cylindrical and has a substantially U-shaped cross section with an external bottom end 650a opposite a top end 650b; cylindrical external side walls 650c, 650d; an internal bottom surface 650e; and cylindrical internal side walls 650f, 650g. Shell 650 is disposed in annular groove 610 such that shell external bottom 650a is in contact with groove bottom 610a, shell cylindrical external side walls 650c, 650d, are in contact with groove inner and outer side walls 610c, 610d, respectively, and shell top end 650b is aligned with groove opening 610b. Shell 650 may be made of any suitable material having an appropriate permeability and conductivity to reduce the power dissipated compared to the surrounding material (discussed in more detail below). For example, shell 650 may be made of copper or beryllium copper.
Referring still to prior art
In the present embodiment, the groove openings 610b, the shell top surfaces 610b, the ferrite ring top ends 618b, and the ferrite ring annular channels 630 of the box end 18 and pin end 19 are aligned and separated by a gap 615. Gap 615 is preferably between 0.003-0.020 inches, and more preferably approximately 0.005 inches. Further, the induction coupler system 600 is symmetrical about joint 620, but need not be.
Referring now to prior art
Referring now to prior art
Referring now to prior art prior art
The amount of power dissipated due to stray magnetic fields is reduced by the presence of a shell. Thus, by selecting an appropriate cladding material for the shell 650, the amount of power dissipated due to the stray magnetic fields can be reduced. As previously described, the material used for shell 650 may be any suitable material having an appropriate permeability and conductivity to reduce the power dissipated compared to the surrounding material. For example, shell 650 may be made of copper or beryllium copper.
Exemplary embodiments are described herein, though one having ordinary skill in the art will recognize that the scope of this disclosure is not limited to the embodiments described, but instead by the full scope of the following claims. The claims listed below are supported by the principles described herein, and by the various features illustrated which may be used in desired combinations.
This application is a continuation-in-part of pending U.S. patent application Ser. No. 17/510,732, filed Oct. 10, 2021, entitled Inductive Coupler For Downhole Transmission Line. The foregoing patent application is incorporated herein by this reference for all that it teaches and claims.