(19) United States
`(12) Patent Application Publication (10) Pub. No.: US 2006/0189208A1
`(43) Pub. Date:
`Aug. 24, 2006
`Shaikh
`
`US 2006O189208A1
`
`APPARATUS AND METHODS FOR SEALNG
`A HIGH PRESSURE CONNECTOR
`
`(52) U.S. Cl. .............................................................. 439/589
`
`(57)
`
`ABSTRACT
`
`An electrical connector for use in downhole environment
`and methods for use are provided. In one aspect, an electrical
`connector comprises a Substantially cylindrical connector
`body having a first end and a second end. A groove is formed
`around an outer surface of the connector body wherein the
`groove has a first Substantially conically beveled Surface on
`a side of the groove proximate the second end. A back-up
`ring has a second Substantially conically beveled Surface and
`is adapted to act cooperatively with an elastomer seal to
`close an extrusion gap between the connector body and a
`Surrounding Surface when the elastomer seal is exposed to a
`positive differential pressure from the first end to the second
`end. In another aspect, a conical Surface on the connector
`body is forced to engage a mating Surface on a bulkhead,
`thereby forming a metal to metal seal.
`
`AG Press
`19
`
`(54)
`
`(75)
`
`(73)
`
`(21)
`(22)
`
`Inventor: Farhat Shaikh, Houston, TX (US)
`Correspondence Address:
`MADAN, MOSSMAN & SRIRAM, P.C.
`2603 AUGUSTA
`SUTE 700
`HOUSTON, TX 77057 (US)
`Assignee: Baker Hughes Incorporated, Houston,
`TX (US)
`Appl. No.:
`11/062,383
`
`Filed:
`
`Feb. 22, 2005
`
`Publication Classification
`
`(51)
`
`Int. C.
`HOIR 3/40
`
`(2006.01)
`
`
`
`SWM and NexTier Ex. 1034 – Page 1
`SWM and NexTier v. DynaEnergetics
`PGR2021-00097 – U.S. Patent No. 10,844,697
`
`

`

`Patent Application Publication Aug. 24, 2006 Sheet 1 of 4
`
`US 2006/0189208A1
`
`
`
`SWM and NexTier Ex. 1034 – Page 2
`SWM and NexTier v. DynaEnergetics
`PGR2021-00097 – U.S. Patent No. 10,844,697
`
`

`

`Patent Application Publication Aug. 24, 2006 Sheet 2 of 4
`
`US 2006/0189208A1
`
`ZIN
`/
`
`14
`
`IV\
`G.G.
`
`
`
`.
`.' ' ". .
`. .
`.
`.
`.
`.
`“w
`SxSXSy
`
`as
`
`ul
`
`
`
`(I
`
`
`
`SWM and NexTier Ex. 1034 – Page 3
`SWM and NexTier v. DynaEnergetics
`PGR2021-00097 – U.S. Patent No. 10,844,697
`
`

`

`Patent Application Publication Aug. 24, 2006 Sheet 3 of 4
`
`US 2006/0189208A1
`
`
`
`SWM and NexTier Ex. 1034 – Page 4
`SWM and NexTier v. DynaEnergetics
`PGR2021-00097 – U.S. Patent No. 10,844,697
`
`

`

`Patent Application Publication Aug. 24, 2006 Sheet 4 of 4
`
`US 2006/0189208A1
`
`
`
`A '91+
`
`SWM and NexTier Ex. 1034 – Page 5
`SWM and NexTier v. DynaEnergetics
`PGR2021-00097 – U.S. Patent No. 10,844,697
`
`

`

`US 2006/0189208 A1
`
`Aug. 24, 2006
`
`APPARATUS AND METHODS FOR SEALING A
`HGH PRESSURE CONNECTOR
`
`BACKGROUND OF THE INVENTION
`0001) 1. Field of the Invention
`0002 The present invention pertains to energy connec
`tors and more particularly to connectors for high pressure
`environments.
`0003 2. Related Prior Art
`0004 Tools used in drilling, logging, and producing oil
`wells commonly consist of various electronic instruments
`and circuits contained at atmospheric pressure within one or
`more pressure housings in the downhole tools. The Sur
`rounding downhole environment may exhibit pressures up
`to 30,000 psi at temperatures up to 500 F. The electronics
`inside the pressure housings require a hermetic type elec
`trical connector that interconnects the electrical circuits in
`the separate housings and/or with electrical conductors in a
`wireline to maintain communications with electronic instru
`ments at the Surface. The connectors must easily connect and
`disconnect and function as electrical conductors in extreme
`hostile liquid environments such as brine, oil base drilling
`mud and fluids that may contain hydrogen sulfide, carbon
`dioxide, methane, and other elements at the extreme down
`hole ambient conditions. The connectors may carry Substan
`tial amounts of power with signals of several hundred volts
`being common.
`0005. A typical single pin type connector to which
`aspects of the invention pertain includes a conductive pin
`Surrounded by an insulating material which in turn is
`encased in a metal body. Two types of construction are
`generally used. In one type, the center pin is insulated and
`bonded in place with the outer metal body by a fused glass
`insert located at Some distance from each end of the metal
`body. A ceramic insulator is then inserted in the ends and
`bonded in place with an epoxy adhesive. The fused glass
`functions both as an insulator and as a hermetic seal. In
`another type of construction, the centerpin is insulated from
`the outer metal body by a one piece ceramic insulator that is
`bonded to the pin and metal body with a metallic brazing
`material. In this case, the ceramic material functions as the
`insulator and the braze functions as the hermetic seal. This
`device generally represents the prior art devices now in use.
`Examples of such connectors are included in U.S. Pat. Nos.
`3,793,608 and 3,898,731, each of which is incorporated
`herein by reference. Commercial connectors of this type are
`available from Kemlon Products, Pearland, Tex. A plastic
`bodied connector of somewhat similar construction is
`described in U.S. Pat. No. 5.203,723, which is incorporated
`herein by reference.
`0006 An outline of a typical connector as described
`above is shown in FIG. 1, where connector 4 has a con
`ductor pin 2 that extends through connector body 1 and is
`internally configured and sealed as described above. Con
`nector 4 is commonly screwed into a closely dimensioned
`port in bulkhead 7 (see FIG. 2) such that elastomer o-ring
`8 in groove 3 is compressed between the groove 3 and an
`inner diameter Surface 11 of the port to prevent the passage
`of high pressure fluid 10 past o-ring seal 8 and contaminate
`the interior atmospheric pressure area 15. As is common in
`high pressure applications, back-up ring 9 may be inserted
`
`in the groove to prevent the extrusion of elastomer o-ring 8
`into the gap between housing 1 and surface 11. The effec
`tiveness of back-up rings at high pressures and temperatures
`is critical to the proper operation of this type of sealing
`configuration. Back up ring 9 is commonly spirally cut, also
`called a Scarf cut. Such that it may be collapsed to the outer
`diameter of groove 3 during installation. Then, high pressure
`fluid 10 acting on o-ring 8 is used to force back-up ring 9 to
`extend out past the edge of groove 3 to contact surface 11
`and prevent extrusion of o-ring 8. At high pressure, it is
`common for o-ring 8 to exert a large axial force on back-up
`ring 9 such that the friction between back-up ring 9 and the
`wall of groove 3 is too great to allow sufficient movement of
`back-up ring 9 to close the gap between the connector and
`surface 11. This leads to extrusion of o-ring 8 and commonly
`failure of the seal. This allows downhole fluid 10 to pen
`etrate the atmospheric area 15 with catastrophic conse
`quences. It is also common for personnel to install the
`back-up rings on the wrong side of the o-ring Such that there
`is no tendency for the back-up ring to be properly actuated.
`0007. There is a demonstrated need for a highly reliable
`connector seal for high pressure high temperature environ
`ments. The present invention addresses these and other
`shortcomings of the prior art described above.
`
`SUMMARY OF THE INVENTION
`0008. The present invention provides an electrical con
`nector for use in downhole environment. In one aspect, the
`invention provides an electrical connector, comprising a
`Substantially cylindrical connector body having a first end
`and a second end. A groove is formed around an outer
`surface of the connector body wherein the groove has a first
`substantially conically beveled surface on a side of the
`groove proximate the second end. A back-up ring has a
`second Substantially conically beveled Surface and is
`adapted to act cooperatively with an elastomer seal to close
`an extrusion gap between the connector body and a Sur
`rounding Surface when the elastomer seal is exposed to a
`positive differential pressure from the first end to the second
`end.
`0009. In another aspect, an electrical connector system
`comprises a Substantially cylindrical connector body having
`a first substantially conical surface formed on a first end of
`the connector body. A second Substantially conical Surface is
`formed in a port of a bulkhead. A locking nut is threadedly
`engagable with the bulkhead such that the locking nut forces
`the first conical Surface in contact with the second conical
`Surface to form a seal when the locking nut is engaged with
`the bulkhead.
`0010. In another aspect, the present invention provides a
`method of sealing an electrical connector in a downhole
`environment by providing a Substantially cylindrical con
`nector body having a first end and a second end. A groove
`is formed around an outer surface of the connector body, the
`groove having a first Substantially conically beveled Surface
`on a side of the groove proximate the second end. A back-up
`ring is provided that has a second Substantially conically
`beveled surface and is adapted to act cooperatively with an
`elastomer seal to close an extrusion gap between the con
`nector body and a Surrounding Surface when the elastomer
`seal is exposed to a positive differential pressure from the
`first end to the second end.
`
`SWM and NexTier Ex. 1034 – Page 6
`SWM and NexTier v. DynaEnergetics
`PGR2021-00097 – U.S. Patent No. 10,844,697
`
`

`

`US 2006/0189208 A1
`
`Aug. 24, 2006
`
`0011. In yet another aspect, the present invention pro
`vides a method of sealing an electrical connector in a
`downhole environment, comprising providing a Substan
`tially cylindrical connector body. A first substantially conical
`surface is formed on a first end of the connector body. A
`second Substantially conical Surface in a port of a bulkhead.
`A locking nut is engaged with the bulkhead, wherein the
`locking nut engagement forces the first conical Surface in
`contact with the second conical Surface to form a seal. These
`and other aspects of the present invention are more clearly
`described in the drawings and specification that follows.
`
`BRIEF DESCRIPTION OF THE DRAWINGS
`0012 For detailed understanding of the present inven
`tion, references should be made to the following detailed
`description of the preferred embodiment, taken in conjunc
`tion with the accompanying drawings, in which like ele
`ments have been given like numerals and wherein:
`O013)
`FIG. 1 is a sketch of a prior art connector;
`0014 FIG. 2 is a sketch of a prior art connector with a
`conventional back-up ring;
`0.015
`FIG. 3 is a sketch of a common wireline logging
`system;
`0016 FIG. 4 is a sketch of a connector having a beveled
`back-up ring according to one embodiment of the present
`invention;
`0017 FIG. 5 is a sketch showing the details of the
`back-up ring of FIG. 4;
`0018 FIG. 6 is a sketch of a connector having a metal
`to-metal seal according to one embodiment of the present
`invention; and
`0019 FIGS. 7 and 8 are exploded views of the connector
`of FIG. 6.
`
`DESCRIPTION
`0020 Referring initially to FIG.3, there is shown a cable
`head 10 supported by a wireline 12 from a rig 14 at the
`surface 16. The releasable cable head 10 supports a tool
`string 18 disposed adjacent a production Zone 22 located, for
`example, near the bottom 24 of a borehole 20, also called a
`wellbore. Wireline 12 is deployed from a reel 29 on wireline
`vehicle 28 around one or more sheave wheels 26 down
`borehole 20. Wireline vehicle 28 has instrumentation, well
`known in the art, for communication and control of cable
`head 10 and tool string 18.
`0021 Wireline 12, sometimes referred to as a cable,
`typically includes a plurality of electrical conductors extend
`ing from wireline vehicle 28 to cable head 10, all well
`known in the art. One such type of multi-conductor wireline
`12 includes an inner core of seven electrical conductors
`covered by an insulating wrap. An inner and outer steel
`armor sheath is then wrapped in a helix in opposite direc
`tions around the conductors. The electrical conductors are
`used for communicating power and telemetry between wire
`line vehicle 28 and tool string 18. Alternatively, the wireline
`cable may contain a combination of electrical conductors
`and optical fibers. A single electrical conductor cable may
`also be used. Tool string 18 may include multiple logging
`tools, perforating guns, packers, and/or any other device
`
`Suitable for running on a wireline and performing downhole
`operations. The downhole tools may be exposed to fluid
`pressures up to 30,000psi and temperatures up to 500F. The
`downhole fluid may be brine, water based drilling fluid, oil
`base drilling fluid and/or fluids that may contain hydrogen
`sulfide, carbon dioxide, methane, and other deleterious
`compounds.
`0022. In order to transfer the electrical power and signals
`between wireline 12 and tool string 18, a connector is used.
`According to one embodiment, connector 40, see FIG. 4, is
`inserted in a suitable port similar to that shown in FIG. 2.
`Connector 40 may be of similar internal construction to any
`of the connectors described as prior art. Connector body 41
`has connector pin 42 extending therethrough and conducts
`energy from the high fluid pressure area 10 to the low fluid
`pressure area 15, where the high pressure is the downhole
`fluid pressure and the low pressure may be atmospheric
`pressure. In addition, the high pressure fluid may be a liquid
`while the low pressure fluid may be a gas. Thus a substantial
`positive differential pressure is exerted across connector 40
`from the high pressure end to the low pressure end. Con
`nector pin 42 is sealed to connector body 41 using tech
`niques known in the art. O-ring groove 43 has a conically
`beveled wall surface 44. Back-up ring 49 is inserted between
`conically beveled wall section 44 and o-ring 48. Back-up
`ring 49 has conically beveled surface 51 where the angle 0'
`is substantially the same as the angle 0 of conically beveled
`surface 44, see FIG. 5. Angles 0 and 0' are in the range of
`about 40° to 50° and preferably about 45°. At an angle of
`45°, the axial displacement of the back-up ring is equal to
`the radial displacement into gap 53. Angle 0 is referenced to
`the bottom of groove 43 where the bottom of groove 43 is
`also substantially parallel to a centerline 80 through the
`connector. As shown in FIG. 5, high pressure acting on
`o-ring 48 forces o-ring 48 against back-up ring 49 Subse
`quently forcing back-up-ring 49 up conically beveled Sur
`face 44 and into gap 43 between shoulder 50 and surface 11
`of bulkhead 7. Back-up ring 49 is scarf cut to allow
`expansion as it moves up conically beveled Surface 44.
`O-ring 48 continues to force back-up ring 49 into gap 53
`until back-up ring 49 contacts surface 11. When back-up
`ring 49 is forced into contact with surface 11, there is
`essentially no extrusion gap for o-ring 48 to move into,
`thereby preventing extrusion damage and failure to o-ring
`48. Back-up ring 49 is made of a material that retains
`Sufficient mechanical strength at the downhole temperature
`while in contact with the different downhole fluids. Back-up
`ring 49 may be made of a thermoplastic Such as polyether
`ketone (PEK), polyetherether ketone (PEEK), or any other
`Suitable thermoplastic material. Alternatively, back-up ring
`49 may be made of a metallic material. O-ring 48 may be
`made of any elastomer material suitable for the downhole
`temperature, pressure, and fluid chemistry conditions. Such
`materials include, but are not limited to, perfluoroelastomers
`and tetrafluroethylene-propylene elastomers known in the
`art. While described above for a single conductor connector,
`multiple conductor connector bodies are within the scope of
`the present invention. While described above in relation to
`an elastomer o-ring, the present invention encompasses
`other shape elastomer seals suitable for insertion in Such a
`groove. This includes, but is not limited to square-shaped,
`oval-shaped, and rectangular-shaped elastomer seals, where
`the shape refers to the cross-sectional shape of the seal.
`
`SWM and NexTier Ex. 1034 – Page 7
`SWM and NexTier v. DynaEnergetics
`PGR2021-00097 – U.S. Patent No. 10,844,697
`
`

`

`US 2006/0189208 A1
`
`Aug. 24, 2006
`
`0023. In another embodiment, see FIGS. 6 and 7, seal
`assembly 75 comprises a conductor 66 sealed to and sur
`rounded by insulator 63 that is disposed in connector body
`72. Connector body 72 has a conically tapered nose surface
`61 that contacts a similarly conically tapered bulkhead
`sealing surface 62 in bulkhead 64. Locking nut 78 is
`threaded into bulkhead 64 by engagement of threads 76 and
`77, and locking nut shoulder 71 contacts connector body
`shoulder 70 forcing nose surface 61 into contact with
`bulkhead sealing surface 62. Angle 0" is in the range of
`about 25° to 35° and preferably about 30°. As shown in FIG.
`8, angles 0" and 0" may be different by about 1-2 to
`ensure a circumferential line contact between surfaces 61
`and 62 enabling a more controlled metal-to-metal seal.
`0024 End 65 of locking nut 78 is shaped to form a hex
`nut shape or other suitable shape to allow sufficient tight
`ening of locking nut 78 in bulkhead 64 to effect a circum
`ferential metal-to-metal seal between the conical surfaces 61
`and 62. Connector body 72 may be made of a metal material,
`or alternatively, a thermoplastic material. Such as, for
`example, those described previously. Locking nut 78 is
`made from a metal material suitable for downhole use.
`0025. While described above in relation to wireline type
`tools, it is intended that the scope of the present invention
`encompasses such a connector in Measurement-While-Drill
`ing tools and completion and production tools, as well. Such
`a connector may also be used in Subsea applications. In
`addition, the sealing mechanisms and methods described
`herein may be used on hydraulic connectors, optical fiber
`connectors, and any Suitable feedthrough that requires a
`reliable seal between a high pressure fluid and a low pressure
`fluid. Note that a low pressure fluid encompasses pressures
`below atmospheric pressure.
`0026. While there has been illustrated and described a
`particular embodiment of the present invention, it will be
`appreciated that numerous changes and modifications will
`occur to those skilled in the art, and it is intended in the
`appended claims to cover all those changes and modifica
`tions.
`
`1. An electrical connector, comprising:
`a connector body having a first end and a second end;
`a groove formed around an outer Surface of the connector
`body, the groove having a first Substantially conically
`beveled surface on a side of the groove proximate the
`second end;
`a back-up ring having a second Substantially conically
`beveled surface and adapted to act cooperatively with
`an elastomer seal to close an extrusion gap between the
`connector body and a Surrounding Surface when the
`elastomer seal is exposed to a positive differential
`pressure from said first end to said second end.
`2. The electrical connector of claim 1, further comprising
`a conductor pin sealably disposed through the connector
`body.
`3. The electrical connector of claim 1, wherein the backup
`ring is made from a thermoplastic material.
`4. The electrical connector of claim 1, wherein the elas
`tomer seal is chosen from the group consisting of (i) an
`o-ring, (ii) a square-shaped ring, (iii) an oval-shaped ring,
`and (iv) a rectangular-shaped ring.
`
`5. The electrical connector of claim 1, wherein the elas
`tomer seal is an o-ring.
`6. The electrical connector of claim 1, wherein the first
`Substantially conical Surface forms an angle with a center
`line of the connector body in the range of about 40°-500°.
`7. An electrical connector system, comprising:
`a connector body;
`a first substantially conical surface formed on a first end
`of the connector body;
`a second Substantially conical Surface formed in a port of
`a bulkhead;
`a locking nut threadedly engagable with the bulkhead, the
`locking nut forcing the first conical Surface in contact
`with the second conical surface to form a seal when the
`locking nut is threadedly engaged with the bulkhead.
`8. The electrical connector of claim 7, further comprising
`a conductor pin Sealably disposed through the connector
`body.
`9. The electrical connector of claim 7, wherein the con
`nector body is made from a material chosen from the group
`consisting of (i) a metal and (ii) a thermoplastic.
`10. The electrical connector of claim 7, wherein the first
`conical Surface and the second conical Surface form an angle
`with a centerline of the connector of about 25°-35°.
`11. The electrical connector of claim 7, wherein a first
`angle of the first conical Surface and a second angle of a
`second conical surface differ by less than 3.
`12. A method of sealing an electrical connector in a
`downhole environment, comprising:
`providing a connector body having a first end and a
`second end;
`forming a groove around an outer Surface of the connector
`body, the groove having a first Substantially conically
`beveled surface on a side of the groove proximate the
`second end;
`providing a back-up ring having a second Substantially
`conically beveled Surface and adapted to act coopera
`tively with an elastomer seal to close an extrusion gap
`between the connector body and a surrounding Surface
`when the elastomer seal is exposed to a positive dif
`ferential pressure from said first end to said second end.
`13. The method of claim 12, further comprising disposing
`a conductor pin through the connector body.
`14. The method of claim 12, wherein the back-up ring is
`made from a thermoplastic material.
`15. The method of claim 12, wherein the elastomer seal is
`chosen from the group consisting of (i) an o-ring, (ii) a
`square-shaped ring, (iii) an oval-shaped ring, and (iv) a
`rectangular-shaped ring.
`16. The method of claim 12, wherein the elastomer seal is
`an O-ring.
`17. The method of claim 12, wherein the first substantially
`conical Surface forms an angle with a centerline of the
`connector body in the range of about 40°-50.
`18. A method of sealing an electrical connector in a
`downhole environment comprising:
`providing a connector body;
`forming a first Substantially conical Surface on a first end
`of the connector body;
`
`SWM and NexTier Ex. 1034 – Page 8
`SWM and NexTier v. DynaEnergetics
`PGR2021-00097 – U.S. Patent No. 10,844,697
`
`

`

`US 2006/0189208 A1
`
`Aug. 24, 2006
`
`forming a second substantially conical Surface in a port of
`a bulkhead;
`engaging a locking nut with the bulkhead, the locking nut
`engagement forcing the first conical Surface in contact
`with the second conical Surface to form a seal.
`19. The method of claim 18, further comprising a con
`ductor pin Sealably disposed through the connector body.
`20. The method of claim 18, wherein the connector body
`is made from a material chosen from the group consisting of
`(i) a metal and (ii) a thermoplastic.
`21. The method of claim 18, wherein the first conical
`Surface and the second conical Surface form an angle with a
`centerline of the connector of about 25°-35°.
`
`22. The method of claim 18, wherein a first angle of the
`first conical Surface and a second angle of a second conical
`surface differ by less than 3.
`23. The electrical connector of claim 1, wherein the
`connector body comprises a Substantially cylindrical sec
`tion.
`24. The electrical connector system of claim 7, wherein
`the connector body comprises a Substantially cylindrical
`section.
`25. The method of claim 12, wherein the connector body
`comprises a Substanually cylindrical section.
`26. The method of claim 18, wherein the connector body
`comprises a Substantially cylindrical section.
`
`k
`
`k
`
`k
`
`k
`
`k
`
`SWM and NexTier Ex. 1034 – Page 9
`SWM and NexTier v. DynaEnergetics
`PGR2021-00097 – U.S. Patent No. 10,844,697
`
`