Patent Application
20050070141
This invention relates to electrical connections, and more particularly to apparatus for the safe electrical connection of electrical components in harsh environments such as in oil well drill strings.
In oilfield and gas drilling operations, electronic equipment such as pressure probes, directional sensing probes, and the like are typically all located together down-hole in a well-bore and co-axially within one drill pipe of a multi-pipe drill string. The probes each have multiple electrical contacts which require electrical mating connection to be made with a mating electrical connection in an up-well segment of another drill pipe/collar. The up-well drill pipe typically contains additional electronic equipment such as a battery power supply as well as transmitting equipment powered by such battery power supply, for powering such sensors in said down-hole pipe and for powering transmitters for transmitting information received from such sensors via the mating electrical connection up-well to surface receptors and data recorders.
More particularly, in an underground drilling environment, measurement or logging instruments are often employed to provide information regarding the drilling status, performance or environment. This information may be stored in memory or telemetered to surface in real time. The measurement and/or telemetry tools are typically battery or generator powered and both the electronics and batteries are contained in pressure resistant housings mounted concentrically along the central axis of the drill collars forming an annulus within the drill pipe through which high-pressure drilling fluid is passed.
The measurement/telemetry tools of the type described above must withstand extremes of pressure, vibration and temperature. Depending on the combination of measurement/telemetry tools chosen, they may exceed the approximate 30′ length of standard drill pipe/collars, or specific sensors may be rigidly fixed to shorter sections of modified drill collars. In this case, electrical tools must span more than one drill collar. Difficulty occurs with the need to simultaneously mate and unmate both the drill collars and the internal electrical housings, yet do so in a manner in which the electrical connections are shielded from the environment to not only protect the electrical connections from a corrosive, potentially explosive, and/or wet environment which would be detrimental to establishing electrical connection, but also from physical damage or deformation to the electrical connectors during the mating and un-mating connection of drill strings and the associate required mating and un-mating connection of electrical connectors axially situate within respective adjacent drill pipe/collars.
In addition, a further problem arises where mating connection between co-axial male plug and mating female socket connections are required to establish such electrical connection. In particular, where electrical connection is required between a coaxial male plug, having multiple circumferential spaced apart electrical contacts thereon, and a female socket connector having a mating diameter and a corresponding number of electrical contacts thereon. Specifically, the procedure of engaging a male plug having a plurality of circumferential electrical connections thereon within a coaxial female socket aperture so as to form the electrical connection with the multiple electrical contacts thereon will cause many of the contacts in the male plug to “wipe” past those of the female socket during insertion, generally in an electrically inappropriate manner, that may damage the electronic circuits associated with such contacts before the contacts are each fully and appropriately engaged with the responding electrical contact. In addition, a further problem arises in that the preferred method of making such electrical connections is typically to insert by rotationally screwing one tubular housing containing the male plug into a similar tubular housing containing the female socket. The environment in which this occurs could also be hazardous—for instance, on the floor of an oil-drilling rig where flammable gases may be present. In such circumstances it is advisable to make certain that no potentially live electrical contacts are capable of causing a spark or thermal effect that could ignite flammable gas, dust or vapor during rotatable insertion of the male plug into the female socket.
Accordingly, a means and apparatus to allow for the joining of the internal electrical connections is desired, and in particular in a down-hole drilling application to allow electrical connection between electronic componentry located in two or more separable drill pipes to be accomplished.
Referencing U.S. Pat. No. 6,123,561,U.S. Pat. No. 6,392,317, and U.S. Pat. No. 5,334,801, prior methods for drill collar electrical connections have included electrical connectors integral to the drill collars. This arrangement requires specialized drill collars, and makes required recutting of the mating threads an additional step and expense, and also requires a method to transfer the electrical leads back and forth between drill collars and internal electrical components.
Additional patents such as U.S. Pat. No. 5,389,003, U.S. Pat. No. 6,439,932, and U.S. Pat. No. 5,358,418 teach a class of connectors referred to as “wet connects”. These connectors, while primarily employed to make electrical connections downhole between a wireline cable and probe, have also been employed in an attempt to make interconnections between probes mounted in drill collars. The art is not well suited for this application, as the wet connects tend to be elongated to the point that they extend out of the drill collar connections, making them subject to damage. Further, the unconnected contacts are generally exposed, and this makes safety a concern in hazardous environments, where the exposed contacts could create a spark.
In order to overcome certain of the disadvantages of the prior art, the present invention in a broad aspect thereof provides two connector halves matingly engageable in co-axial arrangement, where the electrical contacts on each of the connector halves are physically covered in order to protect electrical contacts on each of said connector halves from environmental damage. The first connector half (which includes a male member on the plug means) is protected by a resiliently-biased outer insulating sleeve or sheath. The sheath contains one or more seals and acts to shield electrical contacts on the male member from dirt, corrosion, or the like.
The second connector half (the socket means) has a female receptacle, the inner periphery of which possesses a plurality of electrical contacts (corresponding to the number of electrical contacts on the male member). The electrical contacts within the female receptacle are protected by a resiliently-biased movable member, which in a preferred embodiment is a sliding piston member. The piston member and/or female receptacle includes one or more seals to shield electrical contacts within the female receptacle from the environment.
In a preferred embodiment, such as where the connector halves are installed respectively in mating drill pipes, the two connector halves are each contained in pressure-resistant housings which support and centrally locate the connector halves within the respective drill pipe, and are capable of withstanding external pressure.
During the connection of the two connector halves, namely the plug and socket means, the male member on the plug means displaces the resiliently-biased piston member while the socket member displaces the resiliently-biased sheath member. The connector halves each continue to displace the protective shields on the mutually opposite connector half until mating engagement is complete, at which time the male member should be fully inserted in the female receptacle means, and each of the electrical contacts on each of the male member and the female receptacle means are properly aligned. This fully-engaged position may also be determined when the respective pressure-resistant housings containing each connector half shoulder against one other at which time the connectors have reached proper alignment of all respective co-axial conductors.
In the preferred embodiment where each of such connector halves are fixedly installed respectively within the interior of mating drill pipes which are then threadably coupled together, a third resiliently biasing means, such as a spring, may further be provided. Such further resilient biasing member functions, during threading of the drill members together and thereafter, to exert a force to ensure that the connectors remain fully mated while allowing for some variation in the length of the threaded members.
In a further aspect to the present invention, when such plug and socket means are each contained in respective mating pressure housings [which assist in preventing exterior liquids and gases from coming into contact with electrical contacts of such plug and socket means as is necessary when such plug and socket means are installed respectively in mating drill pipes], at least one of the pressure housings may be configured in such a way so as to utilize the ambient pressures surrounding such housings and within such drill pipe to exert a force which assists in maintaining the pressure housings containing such plug and socket means in mating engagement.
In a preferred embodiment, electrical switching circuits are connected to the electrical contacts situate on one or both of said male member and female receptacle means. Such electrical switching circuits serve to prevent the flow of electrical power to respective electrical contacts in either or both the male member or female receptacle means until the connecting halves are fully mated. Through the electrical switches, the multiple electrical contacts of the male and female connectors are electrically isolated (ie “switched off”) as they slide past one another, and are only electrically powered after mating engagement of the plug means with the socket means is complete.
During unmating, the electrical switches cut power prior to the conductors sliding past each other. The resiliently-biased sheath and piston member move back over the electrical contacts so as to again cover and thus protect the electrical contacts from the environment. Reference is to be had to pending U.S. patent application Ser. No. ______ filed Sep. 4, 2003 assigned to the same entity as this within application, the entity of the subject matter of which is incorporated herein by reference.
Accordingly, in one of its broad embodiments the present invention is to a plug and socket means adapted for mating engagement, for establishing electrical communication there between in a hazardous environment. The plug means comprises:
In a preferred embodiment the resiliently-biased protective means comprises a piston member, slidably-biased within said receptacle means, adapted to substantially cover said electrical contacts disposed on said inner periphery of said female receptacle means when said male member is not yet inserted in said female receptacle means. The piston member is displaceable from within said receptacle means by the male member upon insertion of said the member in said receptacle means.
In yet a further refinement, the socket means further comprises means for contacting the sheath member upon mating engagement of said plug means with said socket means, so as to cause said sheath member to be slidably displaced from a position covering said male member as said male member is inserted in said receptacle means.
In a preferred embodiment, the plug means and socket means is contemplated for use in two separate drill pipes which are desired to be matingly engaged to one another during drilling, typically by threadable engagement, and more particularly is contemplated as providing apparatus for establishing electrical connection between a plug means and associated electrical componentry in one drill pipe, and a socket means and its associated electrical componentry located within another drill pipe which will be connected to one another during drilling. In such embodiment the plug means is adapted for positioning within an interior of a first drill pipe proximate an end thereof, said end of said drill pipe adapted for mating engagement with a mating end of another drill pipe, and said socket means is adapted for positioning within an interior of said another drill pipe proximate said mating end thereof; wherein said male member is adapted for insertion in said receptacle means upon said first drill pipe being fitted in mating engagement with said another drill pipe.
More particularly, in an embodiment of the invention contemplated for use in drill pipe, for establishing electrical connection between electrical componentry in each of two respective drill pipes, the present invention comprises plug and socket means adapted for respective positioning within two separate drill pipes and adapted to permit electrical communication between components situated in each of said two separate drill pipes and further adapted for mating engagement upon rotatable engagement of said two separate drill pipes with each other; said plug means comprising:
In yet a further preferred embodiment, particularly suited where the plug means and the socket means are contemplated each for location in two separate drill pipe which are to be rotatably engaged with each other during drilling, the plug means is rotatable relative to said socket means to permit said socket means to rotate relative to said plug means during rotatable mating engagement of said two separate drill pipes with each other.
In a further refinement of the embodiment of the invention contemplated for use in association with two separate drill pipes, said plug means is adapted for positioning within an interior of a first of said two separate drill pipes proximate an end thereof adapted for mating engagement with a mating end of a second of said two separate drill pipes, and said socket means is adapted for positioning within an interior of said second of said two separate drill pipes proximate said mating end thereof; and said male member is inserted in said receptacle means upon said first drill pipe being fitted in mating engagement with said second drill pipe.
In a further embodiment, due to a problem that when the male member is inserted within the female member there may temporarily be inappropriate electrical contact made due to electrical contacts on the male member “wiping” past the electrical contacts on the elongate receptacle means until full engagement of the male member within the female receptacle means, in a preferred embodiment means is further provided to avoid such inadvertent and inappropriate connections being temporarily made which would otherwise possibly result in damage to associated electrical circuitry.
Accordingly, in a further preferred embodiment, said plurality of electrical contacts disposed a bout said periphery of said male member comprise first and second plug contacts, electrically coupled to each other via plug-side current direction-limiting means; said plurality of electrical contacts disposed about said inner periphery of said receptacle means comprising first and second socket contacts, situate in said receptacle means and adapted to correspondingly come into electrical contact respectively with said plug contacts when said plug means is properly and fully matingly engaged with said socket means, said first and second socket contacts electrically coupled to each other via socket-side current direction-limiting means; at least one additional plug contact and socket contact on each of said plug and socket means, respectively, each similarly adapted to come into electrical contact with each other when said plug means is fully matingly engaged with said socket means; wherein said plug and socket means are each adapted to be used with circuit isolation means capable of only permitting flow of electrical current through said at least one additional plug and socket contact when current flow through at least one of said plug side and socket side current direction-limiting means is detected. Reference is to be had to U.S. patent application Ser. No. ______ filed Sep. 4, 2003 assigned to the same entity as the written application, the entire contents of which are incorporated herein by reference.
In yet a further embodiment, third biasing means (in addition to the biasing means possessed by each of the plug means and socket means) is further provided. Such third biasing means is adapted, when said plug means and said socket means are in mated engagement, to exert a force so as to maintain said plug means in mating engagement with said socket means. This feature is particularly advantageous where the plug and socket connectors are subjected to vibrations and jarring, typical of the types of environmental stresses subjected to drill strings during drilling.
In a preferred embodiment, were the plug and socket are intended to be used in respective mating drill pipes, the socket means is contained in a first pressure housing, said first pressure housing attachable to an interior of said first drill pipe. The plug means is contained in a second pressure housing, said second pressure housing positionable within an interior of said second drill pipe; a portion of the second pressure housing being slidably moveable within a third pressure housing, said third pressure housing attachable to an interior of said second drill pipe; and the second pressure housing is matingly engageable with said first pressure housing along a common longitudinal axis.
In a further refinement of the invention where the plug and socket means are contained in pressure housings, the second pressure housing is provided with an area of reduced cross-sectional area so as to present a surface area normal to said longitudinal axis of said first and second pressure housing so that ambient pressure within said first and second drill pipes acts on said surface area so as to cause said second housing to be biased in mating engagement with said first housing.
Likewise, instead of locating the socket means within the first pressure housing member and the plug means within the second pressure member, the order may be reversed. Accordingly, in such embodiment, the plug means is contained in the first pressure housing, said first pressure housing attachable to an interior of said first drill pipe; the socket means is contained in the second pressure housing, said second pressure housing positionable within an interior of said second drill pipe; a portion of the second pressure housing is slidably moveable within a third pressure housing, said third pressure housing attachable to an interior of said second drill pipe; and the second pressure housing is matingly engageable with said first pressure housing along a common longitudinal axis.
Likewise, in a further refinement of the above embodiment where the plug and socket are intended to be used in respective mating drill pipes, the second pressure housing is provided with an area of reduced cross-sectional area so as to present a surface area normal to said longitudinal axis of said first and second pressure housing so that ambient pressure within said first and second drill pipes acts on said surface area so as to cause said second housing to be biased in mating engagement with said first housing.
Lastly, in yet another aspect of the present invention, such invention provides for a method for establishing electrical communication between a plug means in a first drill pipe and a socket means in a second drill pipe, comprising the steps of:
Further advantages and permutations will appear from the following detailed description of various non-limiting embodiments of the invention, taken together with the accompanying drawings, in which:
The description will be made in reference to the invention being used to connect electrical equipment mounted concentrically within drill collars or drill pipes, for drilling boreholes in the earth, although the invention has application in electrically connecting any mating members.
Referencing
In a preferred embodiment, socket means 14 and associated receptacle 20 and pressure housings 15 are positionable in a first drill pipe 26, and plug means 12 and associated male member 16 are positionable within a second drill pipe 28, as shown in
In typical drilling rig operating conditions, the female end 27 drill pipe 26 faces upward, and the male end 29 of drill pipe 28 is lowered down to it by using a winch or similar system, and thereafter rotated so as to permit mating engagement of drill pipes 26,28 together. However, in lowering pipe 28 onto pipe 26, it is typical that the male end 29 of the drill pipe 28 will on occasion swing across the female end 27 of drill pipe 26, and would severely damage plug means 12 if it were to protrude from male end 29 of drill pipe 28. Similarly, socket means 14 could be similarly damaged if it were to protrude from female end 27 of drill pipe 26 by male end 29 of drill pipe 28. Accordingly, in a preferred embodiment, each of plug means 12 and socket means 14 are recessed from the respective male and female ends 29, 27 of drill pipes 28, 26 respectively, in order that plug means 12 and male member 16 thereon as well as socket means 14 and receptacle 20 thereon are protected from inadvertent contact with and potential damage during handling of the drill pipes 26, 28.
In a preferred embodiment, an electronic switch 40 (identified in FIGS. 6 as item 202 for the purposes as explained later herein) is contained within the pressure housing 33b. A further pressure housing 41 is provided, slidably mounted on a portion of pressure housing 33b, as shown in
While pressure housing 15 and associated socket means 14 may rotate relative to plug means 12 and associated housing 33a,b, relative rotation between the pressure housings 33a,b and 41 is prevented with a splined, anti-rotation sleeve 42, which is fixed at a first location 42a to pressure housing 41, and splined at a second location 42b to pressure housing 33b. The heavy compression spring 43 allows the slidable assembly to compensate for axial mis-alignment of the two pressure housings 33a,b and 15. Axial mis-alignment may be of some reasonable amount, within a quarter of an inch, for instance, which results when the socket means 14 and associated drill pipe 26 is mated to plug means 12 and associated drill pipe 28. (see
The male member 16 mounts to plug means 12 via mounting rod 43, which is held in place by a washer 44 and a snap ring 45 (See
Outer pressure housing 15 houses an inner housing 61, which encloses compression spring 56, non-conductive piston 55, and an electronics carrier 62. Electronics carrier 62 may contain such things as a battery power supply and/or radio frequency transmitter, and/or one or more sensors, all of which are typically located in downhole members such as aforesaid drill pipe 26, and which require electrical connection via plug means 12 and wires 52a, b to up-well electronic equipment.
Receptacle 20 mounts onto the end of an inner housing 61. An elastomeric shock absorber/seal 64 is mounted between at the interface between the inner surface of pressure housing 15 and the outer periphery of the receptacle 20 to prevent contaminents and foreign matter from entering pressure housing 15 and inner housing 61. A threaded mount 65 supports electronics carrier 62 and retains the compression spring 56. A coupling 66 in turn supports threaded mount 65, and permits passage of wires 90 from electronics carrier 62 down-pipe within pipe 26. An off-the-shelf electrical connector 67, such as an ITT-Canon MDM connector, mounts on the coupling 66 to provide electrical connection to the down-pipe mating components, which may consist of additional sensors, telemetry modules, power supplies, or other electrical equipment (not shown).
As may be seen from
Advantageously, as the joining of the drill pipe 26, 28 continues past the full mating of the plug means 12 and socket means 14, namely past the full mating engagement of male member 16 within receptacle 20, additional axial travel compresses the stiffer compression spring 43. Spring 43 provides continual clamping force on the plug 12 and socket 14 means while allowing for variation in the threaded length of the joining members, namely drill pipes 26 and 28.
With reference to
For the purpose of demonstrating the above principle, a simplified diagram is used as shown in
While there are many methods of connecting two electronic circuits together, in one aspect the invention contemplates use of a coaxial plug and socket pair 212 and 226 respectively, as indicated in
It will be noted that the sensor lines 292, 294 on the socket sensor circuit 257 are crossed with respect to the sensor lines 280, 282 on the plug circuit 256; apart from this circuits and wiring for both plug and socket sensor circuits 256, 257 are identical. The plug-side and socket side sensor circuits 256, 257 may alternatively be arranged as shown in
To clarify how the units sense that the plug/socket combination has achieved full engagement, we proceed by explaining various embodiments.
Embodiment 1
As may be seen with reference to
It will be obvious to one reasonably skilled in the art that there should be no electrical circuits associated with socket 226 such as digital switches 245 that are in electrical communication with any of the non-sensor contacts 213 that would be electrically mistaken for the action of diode 302, so as to otherwise initiate a “triggering” of the power switch 244. To further guard against such a possibility, in a preferred embodiment of this aspect of the invention the output of sensor circuit 256 in respect of the plug sensor circuitry is passed through timer 259 (
The only significant requirements on the passive socket side is a diode 302 that is forward biased by crossed sensor lines 292, 294 in order that the sensed circuit 256 is correctly activated.
Embodiment 2
The complementary circuit of Embodiment 1 is depicted in
As may be seen with reference to
It will be obvious to one reasonably skilled in the art that there should be no electrical circuits associated with plug 216 such a Digital Switches 246 that are in electrical communication with any of the non-sensor contacts 213 that would be electrically mistaken for the action of diode 276, so as to otherwise initiate a “triggering” of the Power Switch 243. To further guard against such a possibility, in a preferred embodiment of this aspect of the invention the output of Sensor Circuit 257 in respect of the socket sensor circuitry is passed through Timer Circuit 259 (ref.
The only significant requirements on the passive plug side is a diode 276 that is forwarded biased by crossed sensor lines 292, 294 in order that the Sensor Circuit 257 is correctly activated.
Embodiment 3
The discussion of Embodiment 1 and Embodiment 2 above now makes the understanding of Embodiment 3 as exemplified by
The choice of routes a) or b) is determined solely by whether +V(plug) 235 is greater than +V(socket) 236 by more than one diode drop (typically 0.6V). In either case the significant issue is that the plug Sensor Circuit 256 is activated by an adequate +V(socket) 235 potential or by the presence of diode 300—both are associated with the full engagement of the plug and socket, and either will suffice.
Likewise, the potential at sensor circuit 257 (socket) is available in either of two means:
The choice of routes c) or d) is determined solely by whether +V(socket) 236 is greater than +V(plug) 235 by more than one diode drop (typically 0.6V). In either case the significant issue is that the plug Sensor Circuit 256 is activated by an adequate +V(plug) 235 potential or by the presence of diode 276—both are associated with the full engagement of the plug and socket, and either will suffice. Diodes 274 and 300 ensure that there can be no unintended reverse flow into their associated power supplies.
This embodiment illustrates usefulness of the symmetry of the circuit operations attached to either plug or socket—fabrication of the switching circuits is simplified in that both assemblies can be identical. The only necessary modification is that the lines must be crossed between contacts 288, 290 and sensor lines 292 and 294.
With reference to the embodiment shown in
From
Importantly, with respect to each of the embodiments shown in
Although the disclosure described and illustrates preferred embodiments of the invention, it is to be understood that the invention is not limited to these particular embodiments. Many variations and modifications will now occur to those skilled in the art. For definition of the invention, reference is to be made to the appended claims.
