Abstract:
A device for connecting at least one electrical data and/or supply line to electrical sockets of a wired drill pipe is disclosed. One inventive aspect of the device comprises: a collet blocking plug axially insertable into and removable from a receiver end of the drill pipe and at least one collet. The collet is configured to be interlocked with the drill pipe in a locking position and be released from the drill pipe in a release position. The collet is axially displaceable from the collet blocking plug between the locking position and the release position. The collet blocking plug is axially insertable into and removable from a receiver end of the drill pipe.

Description:
CROSS REFERENCE TO RELATED APPLICATIONS 
     This application claims benefit under 35 U.S.C. §119 to European Patent Application No. 12194531.5 entitled “Electrical Tripping Sub for Wired Drill Pipes” filed on Nov. 28, 2012, the disclosure of which is hereby incorporated by reference in its entirety. 
     FIELD 
     The disclosed technology relates generally to wired drill pipes. More specifically, the disclosure is directed to systems, methods, and devices for connecting at least one electrical data and/or supply line to electrical sockets of a wired drill pipe when the drill pipe is not in an active drilling operation. 
     BACKGROUND 
     Currently, simple steel pipes are screwed together in many drilling facilities. In this manner, a drill string is formed to be several kilometers long and a drill bit is attached at an end of the drill string. In an interior of the pipes, there is a rinsing fluid (e.g., mud) for fulfilling a variety of functions during a drilling process. One of those functions may be an transmission of data via pressure pulses. However, since this data transmission is slow (e.g., a typical transmission rate is around 10 Baud), increasing efforts have been undertaken in drilling industries for obtaining bore information during a drilling operation at higher data transmission rates. For example, a downhole data transmission system of U.S. Pat. No. 6,670,880 is shown to transmit data through a plurality of drilling components of a drill string. Each of the drilling components is connected at its two ends to ends of subsequent drilling components. A coaxial cable within each drilling component extends from one end to the other end of the drilling component and is connected to the coaxial cables of adjacent drilling components. During a drilling operation, a swivel enables communications between the downhole data transmission system and instruments positioned at surface. Other transmission mechanisms are also used. For example, sonar or electric currents across the soil, etc. However, solutions based on a wiring of the drill string (e.g., electrical cables or light guides) have turned out to be most efficient. 
     Logging of data from the bore during a drilling process has become an essential element in modern crude oil, natural gas or geothermal drillings. This type of data acquisition is also referred to as Measurement While Drilling (MWD) or Logging While Drilling (LWD). Data acquisition is also important for a construction of the bore and a subsequent production of crude oil, gas and/or warm water. A drilling can be operated safely, efficiently and economically only by accurately determining respective relevant measurements. More data from below ground are available, more efficiently and safely can a drilling operation be organized. Therefore, the drilling industry increasingly demands a transmission of data at high data rates (e.g., 200 kBaud) from a depth of several kilometers. This request results in increasing demands on the power of underground measuring units and therefore, an increase in the electric power consumption of the underground measuring units. In order to account for this increasing electric power consumption, the underground measuring units should be supplied with electric energy (e.g., with 200 W) also from the surface. 
     In PCT Publication No. WO 2010/141969 A2, a device for connecting electrical cables on essential tubular connection elements, which can be screwed to each other, is disclosed, in which a first electrical contact element is firmly arranged on a first connection element and a second electrical contact element is arranged on a second connection element so as to be displaceable in the direction of rotation of the connection element. By means of this device, a problem of the electrical connection between the pipes of the drill string may be solved. The electrical connection has turned out to be reliable, simple and robust for the mechanical connection of pipes (e.g., a rotary movement) and enables a transmission of electric power and/or data under the severe conditions prevailing in the bore, such as a high pollution, the presence of all kinds of liquids, high temperatures and mechanical shocks. Using a drill string constructed in this manner, it is possible to feed electric power into underground measuring units during a drilling process, for example, with the aid of slip ring assemblies arranged at the top-drive and acting as swivels and to read out and evaluate data generated by those underground measuring units. 
     However, in particular for increasing the safety of the bore, it is also necessary to provide energy supply for underground measuring units and to read out data when no drilling operation is performed and the drill string is dismantled (trip-out) or installed by pipes being assembled (trip-in). In addition, it is of utmost importance to know whether changes relevant to safety occur in the bore, such as, e.g., pressure changes, friction, formation of gas bubbles etc. 
     In European Patent No. EP 2,273,058 A2, instruments for providing communications with a wired drill pipe during a tripping operation are disclosed. The instruments can be connected to the drill string and comprise so-called sub-coupler heads. A first type of sub-coupler head has a threadless surface which, during the installation in a wired drill pipe, exerts a retaining force against a thread section of the drill pipe via a friction or press fit. The friction or press fit is achieved by spreading the sub-coupler head. A communication element is embedded in the sub-coupler head to couple communicatively to a pipe communication element, if the sub-coupler head is positioned within the receiver end of the wired drill pipe. Inductive couplers and direct connection couplers, among other things, are mentioned as communication elements. A wiring connection, mud-pulse telemetry, electronic telemetry and/or acoustic telemetry are cited as examples of communicative coupling. The material of the sub-coupler head is elastic or deformable, respectively, and soft with regard to the material of the drill pipe so that the thread of the drill pipe is not damaged. In an alternative exemplary embodiment of the sub-coupler head, its surface exhibits a partial thread. The communication device serves only for the transmission of signals, but not for supplying underground measuring units with electric energy. 
     In U.S. Pat. No. 7,198,118, a communication adapter for a detachable connection to a drilling component outside of the active drilling operation is disclosed. The communication adapter comprises a data transmission coupler for data communication with a transmission system integrated in the drilling component, a mechanical coupler for removably attaching the adapter to the drilling component and an integral data interface comprising a screen, a gauge, a loudspeaker or a light. The mechanical coupler comprises a thread or solenoids or locking mechanisms such as, e.g., elastic clips or clamps. In one exemplary embodiment, the mechanical coupler comprises cams which can be swiveled about a swivel axis into an engagement with an internal thread of the drilling component. The communication adapter serves only for the transmission of signals, but not for supplying underground measuring units with electric energy. 
     The intention of feeding energy, data and/or control signals into and, respectively, out of the drill string during the trip-in and, respectively, trip-out operation of the bore encounters primarily the following difficulties:
         The drill string is not regularly screwed to the slip ring assembly, which, therefore, cannot be used for electrical power supply and communications.   For safety reasons, electric energy supply units, data processing devices and controls are located outside of the drilling rig in a switch cabinet and they must be connected to the drill string via energy supply, status and control lines.   The energy supply, status and control lines must be linked to the drill string via an electromechanical unit which functions highly reliably under the severe operating conditions and in accordance with safety regulations such as those for explosion protection zone 1 and yet is easy to handle for the operating staff, whereby semiautomatic or manual connecting and separating should be possible.       

     The disclosed technology is based on the object of providing a solution to the above-discussed problems associated with feeding electric energy, data and/or control signals into and, respectively, out of the drill string during the trip-in and, respectively, trip-out operation of the bore. 
     SUMMARY 
     Various implementations of systems, methods and devices within the scope of the appended claims each have several aspects, no single one of which is solely responsible for the desirable attributes described herein. Without limiting the scope of the appended claims, some prominent features are described herein. 
     The disclosed technology provides a device for connecting at least one electrical data and/or supply line to drill pipe electrical sockets of a wired drill pipe, when the wired drill pipe is not in an active drilling operation. 
     The disclosed technology also provides a method of connecting at least one electrical data and/or supply line to drill pipe electrical sockets of a wired drill pipe, when the wired drill pipe is not in an active drilling operation. 
     These and other objects of the disclosed technology will be described in or be apparent from the following description of the preferred embodiments. 
     According to an aspect of the disclosed technology, there is provided a device comprising electrical sockets galvanically connecting to the at least one electrical data and/or supply line and contacting with the drill pipe electrical sockets. The device further comprises a collet blocking plug configured to be axially insertable into and removable from a receiver end of the drill pipe and at least one collet configured to be axially displaceable from the collet blocking plug between a locking position and a release position. The collet is configured to be interlocked with the drill pipe in the locking position. The collet is released from the drill pipe in the release position. 
     According to an aspect of the disclosed technology, there is provided a method comprising connecting electrical sockets galvanically to the at least one electrical data and/or supply line and contacting with the drill pipe electrical sockets. The method further comprises interlocking at least one collet with the drill pipe in a locking position and releasing the collect from the drill pipe in a release position. The collet is configured to be axially displaceable from a collet blocking plug between the locking position and the release position. The collet blocking plug is configured to be axially insertable into and removable from a receiver end of the drill pipe. 
     Said object is achieved by a device for connecting at least one electrical data and/or supply line to electrical sockets of a wired drill pipe having the features of claim  1 . Advantageous embodiments are set forth in the subclaims, in the specification and in the drawings. 
     By means of the tripping sub, according to an embodiment, at least one electrical data and/or supply line can be connected to electrical sockets of a wired drill pipe, if the drill pipe is not in the active drilling operation. The tripping sub according to an embodiment comprises: electrical sockets which are galvanically connected to the at least one electrical data and/or supply line and can be brought into contact with the electrical sockets of the drill pipe; a collet blocking plug axially insertable into and removable from a receiver end of the drill pipe; and at least one collet. The collet blocking plug and the collet are axially displaceable relatively to each other between a collet position and a release position, wherein, in the collet position, the collet is configured to interlock with the drill pipe and wherein, in the release position, the engagement of the collet with the drill pipe is undone. 
     The tripping sub according to an embodiment is particularly suitable for being connected to the connection elements of wired drill pipes as described in the above mentioned patent application WO 2010/141969 A2, whereas an adjustment to standard threads of standard drill pipes is not an object of the embodiments. 
     A locking between the tripping sub according to an embodiment and the drill pipe which is fabricable quickly and safely can be achieved if the collet is radially movable, preferably radially movable in an elastic way. 
     If, in the tripping sub according to an embodiment, the collet is radially retractable in the release position, the tripping sub can be guided out of the drill pipe with particular ease. In a preferred construction of an embodiment, the collet blocking plug has at least one indentation, preferably at least one peripheral groove, into which the collet is radially retractable in the release position. Particularly safe handling of the tripping sub according to an embodiment can be achieved if the collet blocking plug has two indentations, preferably peripheral grooves, which are axially offset and define two different release positions. A first release position is thereby taken by a relative axial displacement of the collet blocking plug toward the collet in a first direction, and a second release position is taken by a relative axial displacement of the collet blocking plug toward the collet in the opposite direction. A high mechanical stability of the connection between the tripping sub and the wired drill pipe and protection against loosening of the connection in the occurrence of tensile forces is achieved if, in the collet position, a section of the collet blocking plug forms an abutment against radial retraction of the collet. 
     Good manageability of the tripping sub according to an embodiment is achieved if the collet has projections which are configured to join in indentations of the drill pipe in the collet position or if the collet has indentations which are configured to join in projections of the drill pipe in the collet position. 
     In a space-saving and mechanically highly reliable embodiment of the tripping sub according to an embodiment, the collet is designed as a clamping sleeve surrounding the collet blocking plug. 
     In order to prevent an unintended loosening of the connection to the drill pipe, the tripping sub can be prestressed into the collet position, preferably by means of centering springs. 
     For a particularly high reliability and a fast establishing of the electrical connection, in a preferred embodiment of the tripping sub according to an embodiment, a rotary external body is provided in which the electrical sockets are configured such that they can be brought into contact with the electrical sockets of the drill pipe by a rotary movement of the external body. Providing rotation handles facilitates the turning of the tripping sub for the operating staff. Providing axial running handles generally simplifies the manual guidance of the tripping sub. In a preferred embodiment, the external body and the collet are axially connected with regard to each other in an essentially rigid, but rotatable way. The connection can thereby be implemented by means of a rotation blocking plug which is axially connected to the collet in a rigid way and, on its outer surface, has an external thread onto which an internal thread of the external body is screwed in a rotatable way. The collet and/or the rotation blocking plug can be locked against twisting with regard to the collet blocking plug by a rotation blocking element. Alternatively, the rotation blocking plug can comprise rotation blocking elements for join in the drill pipe. 
     For an automatic or at least semiautomatic connection of the tripping sub to a drill pipe, it is envisaged that the external body is rotatable by means of a motor and optionally a gear, wherein the tripping sub preferably being equipped with actuators for an automatic supply to and take away from the drill pipe. 
     Furthermore, for safety reasons, an electrical detection switch is recommended which detects whether the electrical sockets of the tripping sub are in contact with the electrical sockets of the drill pipe. 
     In order to avoid that the electrical cables twist too much and, as a result, break or their insulation is damaged, it is also envisaged in an embodiment that at least one electrical cable is guided out of the tripping sub in a loom of cables by means of a rotation compensator device. 
     For conducting measurements, for example, on stored drill pipes, it is purposeful to design the tripping sub according to an embodiment as a handheld device, wherein at least one device for feeding and discharging data, status and/or test signals and for evaluating discharged signals is connected to the at least one electrical data and/or supply line, the device preferably having a user interface. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  shows a detail of a drilling facility comprising a tripping sub, in accordance with an exemplary embodiment. 
         FIG. 2  shows the connection of the tripping sub  2  to a swivel body and a wired drill pipe, in accordance with an exemplary embodiment. 
         FIGS. 3 and 4A  show an embodiment of the tripping sub in a perspective illustration, in each case partially sectioned.  FIGS. 4B and 4C  show detailed views E and D, respectively, of  FIG. 4A . 
         FIG. 5  shows an arrangement of a collet and a rotation blocking plug in the tripping sub. 
         FIGS. 6A, 6B, 7-10, 11A, and 11B  show the process of connecting the tripping sub to the drill pipe, in accordance with an exemplary embodiment.  FIG. 6B  shows a detailed view of  FIG. 6A .  FIG. 11B  shows a detailed view of  FIG. 11A . 
         FIGS. 12 and 13  show a process of loosening the connection of the tripping sub to the drill pipe, in accordance with an exemplary embodiment. 
         FIG. 14  shows an exemplary embodiment of the tripping sub having a motor drive. 
         FIG. 15  shows a furnishing of the tripping sub with devices for automatic placement. 
     
    
    
     The various features illustrated in the drawings may not be drawn to scale. Accordingly, the dimensions of the various features may be arbitrarily expanded or reduced for clarity. In addition, some of the drawings may not depict all of the components of a given system, method or device. Finally, like reference numerals may be used to denote like features throughout the specification and figures. 
     DETAILED DESCRIPTION 
     Advantages and features of the disclosed technology and methods of accomplishing the same may be understood more readily by reference to the following detailed description of preferred embodiments and the accompanying drawings. The disclosed technology may, however, be embodied in many different forms and should not be construed as being limited to the embodiments set forth herein. Rather, these embodiments are disclosed so that this disclosure will be thorough and complete and will fully convey the concept of the invention to those skilled in the art, and the disclosed technology will only be defined by the appended claims. Like reference numerals refer to like elements throughout the specification. 
     The drawings and description are to be regarded as illustrative in nature and not restrictive. Like reference numerals designate like elements throughout the specification. 
     Further, since sizes and thicknesses of constituent members shown in the accompanying drawings are arbitrarily given for better understanding and ease of description, the disclosed technology is not limited to the illustrated sizes and thicknesses. 
       FIG. 1  shows a detail of a drilling facility for crude oil, natural gas or geothermal drillings, wherein measuring units arranged at the wired drill string are supplied, via the wiring, with electric energy, control signals and/or data that are sent by the measuring units, via the wired drill string, to control and evaluation devices located above ground. The data transmission also takes place when no drilling operation is performed. But, as is illustrated here, the drill string is demounted (trip-out) or installed by pipes assembled (e.g., trip-in). In  FIG. 1 , a grabber assembly  1  is shown to hold a topmost wired drill pipe  6  of a wired drill string. The upper end, the so-called “box-end,” of the wired drill pipe  6  is referred as a device  2  for connecting electrical data and/or supply lines arranged in a flexible part of a data cable housing sleeve  18 . The data cable housing is connected to electrical sockets of the wired drill pipe  6 . The wired drill pipe  6  is preferably a drill pipe comprising a connection element as described in PCT Patent Publication No. WO 2010/141969 A2. The flexible part of the data cable housing sleeve  18  leads to a data cable housing sleeve  5 . The data cable housing sleeve  5  is fixed to a swivel body  3 . The electrical cables continue from the data cable housing sleeve  5  to a wired mounting sub  4  and proceed to control and evaluate energy supply devices located remotely from the drilling facility. Because of this arrangement, it is possible to control electric circuits located in the drill string and to supply them with energy. During a drilling operation of the drilling facility, the tripping sub  2  is parked in a box  11  so that it neither disturbs the drilling operation, nor can it get damaged. As such, the tripping sub  2  will immediately be available again in subsequent tripping operations. During the drilling operation, the wired mounting sub  4  is directly connected to the wired drill pipe  6 . 
       FIG. 2  shows a connection of the tripping sub  2  to a swivel body  3  and the wired drill pipe  6  in an enlarged illustration, in accordance with an exemplary embodiment. With screws  21 , the swivel body  3  is mounted to a split bushing  13 . The split bushing  13  is retained on the wired mounting sub  4  with the aid of binding clips  12 . For connecting the swivel body  3  to the wired drill string during a drilling operation, an electrical cable  16  is guided through the split bushing  6 . Above the electrical swivel body  3 , a bearing mount unit  9  is mounted rotatably to the split bushing  13 . A synchronizing system  14  connects the bearing mount unit  9  and the swivel body  3  in a torque-proof manner to each other so that they may rotate relative to the wired mounting sub  4  only jointly. A bar-shaped holder  10  projects radially outwards from the bearing mount unit  9 . The box  11  for the tripping sub  2  and the data cable housing sleeve  5  are affixed to the holder  10 . An input electrical cable  23  and an output electrical cable  17  run out of the swivel body  3  and run into the data cable housing sleeve  5  via a slip ring assembly located in an interior of the swivel body  3 , which is not illustrated here. The input electrical cable  23  and the output electrical cable  17  also run from there into the flexible part of the data cable housing sleeve  18 . The data cable housing sleeve  18  is attached to the data cable housing sleeve  5  via a socket plug connector  15 . During remodeling operations (e.g., tripping operations), the input electrical cable  23  and the output electrical cable  17  are galvanically connected to the wired drill pipe  6  via the tripping sub  2 . During the remodeling operations, the end of the wired mounting sub  4  is protected by a protection cap  26 . In order that the flexible part of the data cable housing sleeve  18  does not twist when the tripping sub  2  is being used, the flexible part of the data cable housing sleeve  18  ends in a device for compensating rotation  8  of the tripping sub  2 , using a socket plug connector  41 . 
       FIG. 3  and  FIG. 4A  show an exemplary embodiment of the tripping sub  2  in a perspective illustration, in each case partially sectioned. The tripping sub  2  comprises an essentially frustoconical external body  31  from which an axial running handle  39  for the manual axial guidance of the tripping sub  2  and three rotation handles  38  for manually rotating the external body  31  extend for easier handling during an insertion into the drill pipe. The external body  31  is configured such that it creates protection against the infiltration of drilling mud. The external body  31  is also constructed in an explosion-proof way. Furthermore, the device for compensating rotation  8  extends from the external body  31  in a rotatable way. The rotation  8  has already been illustrated above, on which the socket plug connector  41  may be seen. At a front face which faces the drill pipe of the external body  31 , an electrical detection switch  25  is arranged (see in particular detail D in  FIG. 4C ). The electrical detection switch  25  detects whether the electrical sockets  35  of the tripping sub  2  have been brought into contact with the electrical sockets of the drill pipe. The electrical sockets  35  may be designed as standard electrical sockets which end to the front face of the external body  31 , and the electrical sockets of the drill pipe extend axially in the form of contact pins. Electrical cables  42  run from the electrical sockets  35  through the interior of the tripping sub  2  to the socket plug connector  41 . A rotation blocking plug  34 , a collet  33  in the form of a clamping sleeve and a collet blocking plug  32  are arranged within the external body  31  in coaxial orientation thereto from the outside to the inside. 
     The collet  33  serves for fixating the tripping sub  2  in the drill pipe in an axial direction. For this purpose, the collet blocking plug  32  and the collet  33  are axially displaceable relative to each other between a locking position and a release position, with the collet  33  being divided in its front region into a plurality of tongues  33   b . The tongues  33   b  are radially movable in an elastic way and, at their free ends, exhibit projections  33   a  for interlocking with the drill pipe. In a collet position, the tongues  33   b  are extended radially. In a release position, they are retracted radially, as it is explained below in further detail. The collet blocking plug  32  has two indentations in the form of peripheral grooves  32   a  and  32   c , which are separated from each other by a web-shaped section  32   b  and receive the projections  33   a  of the collet  33  in two different release positions. 
     The collet  33  is axially mounted in a rigid way with regard to the rotation blocking plug  34  so that axial movements of the collet  33  and axial movements of the rotation blocking plug  34  take place jointly, whereby the rotation blocking plug  34  is unable to obstruct the radial movement of the tongues  33   b . As shown in  FIG. 4B , a buttress thread  37  comprises an external thread  34   c  on the peripheral surface of the rotation blocking plug  34  and an internal thread  31   a  on the interior surface of the external body  31 . With the buttress thread  37 , the rotation blocking plug  34  and the external body  31  are interconnected in such a way that the rotation blocking plug  34 , the collet  33  and the external body  31  are axially moved jointly in relation to the collect blocking plug  32  if the external body  31  is moved axially. However, in a rotary movement of the external body  31  in relation to the collet  33 , the external body  31  is movable axially in relation to the collet  33 . With two central springs  36 , the rotation blocking plug  34 , the collet  33  and the external body  31  are prestressed into such an axial position relative to the collet blocking plug  32  that the tripping sub  2  is located in the locking position in which the projections  33   a  of the collet  33  rest on the web section  32   b  of the collet blocking plug  32 . The two central springs  36  exert equal spring forces from opposite directions, whereby an equilibrium of forces is produced and results in the relative axial position. 
     The rotation blocking plug  34  serves for radially fixating the tripping sub  2  in the drill pipe. For this purpose, the rotation blocking plug  34  exhibits, at its front face, a sequence of projections  34   a  and indentations  34   b  which interlock with indentations and projections of a protective sleeve in the drill pipe, which are formed in a mirror-inverted fashion. In order to prevent that the collet  33  and the rotation blocking plug  34  twist with regard to the collet blocking plug  32 , a rotation blocking pin  43  is provided. As a result of this construction, the collet  33  and the rotation blocking plug  34  are secured radially and axially in relation to the drill pipe in the state of connection between the tripping sub  2  and the drill pipe. 
       FIG. 5  shows the arrangement of the collet  33  and the rotation blocking plug  34 . In this figure, the plurality of tongues  33   b  with the projections  33   a  and the front-end projections  34   a  and indentations  34   b  may be seen particularly well. For the sake of clarity, the external thread  34   c  on an outer surface of the rotation blocking plug  34  is not depicted graphically, but is annotated by reference numeral  34   c.    
     In the following, a process of connecting the tripping sub  2  to the drill pipe  6  is explained on the basis of  FIGS. 6A, 6B, 7-10, 11A, and 11B , and the subsequent loosening of said connection is explained on the basis of  FIGS. 12 and 13 .  FIG. 6A  shows an initial insertion of the external body  31  into a conical receiving space  71  of a box end  70  of the wired drill pipe  6 , with  FIG. 6B , detail A, showing an enlarged illustration of a cutout of  FIG. 11A . The drill pipe  6  comprises electrical sockets  73  (pins) for a galvanic connection to the electrical sockets  35  (e.g., bushings) of the tripping sub  2 . At the box end  70 , a sleeve-shaped connection element  72  is arranged. The sleeve-shaped connection element  72  comprises a ring-shaped lug  72   a  facing the tripping sub  2 , a ring-shaped indentation  72   b  formed behind the lug  72   a  as well as a conical central surface  72   c . When the tripping sub  2  is inserted axially with the aid of the axial running handle  39 , the tapered front end of the collet blocking plug  2  is axially centred through the central surface  72   c . Because of the prestressing by means of the central springs  36  as explained above (see, e.g.,  FIG. 4A ), the tripping sub  2  is located in a locking position in which the projections  33   a  of the collet  33  rest on the web-shaped section  32   b  of the collet blocking plug  32 . As a result, the projections  33   a  abut against the lug  72   a  of the connection element  72  of the drill pipe  6  during the insertion of the tripping sub  2 , whereby a further axial movement of the collet  33  is initially prevented. However, as shown in  FIG. 7 , the collet blocking plug  32  may move well further into the drill pipe  6  in the axial direction, whereby the web-shaped section  32   b  of the collet blocking plug  32  moves away from the projections  33   a  and the second peripheral groove  32   c  of the collet blocking plug  32  comes into alignment with the projections  33   a . As shown in  FIG. 8 , the peripheral groove  32   c  provides a free space necessary for an elastic radial inward movement to the tongue  33   b  with its projections  33   a  in that the lug  72   a  presses the projections  33   a  inwards. In this manner, the collet  33  may axially move further forward, while the projections  33   a  glide through underneath the lug  72   a  and reach the indentation  72   b  of the connection element  72 . As shown in  FIG. 9 , the indentation  72   b  provides free space for the projections  33   a , whereby the tongues  33   b  may move back into their radial starting position. When the axial insertion movement of the connection element  2  stops, the collet blocking plug  32  moves slightly back into its equilibrium position as a result of the prestressing by the central springs  36 , in which position the web-shaped section  32   b  again constitutes an abutment to the projections  33   a  so that they are prevented from a radial inward movement, whereby the locking position is taken, see  FIG. 10 . 
     As shown in  FIGS. 11A and 11B , using the rotation handles  38 , the external body  31  of the tripping sub  2  is rotated so that the electrical sockets  35  (e.g., bushing) of the tripping sub  2  come into an axial alignment with the electrical sockets  73  (e.g., electrical contact pins) of the drill pipe  6 . The fixation of the external body  31  in its axial position (i.e., against the spring pressure of pressure plates in the interior of the drill pipe  6 ) is performed with the buttress thread  37 . This position with galvanically connected electrical sockets  35  and  73  constitutes a working position connecting the connection element  2  to the drill pipe  6  during remodelling operations. 
     In order to loosen a connection between the drill pipe  6  and the tripping sub  2 , the above described operations are conducted in the reverse order. That means that at first, by rotating the external body  31  in the opposite direction, the axial fixation thereof has to be loosened. An interruption of the galvanic contact of the electrical sockets  35  and  73  occurs by loosening the axial fixation of the external body. By pulling the axial running handle  39 , the collet blocking plug  32  axially moves outwards in relation to the collet  33 , since the collet  33  is prevented from an axial movement because its projections  33   a  abut against the lug  72   a  of the connection element  72  of the drill pipe. As shown in  FIG. 12 , with a relative displacement between the collet blocking plug  32  and the collet  33 , the first peripheral groove  32   a  comes into alignment with the projections  33   a . As such, the projections  33   a  may be pressed radially inwards into the peripheral groove  32   a  by the lug  72   a , as shown in  FIG. 13 , whereby the locking of the collet  33  loosens and the latter may also be moved axially outwards in an unhindered fashion. 
     The exemplary embodiment of the tripping sub  2  according to an embodiment, as it has been described so far, is provided for the manual operation of the drilling facility by the operating staff. However, it is also possible to furnish the tripping sub  2  for a semiautomatic or fully automatic operation. 
       FIG. 14  shows an exemplary embodiment of the tripping sub  2  which is provided with a motor drive for rotating the external body  31 . A motor  53  rotates the external body  31  in relation to the collet blocking plug  32  via a gear comprising a pinion gear  51  on the driving shaft of the motor  53  and a gear ring  52  on the outer surface of the external body  31 . With external drives  50 , the axial movement of the external body  31  in relation to the collet blocking plug  32  is controlled. In some exemplary implementation, the external drives  50  are implemented as hydraulic or pneumatic cylinder-piston systems or as threaded spindles. The drives  50  are located on a rotation compensator device  40  to which also the socket plug connector  41  is attached. Also in this exemplary embodiment, an electrical detector switch  54  is provided which detects whether the external body  31  has been rotated into a correct angular orientation in relation to the drill pipe, in which a galvanic connection between the electrical sockets of the tripping sub and of the drill pipe occurs. The final fixation of the external body  31  by the external drives  50  occurs in this correct angular orientation. 
       FIG. 15  shows a furnishing of the tripping sub  2  with devices for automatically placing the tripping sub  2  on the drill pipe  6 , while it is being held by a grabber assembly  1 . For this purpose, the tripping sub  2  is accommodated in a housing  63  mounted on the holder  10  via actuator arms  61  and  62  and the holder  10  is fixed to the swivel body  3  via the bearing mount unit  9 . The wired mounting sub  4  extends from the swivel body  3 . The actuator arms  61  and  62  are guided to and from the drill pipe  6  by actuators  60  in a three-dimensional movement. The housing  63  has a conical open end which facilitates the placement on the drill pipe  6  in a centred orientation. Distance meters may also be used for a more precise placement.