Device for connecting electrical lines for boring and production installations

Device for connecting electric lines for drilling and Produktionsanlaqen

The invention relates to a device for connecting electrical cables to be screwed together, substantially tubular connecting elements of drill pipes.

A key element in modern oil, gas or geothermal drilling is the data acquisition during drilling. The same is also true for the construction of the well and the subsequent oil, gas and hot water production. Only by capturing the respective, relevant variables can be drilled safely, efficiently and economically operated mixed. However, a problem arises with the Echzeitdatenübertragung of measured data to the surface of the rig. From several kilometers below the data with a high data rate (eg 200kBaud) to be transferred.

Currently, steel radiators are used without cabling to drilling part. The tubes are screwed in regular intervals (eg 9 meters). Thus arises a several-kilometer-long drill pipe, at the end of the drill bit is. Inside the pipes, the drilling fluid (mud) is fulfilled the many functions during drilling. One of these functions is known in the art, the transmission of data by means of pressure pulses. Since this communication is very slow (eg 10 baud) were amplified wanted procedures that other transfer mechanisms use (Sonar, flows via the ground etc.). The most efficient solutions have shown, which are connected to a wiring of the drill string (electricity, lighting, etc.). Once the drill string is connected by means of electrical cable or conductive layers, high-speed data transmission is possible.

Two methods are possible in principle. Some prototypes work with galvanic connections between the individual tubes of the boom. Partially commercially available systems use a magnetic coupling between the pipes. The currently used magnetic coupling only allows data transmission.

The intention to rewire a drill string encounters several problems simultaneously.

Steel tubes have to be manufactured or retrofitted with heat-resistant, Mud-resistant, pressure-resistant cables without the carrying capacity of the drill string and the staff affected when screwing the tubes will suffer.

must To facilitate data transmission in the drill string, the problem of electrical

Connection between the pipes to be solved. The electrical connection must be reliable, simple and robust made in the mechanical connection of the tubes (rotating movement) produced. To bring the greatest challenge an electrical connection is made, can transmit the power and / or data, is the screw movement during the bolting process of each drill pipe (pipes). In addition, the drilling process, high pollution and all types of liquids, a harsh environment. This challenge to be overcome in order to develop a successful, functioning system.

this object the type mentioned above is achieved with a device characterized in that on one connecting element a first electrical contact element is fixed and that the other connecting element is a second electrical contact element is arranged slidably in the direction of rotation of the connecting element.

The construction solves the problem that two components of movement to occur during the screwing of the two connecting members, namely, a circumferential and an axial direction in the connecting elements. Due to the fact that one of the two contact element in circumferential direction is movable, it can rotate with the other connecting element in the production of electrical or galvanic connections between the two contact element, so that the two connecting elements are connected to each other only through the axial movement component have to.

In a preferred embodiment of the invention the movable contact member is disposed at a connecting element rotatably mounted on the ring, said ring preferably an outer ring of a grinding ring. Slip rings are in electrical proven and robust components that can be used also in the present case, to compensate for the rotating movement component during the connection of the two connecting elements.

The solution presented is suitable for data and power transmission in the drill string based on cabled pipes (eg steel or CFRP and GRP pipes) whose wiring is electrically connected to the pipe ends.

The wiring can be carried out with a two-wire, heat-resistant voltage supply cable, which is laid in a protective tube (chemical resistance). On the surface of both electrical power and data can be fed in this cable. In the case of the rotating drill string, this is done with slip rings. In the pipe, this cable is directed to a connecting element which establishes a good conductive connection to the next tube.

For the supply of energy preferably DC voltage can be used in the mains voltage range. The adaptation to all possible distribution networks is carried out once centrally before being fed.

In addition to data communication can (etc. Modem, Repeater, transceiver) occur, the problem of power supply of the data transmission elements. As the drill string _ O _

can be several kilometers long (eg 20 km) is the problem of data transmission over long lines to solve. High speed data transfers (eg fieldbus systems) are suitable only for some 100 meters without repeaters. However, the use of many Repeatem requires an adequate power supply. This is problematic due to the voltage drops over long distances and many repeaters. Although the installation of batteries in the repeater solves the problem of energy transfer, but leads to unmaintainable bad, unreliable systems (battery replacement, battery failure). Quite problematic is the installation of repeaters in the drill string due to lack of space.

To solve the problem is proposed in the invention that the electrical lines have a power-line communication is connected.

For the supply of data by means of a power-line communication, a narrow-band OFDM (orthogonal frequency divison multiplex, multicarrier) processes are used. This method is also known as "Power Line Communication (PLC)". Modems that are using this method currently in electric power networks for remote maintenance or remote meter used (Distributed Line Communication, DLC). It succeeds so over conventional power lines without additional cabling information for several kilometers without repeaters with data rates of a few hundred Kilobaud exchange.

With such a modem, the data are modulated onto the voltage supply in a plurality of carrier frequencies, is fed with slip rings in the drill string and transmitted in the rotary drill string by the connecting elements at the pipe ends for receiving location (consumer, electronic measuring system) in the borehole. Several such modems can not only save energy but also data received or send by the connected power supply.

Advantages of this problem-solving include the fact that no separate wiring for data communication is necessary by using the PLC modulation. This solution is therefore economically. For the desired Bohrstranglänge (about 20km), no repeaters are needed, which dissolves space and energy problems. Since no separate data cabling is necessary, the need for additional electrical contacts to the pipe joints. Since no repeaters are needed, the necessary amount of energy is reduced such that 4-6 mm at an economical choice of necessary conductor cross section (eg,²) A supply voltage (eg 400V) is sufficient to provide the required power (eg 200W) to a 20km distant consumers bring.

The presence of a permanent power supply allows the cooling of electronic systems in the drill string, thereby allowing a greater depth (temperature coefficient in the bore about 3.3 ° C / 100m) or longer stay. Energy and data Supply allows a range of new applications. A limitation of the supply voltage, for example 400V allows the choice of a standard cable (such as 240 / 400V), and reduces the required insulation distances in the mechanical design of the system components as compared to high-voltage systems.

Further preferred embodiments of the invention are subject of the remaining dependent claims.

Further features and advantages of the invention will become apparent from the following description of a preferred embodiment of the invention with reference to the drawings.

It shows:

FIG. 1 shows an embodiment of an inventive device in a explosionsartigen-

Illustration, FIG. 2 shows the device in the assembled state in cross section,

Fig. 3 shows a detail of the device from Fig. 2 in an enlarged scale,

Fig. 4 shows a part of the device according to the invention

Fig. 5 shows a detail from Fig. 4 in an enlarged scale,

Fig. 6 shows a farther portion of the device according to the invention, Fig. 7 another part of the device according to the invention

Fig. 8 shows a part of the device according to the invention in an exploded view,

Fig. 9 is a section through part of the device according to the invention,

Fig. 10 is a section through another part of the device according to the invention,

FIG. 11 is a drill pipe with a box and a pin and Fig. 12 shows a detail of the box on the drill pipe of FIG. 11.

In Fig. 1, an embodiment of a device according to the invention is shown, which serves for connecting drill pipes 32, for example, of drill strings in drilling rigs. The inventive device comprises a first connecting element 1, which is referred to as "pin", and a second connecting member 2, which is referred to as "Box" on. The pin 1 and the box 2 are connected in a manner not shown with drill pipes 32, which may for example be made of steel, carbon fiber or fiberglass. The inner diameter of the pin 1 and the box 2 corresponds substantially to the inner diameter of the drill pipes 32, whereas the outer diameter of the pin 1 and the box 2 is larger than the outer diameter of the drill pipe 32 is.

At pin 1 a slip ring 3 and a catch ring 4 are rotatably received, which are surrounded in the assembled state of an outer ring fifth The diameter of the outer ring 5 is slightly larger than the diameter of pin 1 and box 2 and made of a wear-resistant material, so it can serve as a wear part which easily replaced can and the pin 1 and the box 2 protects against excessive wear. At its the box 2 facing the end of 6, the pin 1 has a conically tapered outside diameter with an external thread on. The box 2 has in contrast to its pin 1 end facing 7 on a conically widening inner diameter with the same cone angle and an internal thread. The pin 1 and the box 2 can be screwed in this way by a few rotations over a relatively large length to each other.

The slip ring 3 is composed, as Fig. 8 shows, in detail, of an inner ring 8 which is arranged on the pin 1, and an outer ring 9, which is rotatable in peripheral direction relative to the inner ring 8. In the axial direction of the outer ring 9 is fixed against the inner ring eighth The slip ring 3 is - apart from subsequently still explained details - constructed known otherwise as per se from the prior art.

At the outer ring 9, two electrical contact elements are arranged in the form of contact pins 10 which are electrically connected to the brush of the outer ring 9 in the illustrated embodiment. It may be present at the slip ring 3 the same number of pins 10 as sliding contacts. But it is also possible to provide a particularly reliable electrical connection, the sliding contacts provide also for example two pins 10th Alternatively, it is also possible, by default provide more sliding contacts as contact pins 10 to the possibility of further electrical connections between the pin 1 and the box 2 to make it available as needed.

In Figs. 5 and 6 of the catching ring 4 is shown in more detail. He has in the illustrated embodiment four through openings 11 for contact pins 10th He also has the slip ring 3 side facing receptacles 12 on (in the illustrated embodiment, eleven receptacles 12) for compression springs 13, which are supported on the end face 14 of the outer ring. 9 The compression springs 13 are fully incorporated into the receptacles 12 in the compressed state. On the record 12 or springs 13 opposite side a catch pin 15 is slidably supported in the axial direction against a compression spring, not shown on the muzzle ring. 4 On the same side on which the pilot pin is 15, the openings 11 are closed by a seal 16, which can be penetrated by the contact pins 10, however, and 10 through openings 11 and closes again after the retraction of the contact pins.

On the outer circumference of the catch ring 4 is formed on the slip ring 3 side facing a bead 17, a sealing ring 18, for example an O-ring arranged. The outer ring 5 is screwed via a thread 21 with the pin 1 and of the catch ring 4 is located with its sealing ring 18 on the inner side of the outer ring 5 sealingly engages. At pin 1 a groove is further still 19 arranged in the area under the catch ring 4, in which a sealing ring 20, for example an O-ring is located, which also rests sealingly against the inside of the catch ring 4th Through the thread - S -

21 and the sealing rings 18 and 20, the space in which the slip ring is 3, are sealed.

On the catch ring 4 side facing the box 2 on the one hand a catch opening 22 for the catch pin 15 and on the other contact elements in the form of two contact bushes 23. Since only two pins 10 are used in the illustrated in the drawings embodiment, only two contact sockets 23 are available. In addition to the two contact sockets 23 two further seats 24 are still arranged, which can be equipped as needed with contact sockets 23rd In Fig. 3 it can be seen that the contact sockets 23 and the recordings 24 are also closed by a seal 25, which can be penetrated by the contact pins 10 also and the contact sockets 23 to reseal after the retraction of the contact pins 10. The seal 25 is not shown in Fig. 7.

The seals 16 and 25 are perforable seals and may for example be made of rubber and provided from the outset with a perforation, which facilitates penetration and withdrawal of the contact pins 10, however, which must be ensured that the seals 16 and 25 without contact pins 10 are so dense that no spark or arc skip or can be ignited when the contact pins 10 or contact bushes 23 are under tension, to minimize any risk of explosion. In addition, the seal must prevent the risk of contamination and the penetration of various liquids under the harsh conditions of a drilling process.

In FIG. 9 is a section of the box 2 is shown in which a first angle leading from inside the box 2 to the outside hole facing 26 and further comprising a branching off, expressed in axial bore can be seen 27, which lead to recesses 28 in which the female contacts 23 are accommodated. Through these holes 26 and 27 and, optionally, an unillustrated knuckle, the contact sockets 23 can be connected to a linkage arranged in the interior of the tubes 32 line. In Fig. 10 a section through the pin 1 in which a bore is to be seen 29 that leads from the inside of the pin 1 to the slip ring is not shown in this drawing. In this manner, a arranged in the interior of a drill pipe 32 conduit, optionally connected via a subsequent inside of the pin 1 to the bore 28, not shown, elbow, with the sliding contacts of the inner ring. 8

Typically, a pin 1 and at the other end a box 2 will be located on a drill pipe 32 at one end, with the respective contact elements (pins 10 and female contacts 23) are connected to each other via the running in the interior of the drill pipe 32 electrical line. one along the entire drill string extending, out continuous electrical line can thus be made by screwing together of drill pipes 32 each have a pin 1 and a box. 2 The screwing of Pin 1 and Box 2 is carried out according to the invention as follows. In separate state of Pin 1 and Box 2 of the catch ring 4 is pressed by the compression springs 13 so far from the outer ring 9 away that its bead 17 or its sealing ring 18 rests against an inwardly projection 30 of the outer ring. 5 Since the outer ring 9 is axially immovable, the tips of the contact pins 10 are pulled so far in catching ring 4 inside that they are behind the seal 16 and not penetrate through. If the box 2 placed over the tapered end 6 of the pin 1 and thereby rotated to screw the box 2 to pin 1, the Box 2 comes with its end face 31 initially in contact with the catch pin 15 against the force of its compression spring is pushed backwards into the catch ring 4 and engages the catch bore 22 at the latest after one complete revolution of the box. 2

From that moment on 9 rotated by the box 2 and the catch ring 4 and the contact pins 10 of the outer ring. Once the thread between pins 1 and Box 2 begins to grip the catch ring 4 is constantly pressed against the outer ring 9 until it rests completely against him. During this movement the tops pilot pins 10 initially begin the seal 16 and the seal 25 to penetrate subsequently until they penetrate into the contact sockets 23 and make an electrical connection. Since the catch ring 4 and the box are 2 aligned by the pilot pin 15 in the circumferential direction exactly one another, an exact occurrence of the contact pins 10 is also ensured in the contact sockets 23rd

If the connection between Pin 1 and Box 2 is separated again, is pressed during unscrewing of Pin 1 and Box 2 of the catch ring 4 by the compression springs 13 from the outer ring 9 away, so that the contact pins 10 are pulled out of the contact sockets 23rd The compressive force of compression springs 13, therefore, must be so large that both the friction of the contact pins 10 in the contact socket 23 and the seals 16, 25 as well as the friction of the seal rings 18, 20 can be securely overcome. The length of the contact pins 10 and the travel of the catch ring 4 are coordinated so that the catch ring 4 only triggers from the end face 30 of the box 2 when the contact pins 10 is retracted so far that they, the seals 16, 25 no longer penetrate, so that a safe separation of pin 1 and box 2 is ensured.

The construction solves the problem that two components of movement to occur during the screwing of the two connecting members, namely, a in the circumferential direction and one in the axial direction of the connecting elements. Due to the fact that one of the two contact element in circumferential direction is movable, it can rotate with the other connecting element in the production of electrical or galvanic connections between the two contact element, so that the two connecting elements are connected to each other only through the axial movement component have to. The compensation of the relative movement of the pin 1 and the box 2 for the production of the electrical connection during the tightening process can also be performed in other ways. Essential is the resolution of the degrees of freedom of movement between the pin 1 and the box 2 during the screwing in the circumferential and axial directions. It must by an institution of the position of a contact element 10, for example, the plug position in the Pin 1, with the position of the other contact element 23, for example, the female position in the box 2, while the screw are aligned such that the electrical contact pins in the electrical sockets make. This can preferably but not necessarily take place over sprung or electrical or magnetically activated pilot pins 15, which are placed on pin 1 or 2 and the box to ensure a positioning of the contact pins during Verschraubprozesses circumferentially.

In Fig. 11 is shown a drill pipe 32, on which at one end a pin 1 and a box at the other end 2 are arranged. In the illustrated in Fig. 11 embodiment, the drill pipe 32, the pin 1 and the box 2 are made in one piece, which is a possible embodiment. Usually the drill pipe 32, the pin 1 and the box 2 but be separate components that are fixed to each other.

To relocate an electrical conduits within the drill pipe 32, in one embodiment of the invention within the drill pipe 32, a conduit 33 may be arranged, which on elbows 34, 35 to the pin 1 and the box 2 and the therein holes 26, 29 are connected. In the bores 26, 29 fittings 36 are used which seal the bores 26, 29 on tapered shoulders 37 against the inside of the drill pipe 32nd In these fittings 36, the elbows 34, 35 are screwed tight.

One or more electrical lines can be laid in this way from pin 1 to Box 2, without coming into contact with the washing liquid present inside the drill pipes 32nd

The electrical connection can be produced for example by means of slip rings, wherein the electrical transmission between the outer ring and inner ring by means of balls (such as a ball bearing), or by means of two on each other abrasive metal rings (such as a bearing) or can be done by means of electrical brushes.

but it is also possible to use a cable to compensate for the rotational movement, which is for example on a cable drum, which is provided with a spiral or helical spring wound. It would, for example, also possible to use a spiral or coil spring itself as electrical conductor, which compensates for the relative movement between the movable contact member and the pin 1 or Box2.