EP0811745B1 - Steering device for a directional drilling tool - Google Patents

Description

The invention relates to a control device for a directional drilling tool, in particular for drilling work with a coiled tubing as drill pipe, in an education according to the preamble of claim 1.

In a known control device of this type (US-A-5 311 952) comprises the orientation device a stepper that is driven by the drilling fluid whose pressure is changed by reducing the pump pressure when the stepping mechanism is to be operated.

In a further known control device of the type mentioned (US-A-5 215 151) the orientation device comprises a tubular differential piston, which can be actuated by the drilling fluid in the event of an axial displacement through a screw-type motion converter gear into a rotary motion is offset and the second outer housing part carrying the directional drilling tool issued a corresponding rotary movement.

A further known control device (US-A-5 339 913) comprises two outer housing parts, which can be telescopically extended and retracted relative to each other, with a helical-motion converter transmission between the telescopic parts the outer housing part carrying the directional drilling tool Imparted rotational movement.

In the case of a control device with housing parts which can be rotated relative to one another (WO-A-8002582) is a lower housing part opposite the upper housing part provided electric motor pivoting for orientation purposes, the in line with another electric motor synchronized with this Performing movements and this on a gear on the lower Transmits part of the housing. Common to the previously known control devices is that the measuring and control device is arranged below the orientation device.

If a reorientation of the directional drilling tool in the known control units essential operating parameters change such as the pressure of the rinsing liquid or the weight load of the Drill bits with which a change in the twist of the winding tube is accompanied by another change when drilling operations resume experiences. This makes the orientation process time-consuming in practice because he is exposed to various disturbances, the tedious trial inevitable do.

The invention is concerned with the problem of creating a control device that an alignment of the directional drilling tool which is impaired by fewer disturbance variables allowed. The invention solves this problem with a control unit the features of claim 1. With regard to further refinements referred to claims 2 to 21.

The control device according to the invention enables with its drilling operation independently actuable electric motor drive of the orientation device a quick and precise execution of an orientation process with continued drilling operations and thus avoiding changes in the twisting of the drill pipe string.

The arrangement of the measuring and control device in the first outer housing part between the orientation device and the connecting part for the drill pipe reduces the frictional resistance of the extremely short second Outer housing part considerably during orientation processes, so that this with higher precision and at the same time lower performance can be carried out. It also avoids cable entries through the orientation device therethrough. If the drilling tool gets stuck in the borehole and try to pull it open to a usually in the range between the first and the second demolition part entering demolition, then belongs to the expensive measuring and Control device for the salvable parts of the drill.

Fig. 1

einen schematischen, vereinfachten Längsschnitt durch ein Steuergerät nach der Erfindung, und

Fig. 2

eine abgebrochene Schnittdarstellung ähnlich Fig. 1 einer zweiten Ausführung des Steuergeräts nach der Erfindung.

Further details and effects of the invention result from the following description of two exemplary embodiments of the object of the invention, which are illustrated in more detail in the drawing. The drawing shows:

Fig. 1

a schematic, simplified longitudinal section through a control device according to the invention, and

Fig. 2

a broken sectional view similar to FIG. 1 of a second embodiment of the control device according to the invention.

The control device for a directional drilling tool illustrated in FIG. 1 comprises in particular a tubular outer housing 1, the first, one not shown outer casing part 2 and a second, this immediately adjacent, a directional drilling tool, not shown facing outer housing part 3 comprises. Encloses the outer housing 1 an orientation device designated as a whole by 4 and one Measuring and control device 6, the transducer part 7, an electronic Measured value processing part 8 and an electronic control part 9 May include separately, but instead also together in one housing section can be accommodated. Measuring and control devices suitable training is generally known and does not require any here detailed explanation.

The first outer housing part 2 has a connection part 10 for the connection a drill pipe, in the present case to a winding pipe, which one into the winding pipe end engaging hollow pin part 11 and as a connecting means Union nut 12 includes. The connection between the control unit and the winding tube can be done without prior orientation of both parts. The torque is transmitted by friction, which is generated by the union nut 12. The hollow pin part 11 surrounds an electrical quick connection device 13, which is intended to provide an electrical connection of the measuring and Control device 6 with an electrical housed in the winding tube Manufacture pipe system. The quick electrical connection device 13 is supported against rotation, has a central channel 14 for receiving electrical lines 15 and is at its lower end with the stationary Provided part of an electrical rotary transmission device 16, the rotating part associated with the upper end of the measuring and control device 6 is.

The second outer housing part 3 has a connection part 17 for example a screw connection with the outer housing of a directional drilling tool on and comprises a shaft portion 18 which means in the first outer housing part 2 Bearing 19, 20 about the longitudinal central axis 21 of the first outer housing part 2 is rotatably mounted and in operative connection with the orientation device 4 stands.

The first outer housing part 2 surrounds the measuring and control device 6 below Leave an annular gap 22 for the implementation of drilling fluid, the surrounding the upper part of the orientation device 4 Annular gap 23 continues. The annular gap 23 stands over a transfer channel 24 with a central drilling fluid channel 25 in the lower part of the orientation device 4 in connection, in a corresponding central drilling fluid channel 26 merges into the shaft part 18 of the second outer housing part 3.

The orientation device 4 has a drive source for actuating movements an electric motor 27, which operates the second outer housing part 3 activating intermediate drive in action. The electric motor 27 is preferred designed as a brushless three-phase AC motor that 1 reversible in the drive direction in the embodiment of the control device according to FIG is formed and a hydraulic pump working in reverse operation 28 drives. The hydraulic pump 28 are on the outlet side control valves a control valve block 29 downstream, which the application of Determine hydraulic lines 30,31.

The hydraulic line 30 opens into an annular, from the first outer housing part 2 bounded cylinder chamber 32 in which an annular adjusting piston 33 is guided axially. The actuating piston 33 is by means of a screw thread guide in its axial displacement in a rotary movement around the Longitudinal central axis 21 of the first outer housing part 2 is displaceable and transmits this rotary movement on a drive shaft 34 for the second outer housing part Third

In detail, the adjusting piston 33 is helical on its outer circumference Guide grooves 35 provided in the inside of the first Engage outer housing part fixed sliders 36, the axial displacement of the adjusting piston 33 to give it its rotary movement. On its inner circumference the actuating piston 33 is provided with an axial multi-spline profile 37, that with corresponding axial grooves 38 on the outer circumference of the drive shaft 34 cooperates.

When hydraulic line 30 is pressurized and depressurized Hydraulic line 31 is given a downward movement to the actuating piston 33, during the actuating piston 33 when the hydraulic line 31 is pressurized and depressurized hydraulic line 30 performs an upward movement. For this purpose, the hydraulic line 31 is along the drive shaft 34 up to one Inner annular space 39 guided in the actuating piston 33, the inside of the drive shaft 34 is limited, which extends axially through the adjusting piston 33.

A compensation chamber 40 is provided above the electric motor 27 is delimited on the upper side by a compensating piston 41. The compensation chamber 40 is designed as an annular chamber, on the outside of a tubular carrier housing 42 and on the inside of a tube part 44 'of a housing block 44 limited, which receives the electric motor 27. This housing block 44 will enclosed by the carrier housing 42, which above the compensating piston 41 with passage openings for making a connection of the compensation chamber 40 to the annular space 23 through which drilling fluid flows is.

For the sake of completeness, it is pointed out that the compensating piston 41 relative to the carrier housing 42 and the tubular part 43 of the housing block 44 through seals 46 and 47, the drive shaft 34 in its upper Area opposite the first outer housing part 3 by a seal 48, the actuating piston 33 relative to the drive shaft 34 through a seal 49 and opposite the first outer housing part 2 by a seal 50, and the Shaft part 18 of the second outer housing part 3 opposite by a seal 51 the first outer housing part 2 is sealed.

The drive shaft 34 is in the region of its upper end part, that of the control valve block 29 adjoins, connected to the support housing 42 and supports this Carrier housing 42 together with the parts connected to it can also be rotated, so that from the actuating piston 33 to the drive shaft 34 during an orientation process transferred rotary motion synchronously to the second outer housing part 3 and the associated directional drilling tool, but also on the Main part of the orientation device 4 and the associated measuring and Control device 6 is transmitted. Despite the arrangement of the measuring and control device 6 above the orientation device 4 is thus ensured that the measuring and control device 6 changes the position of the directional drilling tool can record and evaluate as a result of an orientation process and is accordingly involved in the orientation process.

For the electrical connection of orientation device 4 and measuring and Control device 6 serves a quick connect device 55, which at the end of the housing block 44 is arranged and via the electrical contact part 56 the electrical supply of the electric motor 27 and the control valves in Control valve block 29 produces.

After an orientation process has been carried out, the actuating piston 33 hydraulically in its respective position by means of the control valves in the control valve block 29 be locked. However, it is also conceivable to twist the Drive shaft 34 and thus the outer housing parts 2 and 3 through each other a braking or blocking device (not shown) to prevent the between the second outer housing part 3 and the drive shaft 34 is effective.

Fig. 2 illustrates a second embodiment of an inventive Control device in a similar to the illustration in FIG. 1, but broken off Representation of the part of the orientation device 104 first outer housing part 2. As can be seen in FIG. 2, includes the orientation device 104 an electric motor 127, the drive shaft 26 acts on a planetary gear 58, the output shaft 59 of the bearing part 18 of the second outer housing part 3 drives. An eight-stage is preferred Planetary gear 58 is provided which has a reduction ratio of e.g. 4400: 1 and accordingly the speed of the output shaft 59 of Electric motor 127 from e.g. Reduced 1500 rpm to about 0.34 rpm.

In particular, the orientation device 104 comprises a housing block 144, which has a tubular basic shape and the winding 60 of the electric motor 127 receives and the rotor forming a drive hollow shaft 26 the electric motor 127 is supported in bearings 61 and 62 and at the same time itself is rotatably supported by a bearing 63 in the first outer housing part 2. The Output shaft 59 of the planetary gear 58 has one through the hollow drive shaft 26 of the electric motor 127 extending part 59 ', which is connected to the housing block 144 above the electric motor 127. Accordingly, the housing block 144 can be rotated with the output shaft 59 connected. The output shaft 59 of the planetary gear 58 is at 64 with connected to the bearing part 18 of the second outer housing part 3, e.g. screwed, and is together with this bearing part 18 on bearings 65, 70 and 71 supported rotatably with respect to the first outer housing part 2. Between the Bearing part 18 of the second outer housing part 3 and the first outer housing part 2, a sprag freewheel 57 is provided, through which the reaction torque of the directional drilling tool directly onto the first outer housing part 2 and transmitted over this into the drill string, so that the through the Electric motor 127 unlimitedly rotatable orientation device 104 of reaction moments of the directional drilling tool is free.

The housing block 144 has a part 144 ', which is no longer on its illustrated end with a quick connector 55 of one embodiment 1, the measuring and control device 6 wear and with this one of the electrical quick connector 55 corresponding device can be electrically connected. In which the Measuring and control device 6 adjacent area is part 144 'of one Annular space 71 corresponding to the annular space 22, the passage channels 72 is connected to a central drilling fluid channel 73. The central bore flushing channel 73 in the part 144 ′ of the housing block 144 finds an extension 74 in the output shaft 59,59 'of the planetary gear 58 and an extension 75 in the second outer housing part 3, so that the supply of the directional drilling tool is secured with drilling fluid.

2 also ensures that orientation processes by operating the electric motor 127 regardless of the drilling operation can be made, even here despite the arrangement of the measuring and Control device 6 ensured above the orientation device 104 is that the measuring and control device 6 with synchronous rotary movements executes the second outer housing part 3 aligning the directional drilling tool. The electric motor 127 can only in one direction in this embodiment be operated because the reversing operation is blocked by the sprag freewheel is.

Basically, it should be noted that the outer housing 1 with its parts 2 and 3, the shafts 34 and 59 and basically all tubular components of the control unit each axially connected to one another, in particular screwed sections can exist, as is the case with tubular components of drilling equipment is the norm.

The part 144 ′ of the housing block 144 faces the measuring and control device 6 towards a central feed-through channel 76, which is located in an off-center Channel 77 continues into the area of the winding 60 of the electric motor 127 extends and serves the electric motor 127 with the measuring and Control device 6 to record electrically connecting lines.

The embodiments of the control device illustrated in FIGS. 1 and 2 according to The invention combines the advantages of a fast and precise Carrying out the orientation process with continued drilling operations and those advantages resulting from an arrangement of the measuring and control device 6 result above the orientation device. The measuring and control device However, 6 can also be used in any embodiment of an orientation device can be provided above this in the first outer housing part, for example such orientation devices as used in the prior art are known and have been described in the introduction.

Claims (21)

1. Control equipment for a directional drilling tool, particularly for use in drilling operations using an enveloping tube as the drilling tube, having a tubular outer casing (1) which contains a position-locating device (4) and a measurement and controlling device (6) together with a measured value recording element (7), an electronic measured value processing unit and a control unit (9) and a first outer casing part (2) which can be connected to the bore-hole end of the drilling tube by a connection unit (10) together with a second outer part (3) which is directly adjacent axially to the first casing part (2) which is capable of rotating around the longitudinal axis (21) of a bearing (18) in the latter and which can be made to rotate by the position-locating device (4, 104) attached to the first outer casing part (2) and which can be connected by means of a connection unit (17) to the directional drilling tool, characterised in that the measurement and controlling device (6) is arranged above the position-locating device (4, 104) in the first outer casing and can be driven synchronously by the drive (27, 127) of the position-locating device (4, 104) with the second outer casing part (3) and that the drive for the position-locating device (4, 104) takes the form of an electric motor (27, 127) which when in operation impels an intermediate drive which actuates the second outer casing part (3).
2. Control equipment in accordance with claim 1, characterised in that the electric motor (27, 127) is designed as a brushless, three-phase alternating current motor.
3. Control equipment in accordance with claim 1, characterised in that the armature of the electric motor (27, 127) forms an inner-lying, hollow drive shaft (26).
4. Control equipment in accordance with one of claims 1 to 3, characterised in that the electric motor (27) is designed to provide a reverse drive direction and that when in reverse it drives a hydraulic pump (28) which impels via control valves an adjustable displacement piston (33) which can be displaced axially between two end-positions and which can be made to rotate by a threaded guide (35, 36) and impart a rotating drive to the bearing part (18) of the second outer casing part.
5. Control equipment in accordance with claim 4, characterised in that the threaded guide (35, 36) is located between the first outer casing part (2) and the adjustable displacement piston (33) and the adjustable displacement piston drives a co-axial drive shaft (34) for the second outer casing part (3) by means of spline shaft teeth or a feather key connection (37, 38).
6. Control equipment in accordance with claim 5, characterised in that the drive shaft (34) passes through the adjustable displacement piston (33) co-axially and rotates the measuring and controlling device (6) above the position-location device in the first outer casing part (2) synchronously with the second outer casing part (3).
7. Control equipment in accordance with Claim 6, characterised in that at its end facing the connection unit (10) of the first outer casing part (2) the drive shaft (34) supports a tubular housing (42) which contains the electric motor (27), the hydraulic pump (28) and the control valve block (29) of the position-locating device (4).
8. Control equipment in accordance with claim 6 or 7, characterised in that the position-locating device (4) supports the measuring and controlling device (6) at the facing end and is electrically connected to the latter by a rapid-action electrical connection device (55).
9. Control equipment in accordance with one of claims 4 to 8, characterised in that the adjustable displacement piston (33) can be hydraulically locked in its current position by means of the control valves.
10. Control equipment in accordance with one of claims 4 to 9, characterised in that the measurement and control equipment (6) and the upper part of the position-locating device (4) delimit with the outer casing part (2) an annular space (22, 23) through which the drilling mud can pass.
11. Control equipment in accordance with claim 10, characterised in that the drive shaft (34) actuated by the adjustable displacement piston (33) and the second outer casing part (3) together delimit a central drilling channel (25, 26) which is connected with the annular space (23) in the outer casing part (2) through a connecting channel (24) in the upper end of the drive shaft (34).
12. Control equipment in accordance with one of claims 1 to 3, characterised in that the drive shaft (26) of the electric motor impels a multi-stage planetary gear (58), the driven shaft of which (59, 59') drives the second outer casing part (43).
13. Control equipment in accordance with claim 12, characterised in that the driven shaft (59) of the planetary gear possesses an element (59') which extends through the drive shaft of the electric motor and through the latter itself.
14. Control equipment in accordance with claim 12 or 13, characterised in that the driven shaft (59) with its element (59') which passes through the electric motor (127) of the position-location device (104) drives the measuring and control equipment supported by the position-locating device (104) in the first outer casing part (2) synchronously with the second outer casing part (3).
15. Control equipment in accordance with claim 13 or 14, characterised in that the driven shaft (59) of the planetary gear (58) and the second outer casing part (3) commonly delimit a central drilling mud channel (74, 75).
16. Control equipment in accordance with one of claims 12 to 15, characterised in that the position-locating device (104) comprises a tubular housing block (144) which is mounted in the first outer casing part (2) so as to be capable of co-axial rotation with it and which supports the winding (60) of the electric motor (12).
17. Control equipment in accordance with claim 16, characterised in that the measurement and control equipment (6) is supported on the housing block (144) of the position-locating device (104) in a manner which prevents it from rotating.
18. Control equipment in accordance with one of claims 12 to 17, characterised in that the driven shaft (59) of the planetary gear (58) is coupled to the housing block (144) of the position-locating device (104) in an area above the winding (60) of the electric motor (127).
19. Control equipment in accordance with one of claims 1 to 18, characterised in that the measuring and control equipment (6) possesses at its end facing away from the position-locating device (104) an electrical rotary motion transmission device (16) providing an electrical connection with a non-rotating, supported part of an electrical rapid-connection device (13).
20. Control equipment in accordance with claim 19, characterised in that the connecting element (10) on the first outer casing part (2) comprises a guidance element (11) which penetrates into the end of an enveloping tube and which grips the contact feature of the electrical rapid connection device (13), together with a locking nut (12) as a securing element.
21. Control equipment in accordance with one of claims 12 to 20, characterised in that the bearing part (18) of the second outer casing part (3) is conjugate with an automatic switching clutch (57) which transmits the reaction moment of the directional drilling tool to the first outer casing part (2).

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