EP0845576A2 - Drill string - Google Patents

Abstract

The borer comprises a multi section structure with a boring head to drive the bore to the target point. The boring head is fitted with a grip, attached via a swivel mounting to pull the pipeline back to the start position. The boring head widens the bore during the retraction process and clears debris from the bore. The boring sections are gripped by a chuck to pull each section back to the start point. The swivel grip ensures a low friction drag for the pipeline with reduced risk of damage. The chuck is operated by a polygonal drive for rapid deployment.

Description

I. Field of application

The invention relates to a drill pipe as it is used to drill holes in Soil over a long distance, and preferably for the introduction of so-called Horizontal drilling is used.

II. Technical background

With the help of a horizontal drilling machine, the hole is flat, sloping or even introduced horizontally into the ground, to supply lines etc. at a certain depth below the surface of the earth from point A to point B. embarrassed.

The specialty of such horizontal bores compared to vertical bores consists of an open shaft as the end point for a horizontal bore or another accessible point is approached so that the retraction of the Pipeline in the borehole not in the forward but in the reverse direction of the Drilling progress is made. After completing the drilling, that is under Leave the boring bar in the borehole, the previous one at the accessible target point Drill head at the front end of the boring bar replaced by one Retractable head on which the pipeline, usually a somewhat flexible, endless one Plastic pipe that is attached. By pulling the boring bar back through the The borehole to the derrick or to the drill carriage is the pipeline in the Drilled hole.

The expansion head has the task of retracting and retracting on the one hand, to widen the borehole radially slightly again, and especially the surrounding walls of the borehole so far fasten that falling stones etc. do not pull the pipe in hindered or the pipe sliding past the stone is not damaged.

Furthermore, the pipeline should be as small as possible during the pulling-in exposed to additional loads.

Furthermore, the drill string should be made when drilling the hole despite simple and trouble-free operation easily and precisely with regard to the drilling direction be controllable, and fast and reliable drilling progress guarantee.

III. Presentation of the invention a) Technical task

It is therefore an object of the invention to provide a drill pipe which is particularly useful when used in horizontal drilling machines trouble-free and quick drilling of the hole as well as a reliable one Ensure the pipeline is pulled in without damaging the pipeline.

b) solving the problem

This task is in a generic drill pipe, which in the Usually in addition to the multi-part boring bar from the drill head that can be attached to it, the expanding head that can be used instead and a clamping jaw for gripping and pushing forward or backward of the boring bar through which characterizing features of claim 1 solved. Beneficial Embodiments result from the subclaims.

The main thing when pulling in the pipes is that Pipeline other than that due to the pulling in and friction on the Bore walls occurring loads as few additional as possible Suspend loads.

The boring bar carrying the expanding head, which consists of a large number of parts is composed, piece for during the withdrawal of the drill pipe Piece dismantled at the starting point of the drilling. Because the individual parts the boring bar usually with each other in the longitudinal direction are screwed, this means one when loosening this screw Longitudinal offset of the drill pipe by the length of this thread.

So when loosening the screw connections between the individual parts of the The drill pipe does not always retract or partially retract Pipe is compressed by this longitudinal displacement is at the Connection point between the boring bar and the feed head a non-rotatable, however axially movable length compensation is provided for this. This Length compensation is in particular in the normal position by means of a spring, ie at screwed thread between the individual parts of the boring bar, biased. This length compensation is particularly advantageously one Sliding nut, which is screwed into the front part of the drill pipe. This sliding nut has a non-circular, e.g. B. square or hexagonal, Outer circumference, and is in a corresponding inner circumference of the feed head slidably mounted. In addition, this feed head is on the front with one Cover closed, through which the front end of the drill pipe into the Opening and thus protrudes toward the sliding nut, with the lid on the circumference seals against the outer circumference of the drill pipe to prevent the penetration of Dirt to the sliding nut and its spring avoid.

At the other end of the sliding head, the pipeline or the extension part clamping the pipe, consisting of two together interacting conical ring surfaces connected to the feed head.

Since it often happens when pulling back the drill pipe that No further drill pipe with the force available can be moved backwards due to soil or stones that are moving jam between the drill pipe and the walls of the hole in these cases then attempts to retract the drill string further effect by using the drill string in addition to or instead of the retraction movement is rotated. Would such a rotation on the attached to the drill pipe Pipeline would be passed, this would be - especially with a first short drawn piece of the pipeline - to an undesirable Conduct torsional load on the pipeline. For this reason, the pipeline axially fixed, but rotatably attached to the feed head by the extension part the pipe is attached to a rotating part, which is in the feed head is rotatably mounted. The rotating part has a radial for this purpose projecting head on, which is free in a front opening of the feed head is rotatably mounted, and is held in the axial direction by the opening is in turn closed by a front cover, the through opening corresponds to the diameter of the shaft of the turned part and is therefore smaller than the outer diameter of the radially protruding head of the rotating part.

In this case too, this front cover is opposite the penetrating shaft of the rotating part sealed by a seal to prevent the penetration of Contamination in the interior of the feed head and that stored there Avoid turned part.

To the frontal frictional forces when the rotation between the rotating part is successful and to reduce the feed head are on both sides of the end faces of the radially projecting head of the rotating part from sliding disks or sliding rings a low-friction material, such as a plastic, especially made of Teflon, between the turned part and the adjacent surfaces of the feed head arranged. Otherwise, the turned part has as little axial play as possible towards the feed head so as not to remove each one Part of the boring bar reinserting a train after the Axial play suddenly occurring tensile load on the pipe occur to let, but this tensile load with increasing traction from the derrick from slowly rising in the pipeline.

The functions of length compensation and rotatability described above between the boring bar and the pipe to be pulled in, mediated by the Feed head, can also at the other ends of the front Be arranged feed head, and in particular also be functionally combined.

Furthermore, the feed head - in addition to the expanding and the Bore wall compressing bevel, which at the beginning of the feed head is arranged in the retraction direction - at least in one longitudinal region non-circular, preferably with opposite parallel surfaces, for example, square or hexagonal outer circumference, which is used to apply a shoe brake. This shoe brake is necessary in order to completely retract the pipeline and thus a Drill rig arrived feed head via screws between feed head and loosen boring bar. This is achieved by means of the shoe brake Retraction head held in a certain rotational position, and that in the feed head the front part of the boring bar screwed tightly broken loose.

In order to recognize the arrival of the feed head at the drilling rig, this indicates foremost part of the boring bar has an end position groove. This about the scope circumferential, annular groove is by a sensor attached to the drilling rig recognized by the surface of the drill pipe to the sensor in the area of the groove takes a different distance than in the not lowered by the groove Circumferential areas.

Because the end position groove has a different depth and / or a different axial extension has as the rest, each in the same position in each part of the boring bar existing position grooves, the arrival of the Feed head can be recognized, which otherwise when drilling the hole recognizes that the last assembled part of the boring bar is in its foremost position reached and be supplemented by a subsequent part of the drill pipe got to.

It has proven useful to use the position grooves and others also the end position groove with a material, in particular a plastic or Resin, to which the sensing sensor does not respond in order to to achieve a smooth outer contour of the drill pipe, and the settling to avoid contamination in the position grooves.

Because especially in small horizontal drilling machines, in which the Drilling begins from a vertical start shaft, in which a Drilling rig is lowered so that the direction of drilling is actually too When the drilling begins horizontally, the boring bar consists of relatively short ones Parts of about 15-40 cm in length. These parts have a tapered end thread screwed together.

Even with such small horizontal boring machines that are vertical Starting shaft, the direction of the drilling should be controlled can, and for this purpose also changed during the ongoing drilling can be.

In contrast to large horizontal drilling machines, which are inclined against one another working out the bottom surface of the gun carriage, and drilling with Support by high pressure water, which constantly rinses the borehole, Bringing forward is the so-called small horizontal drilling machines Drill pipe only by hydraulic forward pressing in Drilled direction advanced.

The directional control of the drill head is done by the fact that the Drill head at its front end is asymmetrical, extending across the longitudinal center of the drill head extending bevel, so that the angular position the slope that can be controlled by rotating the drill pipe with further pushing forward the lateral deflection of the drill head into the desired direction.

To do this on the multitude of between the parts of the drill pipe existing threaded screw connections, which in total are never completely free of play, not to be exposed to excessive transverse loads, it has especially from Proved advantage, this slope only at an angle of 20-30 ° to the vertical and only run slightly over the longitudinal center of the drill head As a result - viewed in the axial direction - the front of the Drilling head only formed by about ¾ of this control slope of the drilling head, while the remaining 20-25% as transverse to the longitudinal axis of the drill head standing end face remain, and also not as a counter slope etc. be formed. This increases the resistance when pushing forward of the drill head, but significantly improves the controllability of the drill pipe. A further improvement results from the fact that the foremost part of the Drill head has a cylindrical outer contour in which the Control slope, and in particular only in this cylindrical part. A conical widening part of the Drilling head into which the control slope no longer extends, which makes the deflection angle of the direction control better constant can be held.

In addition, the drill pipe must be inserted and withdrawn be ensured that the clamping jaw moving the boring bar can reliably pull or push the drill pipe without slippage. The Transmission of the forces in the axial direction on the drill pipe is on most reliable by positive locking, e.g. B. Gripping the drill pipe in the respective ring grooves, etc., but there is a risk of Hooking of the drill pipe in the borehole, on stones etc. For this reason preferably grips the clamping jaw only by means of frictional engagement Outer circumference of the individual parts of the boring bar.

As the outer circumference of the Boring bar is dirty, will be special according to the invention Precautions on the jaw that span several, e.g. B. three segments, extends around the outer circumference of the boring bar:

The three segments are loosely connected to each other by in the opposite directed contact surfaces recesses are housed, in which the two halves of the gap between two adjacent segments protrude bridging springs.

Above all, the penetration of dirt into the recesses in the springs must be avoided are also radially within these recesses for the springs are each arranged at least one slot in the contact surfaces, so that a plate with its two opposite ends in these slots can be used, thus also wiping the gap two adjacent segments covered, whereby the plate and thus the slots preferably extend over the entire axial length of the clamping jaws. The The plate is guided in the slots with as little or as little play as possible.

In addition, the inner circumference of the clamping jaw or its segments is not circular as the outer circumference of the boring bar, but demonstrates internal, viewed in the circumferential direction, only narrow, elevations, preferably only one elevation per segment, with which the clamping jaw rests on the outer circumference of the boring bar.

Because these bumps are less than 20% of the circumferential length of the boring bar is, with a constant, radially inward clamping force the surface pressure between the jaw and the usually massive and thus very resilient boring bar surface pressures greatly increased. This ensures a non-slip system, which is also ring-shaped, V-grooves in the elevations that run transversely to the direction of pull or push is further improved. Order also in the radial between the deporting (???) Plate and the inner circumference of the jaw remaining area of the gap the deposit of dirt between the segments of the clamping jaw prevent, which prevents the clamping jaw from tightening, is as close as possible starting at the slot for the plate - viewed in the axial direction - the Gap between the segments radially inward widening slope arranged. Through this bevel when pressing against each other individual segments and thus existing when clamping the clamping jaw Dirt is pressed radially inwards out of the gap, thereby preventing it also not the system of the clamping jaw on the outer circumference of the boring bar because the elevations formed on the inner circumference of the clamping jaw are not immediately next to the slope, but away from it, preferably in the middle of each segment.

Only by combining the above-mentioned further training courses with the individual parts of the drill pipe, i.e. on the drill head, feed head and Boring bar and jaw can be a reliably functioning Ensure drilling progress or pulling in of the pipeline. The Further training on the feed head through the specific properties of the means Small drilling rigs usually retracted plastic pipes, and on the other hand through the special used in these small drilling rigs Design of the boring bar, namely consisting of short, solid parts, which are screwed together using threads, especially in the form of a cone. There is also between this type of boring bar and the training of The interaction previously described in detail.

c) working examples

Fig. 1:

das Bohrgestänge mit Einzugskopf,

Fig. 2:

den Bohrkopf, und

Fig. 3:

die Spannbacke.

An embodiment according to the invention is described in more detail below with reference to the figures. Show it:

Fig. 1:

the drill pipe with feed head,

Fig. 2:

the drill head, and

Fig. 3:

the jaw.

Fig. 1 shows the feed head in longitudinal section. In the right end of the Retraction head 1 is screwed into the front end of the boring bar 20, and on left end of the feed head 1 is a suitable fastening part 46 that End of the pipe 22 attached. The fastening part usually consists of a pair of coaxial, conical sockets, the tapered bevel of each other are directed, and which take up the pipe wall between them. This Fastening part 46 is non-rotatably and axially fixed to a rotating part 5, for. B. by means of a fastening eyelet 6 extending transversely through the rotating part Rotating part 5 allows a relative rotation between the feed head 1 and Pipeline 22, by rotating part 5 on that facing away from the pipeline 22 End has an annular radially projecting head which in a corresponding front opening of the body 47 of the feed head 1 is rotatable, and by a screwed on the face of the body 47 Lid 9 is prevented from pulling out. The cover 9 is via a seal 8 sealed against the shaft 26 of the feed head 1. Between End faces of the radially projecting head 25 and the opposite End faces of feed head 1 or cover 9 are slide rings 7 made of one Plastic, e.g. B. Teflon, arranged to the sliding friction when turning between to keep the rotating part 5 and the body 47 as small as possible.

The receptacle for the rotating part 5 is connected in the axial direction, that is to say from the left 1 to the right, an area of reduced outer circumference of the Corpus 47 in which it is designed as a hexagon 3 for attaching one shoe brake, not shown.

At this hexagon 3 there is axially a shoulder with again reduced, round diameter on which a round plate 10 is placed and with the body 47 is welded.

On the end of this plate 10 facing away from the pipeline 22 is a Screwed socket 11, inside - supported against the body 47 by means of a compression spring 14 - a sliding nut 2 with a non-circular, especially hexagonal or quadrangular, outer circumference slidable, however is rotatably mounted relative to the socket 11 and thus the feed head 1.

The opening in the socket 11 in the right end face is smaller than the outer circumference of this sliding nut 2, but just big enough to do that to pass the front end of the foremost part 20a of the boring bar 20, and the end thread 19 applied there in the end region with the to screw the matching internal thread of the sliding nut 2. Seals here too a seal 13 arranged in a ring in the end opening 12 of the bushing 11 with respect to the circumference of the part 20a of the foremost part of the boring bar 20 from.

At the transition between the end face in which the end opening 12 is introduced, and the outer circumference of the bushing 11 is an expansion bevel 4 rotationally symmetrical and thus circumferentially attached when moving back of the feed head 1 through the borehole, in Fig. 1 from left to right, that Widen the borehole again and, above all, solidify the walls of the borehole should.

The outer circumference of the body 47 is preferably not larger than that Outer circumference of the bush 11 of the feed head 1.

The foremost part 20a of the boring bar 20 has at its right end Taper thread 17, like all other parts 20b, 20c, ... of the boring bar 20, by means of which the individual parts are screwed together. In The part 20a also has a defined axial distance to the taper thread 17 Position groove 16 on the same shape in all other parts 20b, 20c the boring bar 20 is present, and the detection of a particular one Axial position arranged by a stationary, for example on the derrick Serves sensor. To prevent dirt and deposits in the position groove 16 avoid using a plastic that does not react to the sensor, for example synthetic resin, poured out so that there is a smooth, cylindrical Outer surface of the parts 20b, 20c of the boring bar 20 results.

At the foremost part 20a of the boring bar connected to the feed head 1 20 an end groove 15 is also arranged, which is axial Extension and / or depth or other distinguishable features distinguishes and serves with the same sensor when retracting the Drill pipe to indicate the arrival of the feed head 1 on the sensor. Also this groove can be filled with synthetic resin 18 for the same reasons.

Figures 2 show a drill head, each viewed transversely to the longitudinal direction 50, but from viewing angles rotated by 90 °.

It can be seen that the drill head is essentially rotationally symmetrical is, with an end facing away from the front boring bar 20, not shown, arranged cylindrical part 30, and a subsequent truncated cone 31, in the course of which the diameter in the direction of the drill pipe one increases at an angle 32 of about 45-60 °. This truncated cone 32 closes there is at least again a short cylindrical area for solidifying the Wall of the borehole.

For the directional control of the bore described above is the first one cylindrical part 30 milled obliquely, so that a guide bevel 28 is formed, which is at an angle of 20-30 ° with respect to the longitudinal direction 50, and itself extends slightly beyond this central axis of the cylindrical part 30. The remaining end face part 48, which runs transversely to the longitudinal direction 50, is approximately 20-40% of the total cross section of the cylindrical part 30, which can have a diameter of 3-4 cm, for example.

The guide bevel 28 preferably extends over the entire Length of the cylindrical part 30, however, no longer extends into the truncated cone 31 inside.

Since this drill head is longer than the parts 20b, 20c, ... of the boring bar 20 proceeded when drilling the hole so that in the vertical Starting shaft of the drilling rig is only lowered after the drilling head has been placed inside the tower as the start of the drill pipe.

Likewise, after pulling back the drill pipe and pulling in the Pipeline 22 of the feed head 1 detached from the last part of the boring bar 20 before the drilling rig can be lifted out of the starting shaft.

Fig. 3 shows the clamping jaw 35, which for gripping the outer circumference of the Boring bar 20 and its pushing forward or backward serves, in Fig. 3a in a Cross-sectional view and in Fig. 3b in part in longitudinal section. Like in the 3a can be seen, the clamping jaw 35 consists of three segments 36a, 36b, 36c, each about 120 ° around the circumference of the Extend pipe 22, not shown, and between each keep a distance 37. Each of the distances extends at least one spring 39 away, which in the mutually directed Radial surfaces 45a, 45b of two adjacent segments 36a, 36b and 36b, 36c is introduced vertically. Because the springs 39 are relatively accurate in this Fit recesses 38a, 38b, there is a loose connection and tangential guidance of the individual segments to each other.

However, in order to prevent dirt from entering the distance 37, which the radial movement of the segments against each other and thus the tensioning of the Prevented jaw 35 is also located radially further inside, near the Inner circumference of the jaw 35, each a plate 41, which is preferably Extends the distance 37 over the entire length of the clamping jaw 35 overlapping, in corresponding slots 40a, 40b, which are in the Radial surfaces 45a, 45b are in alignment. This makes a radial Penetration of dirt that adheres to the pipe 22 to the outside in the distance 37 prevented. To also in the radially inside the plate 41 located area of the distance 37 to prevent pollution begins as radially as possible within the plate 41 on the radial surfaces 45a, 45b a bevel 43a, 43b which widens radially inwards, through which a dirt located there is pressed radially inward when the Clamping jaw 35 is clamped.

In order for the clamping jaw 35 to bear against the pipeline 22 with a high The clamping jaw, i.e. each of the segments, lies to enable surface pressure 36a, 36b, 36c not with their entire inner circumference on the pipeline 22, but only with a part of the inner circumference, which is why in the middle of each An elevation 42 is formed in the segment running in the axial direction approx. 16 ° of the segment angle of 120 °, i.e. not even 10% of the circumferential area, is. Only with these surveys 42 are the segments on the The outer circumference of the pipeline 22 and the grip on the pipeline is additionally improved by the fact that 42 are annular in these elevations are circumferential, V-shaped circumferential grooves 44, which are shown in Fig. 3b.

REFERENCE SIGN LIST

1

Feed head

2nd

Sliding nut

3rd

Hexagon

4th

Expansion slope

5

Turned part

6

Fastening eyelet

7

Slide rings

8th

poetry

9

cover

10th

plate

11

Rifle

12th

Forehead opening

13

poetry

14

feather

15

Final groove

16

Position groove

17th

Taper thread

18th

Synthetic resin

19th

End thread

20th

Boring bar

21

Drill head

22

Pipeline

23

Borehole

24th

cavity

25th

head

26

shaft

27

cavity

28

Leading slope

29

Beginning

30th

cylindrical part

31

Truncated cone

32

Cone angle

33

Axis direction

34

angle

35

Jaw

36a, 36b, 36c

Segments

37

distance

38a, 38b

Recess

39

feather

40a, 40b

slot

41

plate

42

Survey

43a, 43b

Weird

44

Circumferential groove

45a, 45b

Radial surface

46

Fastener

47

Body

48

Frontal part

50

Longitudinal direction

Claims (15)

Drill rods, especially for horizontal drilling machines, with a multi-part boring bar (20), a drill head (21), and a feed head (1) for pulling a pipeline (22) into the borehole (23), a clamping jaw (35) for holding and pushing the boring bar (20) forward or backward,
characterized in that on the feed head (1) at one end a rotating part (5) for fastening the pipeline (22) to be drawn in is rotatably, axially fixed, and at the other end of the feed head (1) the end of the boring bar (20) is axially displaceable, rotatably arranged. A drill pipe according to claim 1,
characterized in that
the feed head (1) has on its outer circumference a non-circular, in particular hexagon (3), engagement surface for a shoe-type brake, which is lowered relative to the outer circumference of the feed head (1), in particular in the form of a groove. Drill pipe according to one of the preceding claims,
characterized in that
the displaceable, non-rotatable arrangement of the front end of the boring bar (20) in the feed head (1) takes place by means of an out-of-round sliding nut (2), in particular square on the outer circumference, into which the boring bar (20) with the front end by means of an end thread (19) can be screwed in. Drill pipe according to one of the preceding claims,
characterized in that
the sliding nut is displaceable in a cavity (27) of the feed head (1) and is biased in the direction of the boring bar (20) by the force of a spring (14). Drill pipe according to one of the preceding claims,
characterized in that
each of the interconnected segments (20a, 20b, 20c, ...) of the boring bar (20) has a preferably circumferential position groove (16) in the outer circumference for scanning by means of a sensor, which is made of a material that is not responsive to the sensor, in particular synthetic resin, is filled out. Drill pipe according to one of the preceding claims,
characterized in that
the drill head (21) has at its front end a bevel (28), viewed in the axial direction, which extends over the central axis of the drill head (21). Drill pipe according to one of the preceding claims,
characterized in that
the drill head (21) has no opposite slope, and in particular the end region between the beginning (30) of the slope and the outer circumference of the drill head tip is approximately 20% of the end face of the drill head tip and extends transversely to the longitudinal axis of the drill head (21). Drill pipe according to one of the preceding claims,
characterized in that
the bevel (28) extends over the entire length of the cylindrical part (30), which represents the front end of the drill head (21), and a frustoconical part (31) adjoins the cylindrical part. Drill pipe according to one of the preceding claims,
characterized in that
the cone angle (32) of the truncated cone (31) with respect to the axial direction (33) is 40-60 °, in particular 45-55 °. Drill pipe according to one of the preceding claims,
characterized in that
the clamping jaw (35) consisting of a plurality of segments (36a, 36b, 36c) which result in the complete circumference in the radial surfaces (45a, 45b) which are directed towards one another in two adjacent segments and which are arranged in the vicinity of the inner circumference and perpendicularly into the radial surfaces (45a, 45b) have immersing slots (40a, 40b), into each of which plates (41) are inserted, which overlap the distance (37) between two adjacent segments and extend essentially over the entire axial length of the clamping jaw (35). A drill pipe according to claim 10,
characterized in that
radially outside the plates (41), the springs (39) bridging the distance (37) are also arranged in recesses (38a, 38b) which plunge vertically into the radial surfaces (45a, 45b) for holding together the adjacent segments (36a, 36b) or (36b, 36c). Drill pipe according to one of the preceding claims,
characterized in that
the inner circumference of the segments (36a, 36b, 36c) of the clamping jaw (35) has at least one elevation (42) running in the axial direction for contact with the circular outer contour of the boring bar (20), the proportion of which on the inner circumference of the clamping jaw (35) is less than 35 %, in particular less than 20%. A drill pipe according to claim 12,
characterized in that
have in the elevations (42) circumferential grooves (44) with in particular V-shaped cross-section and a V-angle of 50-70 °, in particular of about 60 °. Drill pipe according to claim 11 to 13,
characterized in that
the radial surfaces (45a, 45b) merge at their radially inner end into a slope (43a, 43b) to the inner circumference of the respective segment (36a, 36b, 36c). A drill pipe according to claim 14,
characterized in that
the bevels (43a, 43b) have an angle of 40-50 ° with respect to the radial direction, and extend essentially over the entire axial length of the clamping jaw (35).

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