EP2085566B1 - Drilling assembly - Google Patents

Description

The invention relates to a drilling rig comprising a drill ramp, a displaceably arranged on this drive unit with a boom receptacle for releasable connection to a drill pipe and with a drive motor, which communicates with the boom receiving in torque-transmitting connection, and a rod for receiving coaxial feed pipe receptacle for releasable connection with a Casing, wherein additional coupling means (46, 74) are provided for torque transmitting connection between the drive motor (24) and the casing receiving means (32) and wherein the casing receiving means (32) has a cylindrical pipe section (48) attached to the drive unit (18) thereof. far end with a liner (60) is connectable.

A drilling rig of the aforementioned type is for example from the EP 383 225 A1 or the DE 20 26 364 A1 known.

Furthermore, large rigs are known, which usually have a double drive head, in which the drill string and the casing pipes are driven separately via their own hydraulic motor and thus driven simultaneously into the ground. This requires an expensive drive head and expensive drive hydraulics.

In small rigs, it is also known to advance alternately first the casings and then connected to the drill string drilling head. This is cumbersome and time-consuming, since the recording of the drive head must be changed in each case when changing between liner pipes and pipe string. Often it is not possible to advance the casings at once to the required depth, as the ground does not allow this. Then the liner pipes have to be driven for example a few meters. Then the drill head drills this distance, then again the casing pipes are driven by a unit distance and so on.

In the solution mentioned above, the drill pipe and the casing are driven in rotation by the same drive motor and can thus be driven simultaneously into the soil. Such a drilling rig is smaller, lighter and cheaper than the above-described large drilling rigs. It can be used in construction sites that are inaccessible to large scale facilities and can more economically drill holes such as geothermal wells at depths of 70 to 140 meters. Since the drive head has only a single hydraulic motor, the drive hydraulics required for this purpose is relatively simple in construction.

The invention has for its object to avoid the uncontrolled leakage of drilling mud at the upper end of the casing.

This object is achieved in that the cylindrical pipe section is closed at its end facing the drive unit by a lid which has a passage opening for the boom receptacle, wherein the cylindrical pipe section near its drive end has at least one outlet opening for a drilling fluid and of a this covering discharge ring is surrounded, which is freely rotatable relative to the pipe section and sealed on both sides of the outlet opening and which has a connectable to a drain pipe for the drilling fluid radial outflow channel.

Thus, the ascending in the annular gap between the drill pipe and the casing pipes drilling mud can be removed to the side and transported into a sludge well, without the actual construction site completely dirty. The drilling mud, which is fed, for example, by compressed air, which is fed to a downhole hammer connected to the drill string, would otherwise be blown out of the casing at high speed and pollute the adjacent building facades and the entire construction site area. In order to reliably prevent the escape of drilling mud at the construction site, it is expedient if the passage opening on the cover can be sealed off from the boom support by adjustable seals and also the seals between the bearing race and the cylindrical pipe section can be adjusted. The above-described derivation of the drilling mud is also applicable with advantage, when boom support and feed tube receiving are each driven by their own drive units. Preferably, the coupling means are designed for the transmission of a torque in both directions of rotation, so that the screw connections between the individual casing pipes and the individual drill pipe sections can also be produced and released with the aid of the drive motor.

The boom support and the Futterrohraufnahme can be firmly connected. In a preferred embodiment, however, the coupling means comprise a driver disposed on the boom receptacle and a rotational stop on the liner receiving means for engaging the rod receptacle such that a rotationally fixed connection between the boom receptacle and the liner receiving means can be made without rigidly connecting the two members together , The driver and the rotation stop, for example, be designed in the manner of a bayonet closure, the bayonet lock on the two rotation stops a Zugverrastung or a pull and Schubverrastung can have. This is not only a rotationally fixed connection, but also a load on shear and tensile loads between the linkage support and the feed pipe receiving is given.

The feed pipe receiving associated parts of the coupling means are suitably arranged on the lid of the feed tube receiving. The outlet for the drilling mud may consist of several distributed over the circumference of the cylindrical pipe section and separated by webs slits. The slots can be over a substantial part of the circumference of the cylindrical pipe section extend. The remaining webs need only be so wide that they ensure a torque transfer from the cover to the cylindrical pipe section. For example, the slots may extend together over about 340 ° of the tube circumference.

As already mentioned above, the drill string can be connected to a fluid-operated down-the-hole hammer, wherein the pressure medium can be fed through the hollow drill pipe. Normally, the Imlochhamer carries a drill head whose outer diameter is smaller than the inner diameter of a casing. This allows the downhole hammer to be pulled up inside the casing. However, with a normal drill bit, the casings can only be propelled through loose soil and through loose rock until the casings meet the first layer of rock. From then on the hammer must continue drilling alone. This is also sufficient in most types of subsoil, as the subsoil tends to remain rocky with increasing depth once the rock has started. The Imlochhammer can drill in Felsgut alone without casings, because rock is usually stable. The drilling becomes problematic only when in one certain depth of rock is coming, below this layer of rock but again loose rock follows, so that the drilling channel can coincide. Then the casings have to be drilled through the layer of rock. For this purpose, the down-the-hole hammer can carry an eccentric boring head whose smaller outer diameter is smaller than the inner diameter of a casing and whose largest outer diameter is greater than the outer diameter of a casing. Thus, the Imlochhammer can be opened and lowered through the casings. Once the drill head is below (outside) the casing, the downhole hammer is rotated in the direction of work. As a result, the two halves of the Exzenterbohrkopfes move against each other outwards, so that the bore diameter is now greater than the outer diameter of the casing pipes. The down hole hammer can thus drill boreholes through rock strata which are larger than the casings, so that the casings can also be laid through the rock strata. As a result, casings can also stabilize wells in loosened rock that lies below rock strata.

In order to stabilize the radial position of the Imlochhammers relative to the respective lowest casing, it is useful if a transition piece is arranged between the drill string and the Imlochhammer, which is provided with radial Zentrierstegen. The axial length of the transition piece is expediently chosen so that the drill head protrudes from the mounted first casing on the pipe fitting mounted on the drill pipe or the drill pipe.

The drill ramp can in a conventional manner in different working positions between a horizontal and a vertical end position are adjustable so that can be drilled horizontally or vertically or in any intermediate position. Furthermore, in each case a clamping device for the drill string and the casing can be arranged in a conventional manner on the drill ramp. The clamping devices expediently assigned to the drilling ramp breakaway device so as to solve the tightened by working screw between the linkage sections and the liner pipes can.

Fig. 1

eine teilweise schematische perspektivische Gesamtansicht der erfindungsgemäßen Bohranlage,

Fig.2

eine perspektivische Darstellung der Gestängeaufnahme und der mit dieser koppelbaren Futterrohraufnahme,

Fig. 3

eine Darstellung der Gestängeaufnahme und der Futter- rohraufnahme, letztere in einem die Achse enthaltenden Schnitt,

Fig.4

eine perspektivische, teilweise geschnittene Darstellung der Gestängeaufnahme und der Futterrohraufnahme im gekop- pelten Zustand,

Fig. 5 und 6

abgewandelte Ausführungsformen der Bajonettverschluss- elemente an der Futterrohraufnahme und

Fig. 7 und 8

jeweils eine Schnittansicht durch ein Futterrohr mit einem Imlochhammer zur Erläuterung der Montage desselben an dem Bohrgestänge.

Further features and advantages of the invention will become apparent from the following description, which explains the invention with reference to an embodiment in conjunction with the accompanying drawings. Show it:

Fig. 1

a partially schematic perspective overall view of the drilling rig according to the invention,

Fig.2

a perspective view of the boom receiving and coupled with this feed pipe receiving,

Fig. 3

an illustration of the boom support and the feed tube holder, the latter in a section containing the axle,

Figure 4

a perspective, partially sectioned representation of the boom support and the Futterrohraufnahme in the coupled state,

FIGS. 5 and 6

modified embodiments of the bayonet closure elements on the feed tube receiving and

FIGS. 7 and 8

in each case a sectional view through a casing with an in-hole hammer to explain the mounting of the same on the drill string.

The in the FIG. 1 illustrated drilling rig according to the invention comprises a chassis 10 with a chassis 12 to which a drill ramp 14 is pivotally articulated so that it by means of a working cylinder 16 between in the FIG. 1 shown vertical position and an approximately horizontal position is adjustable, in which it rests on the chassis 12.

At the drill ramp 14, a generally designated 18 drive unit for the drill pipe and the casing pipes is arranged. It comprises a carriage 20 which is guided displaceably on the drill ramp 14 in the direction of the double arrow A and can be moved by a carriage drive 22 via a drive chain (not shown). On the carriage 20, a hydraulic motor 24 is arranged, which drives a spindle 26. With this a rod receptacle 28 can be coupled, which is connectable to a drill pipe, not shown, via a screw 30. With the rod receptacle 28, in turn, a feed tube receptacle 32 can be coupled, as will be explained below. In the lower part of the drill ramp 14 a casing clamp 34, a drill pipe clamp 36 and a breakaway device 38 are arranged on this, which are known per se and need not be explained in more detail. In the clamping devices 34 and 36 are the casings or drill pipe hydraulically clamped. In cooperation with the clamping devices, the breakaway device 38 enables the loosening of the screw connections between the individual casing pipes or drill pipe sections.

An operating unit 42 for operating the drilling rig is arranged on an arm 40 connected to the chassis 12.

In the Figures 2 and 3 one recognizes first again the rod-shaped boom receptacle 28, which can be firmly connected at its upper end via a flange 44 in a manner not shown with the spindle 26 of the drive unit 18. It can be screwed at its lower end over the conical threaded pin 30 with a drill pipe section. Near the upper end of the boom support 28 carries radially directed pin-shaped driver 46th

The arranged below the boom receptacle 28 feed tube receptacle 32 consists of a cylindrical pipe section 48 which is closed at its upper end by a cover 50. The lid has a passage opening 52 through which the rod-shaped boom receptacle 28 coaxial with the pipe section 48 can be inserted into this. This opening is sealed relative to the rod holder 28 by adjustable seals 54. At its lower end, the cylindrical pipe section 48 is provided with an internal thread 56 which is adapted to be screwed to a corresponding external thread section 58 of a casing 60 (FIG. FIGS. 5 and 6 ) serves.

Near the lid 50 48 outlet openings 62 are formed in the pipe section, which are separated by webs 64 (of which in the FIG. 2 only one can be seen). The outlet openings 62 are covered by an outlet ring 66 surrounding the pipe section 48, which has an outlet channel 70 connected to a connection pipe 68 for a drainage pipe. The discharge ring 66 is freely rotatable relative to the pipe section 48 and sealed by adjustable seals 72 above and below the outlet openings 62. The outlet openings 62 and the outlet channel 70 serve for the discharge of drilling mud, which is expelled upwards between the drill pipe and the casing pipes.

On the top of the lid 50 four angular stops 74 are arranged, which are intended to cooperate with the drivers 46 on the boom receptacle 28 in the manner of a bayonet closure. In the illustration in FIG. 2 the Mitnehmbolzen 46 can pass through the gap between the two stop members 74. After inserting the boom receptacle 28 into the feed tube receptacle 32 and rotating the rod receptacle 28 relative to the feed tube receptacle 32, a rotationally fixed connection between the rod receptacle 28 and the feed tube receptacle 32 can be produced in this manner (FIG. Figure 4 ).

The FIGS. 5 and 6 show two variants of this compound, which when exercising a train ( Figure 5 ) or train or thrust ( Figure 6 ) on the boom receiving a locking of the driver with the arranged on the lid 50 of the feed tube receiving stop elements 74 ensure 74. This can reliably prevent inadvertent release of the connection during operation. The bayonet lock between The boom support 28 and the liner receiving means 32 ensures that boom support and liner receive rotation in both directions simultaneously and that full torque can be transferred. On the other hand, the bayonet closure allows a rapid release of the feed tube receiving the boom recording.

Based on FIGS. 7 and 8 Now, the assembly of the casing pipes and drill pipe and the operation of the drilling rig will be described.

It is believed that the sinking of the wellbore is accomplished by means of a downhole hammer 76 which carries a drill head 78 at its lower end. Above the idler hammer a transition piece 80 is mounted, which carries three Zentrierstreben 82, which serve for centering the Imlochhammers 76 within the first casing 60. This carries at its lower end a casing crown 84. The length of the transition piece 80 is selected so that the drill head 78 by the flow distance a before (below) the casing crown 84 is located as soon as the first casing 60 and the hole hammer 76 with transition piece to the drive unit 18 of the drilling rig are mounted.

In order to mount the Imlochhammer and the first casing, the casing crown 84 are screwed to the first casing 60 and the Imlochhammer 76 with the transition piece 80. The first casing 60 has in its lower portion two diametrically aligned bores 86 through which a mounting bolt 88 (FIG. FIG. 8 ) is plugged. If the down-hole hammer is pushed into the first casing and this is positioned vertically, the transition piece 80 now looks as far up out of the first casing, that it with the boom recording 28 can be screwed. The mounting bolt 88 is positioned so that the drill head 78 is reset by the distance b from its working position. If the mounting bolt 88 is removed, the drive unit 18 is moved down to the drill ramp down so far that the feed tube holder 32 can be screwed to the first casing.

Now the Imlochhammer is turned on (compressed air supplied) and casing and in-hole hammer are pressed simultaneously rotating (at about 30 revolutions per minute) into the ground, until the first casing is almost retracted over its entire length. The excavated soil is carried by the emerging compressed air upwards and discharged laterally controlled by the outlet opening 62 and the outlet channel 70. The casing is placed so far into the soil until it can just be detected by the casing clamp 34. The downhole hammer is stopped and unscrewed the Futterrohraufnahme. Subsequently, the drive unit 18 is driven by a return stroke upwards, which is set so tight that now the transition piece 80 clamped by the linkage clamp 36 and the rod seat 28 can be unscrewed.

All clamping and screwing operations are hydraulically, i. not manually. The two clamps are controlled to hold the liners and linkage reliably until the operator reopens the clamps.

Subsequently, the next pair of drill pipe / casing is mounted. Both have the same effective length, for example 1.5 meters. The threads on the linkage sections and casing pipes have the same direction of rotation, so they are designed either as right-hand or left-hand thread. The linkage section is pushed into the casing. Both are placed vertically and lifted into the drilling rig. Due to the return stroke b, the drill pipe can now first be screwed to the transition piece 80 and the boom support. Subsequently, the linkage clamp is released and the drive unit 18 lowered so far that the casing can be screwed to the already introduced casing and with the feed tube recording. Thereafter, the drill head 78 is again to the flow a in front of the casing crown. The Imlochhammer is turned on and introduced the next length of casing.

The process described above is repeated until the casings meet rock. Subsequently, the Imlochhammer can drill with the drill pipe alone further, as in the rock, a well stabilization through casings is no longer required. All you have to do is loosen the bayonet lock between the boom support of the feed tube holder. The driving pin 46 on the rod holder 28 is rotated in the middle position of the bayonet lock and extended upward. The casing liner 32 remains on the last casing and continues to serve to drain the mud while mounting additional pipe sections until the final well depth is achieved.

If loose rock is encountered again below the rock layer, the loose rock layer must be stabilized with casings. For this, the casings must be routed through the layer of rock. The Imlochhammer is pulled out completely. The drill head is replaced by an eccentric drill head. This consists in a conventional manner of two halves, which fit in normal position through the casings. As soon as the eccentric drilling head is located in its drilling position below the lowermost casing and is rotated in the working direction, the two eccentric halves shift outwards relative to one another. As a result, the bore diameter is larger than the outer diameter of the casing pipes. Thus, the borehole for the introduction of the casing pipes can be extended accordingly.

Once the final drill hole depth has been reached, the drill pipe is pulled up completely with the downhole hammer and disassembled. In the well, the geothermal probe for geothermal energy or the well pipe or other desired carrier pipe or the like is drained. Then the casings are pulled upwards and dismantled. When disassembling the drill pipes or casings help the clamping and breakaway devices 34, 36, 38 of the drilling rig. They solve the respective threaded connections by the linkage clamp 36 the penultimate linkage section or the liner clamp 34 clamps the penultimate casing and the breakaway device 38 clamps the last linkage section and the last casing and rotates. Once the threaded connection is released, the drive unit 18, the corresponding pipes or pipe sections completely unscrew.

Claims (15)

1. A drilling assembly, comprising a drilling ramp (14), a drive unit (18) mounted on said drilling ramp in a slideable manner and provided with a rod receptacle (28) for releasable connection with drill rods and having a drive motor (24) in a torque-transmitting connection with the rod receptacle (28), as well as a casing pipe receptacle (32) arranged coaxially with the rod receptacle (28) for releasable connection with a casing pipe (60), wherein additional coupling means (46, 74) are provided for a torque-transmitting connection between the drive motor (24) and the casing pipe receptacle (32) and wherein the casing pipe receptacle (32) has a cylindrical pipe portion (48) which is connectable to a casing pipe (60) at its end distal to the drive unit (18), characterized in that the end of the cylindrical pipe portion (48) directed towards the drive unit (18) is closed by means of a cap (50) having through opening (52) for the rod receptacle (28), and in that the cylindrical rod section (48) is provided with at least one outlet opening (62) for a drilling liquid near its end located at the drive side and is surrounded by an outlet ring (66) covering said outlet opening, which outlet ring is freely rotatable with regard to the rod section (48), sealed to both sides of the outlet opening (62) and has a radial discharge canal (70) connectable to a discharge pipe for the drilling fluid.
2. The drilling assembly according to Claim 1, characterized in that the coupling means comprise an actuator (46) mounted on the rod receptacle (32) as well as a rotary stop (74) on the casing pipe receptacle (32) provided to come into engagement with said actuator.
3. The drilling assembly according to Claim 2, characterized in that the coupling means are formed in the manner of a bayonet coupling.
4. The drilling assembly according to Claim 3, characterized in that the bayonet coupling is provided with a draw latch arrangement on both stops.
5. The drilling assembly according to Claim 4, characterized in that the bayonet coupling is provided with a push-pull latch arrangement on both stops.
6. The drilling assembly according to one of Claims 1 to 5, characterized in that the components (74) of the coupling means assigned to the casing pipe receptacle (32) are arranged on the cap (50).
7. The drilling assembly according to one of Claims 1 to 6, characterized in that the through opening (52) in the cap (50) is sealable versus the rod receptacle (28) by means of re-adjustable seals.
8. The drilling assembly according to one of Claims 1 to 7, characterized in that the seals (72) between the outlet ring (66) and the cylindrical pipe section (48) are re-adjustable.
9. The drilling assembly according to one of Claims 1 to 8, characterized in that the outlet opening (62) consists of a plurality of slits arranged along the circumference of the cylindrical pipe section (48) and separated from each other by means of bars (64).
10. The drilling assembly according to one of Claims 1 to 9, characterized in that the drill rods are connected to a pressure-fluid-operated down-the-hole hammer (76), wherein the pressure fluid can be supplied via the hollow drill rods.
11. The drilling assembly according to Claim 10, characterized in that the down-the-hole hammer (76) carries a drilling head (78) whose external diameter is smaller than the internal diameter of the casing pipe (60).
12. The drilling assembly according to Claim 10, characterized in that the down-the-hole hammer (76) carries an eccentric drilling head whose smallest external diameter is smaller than the internal diameter of a casing pipe (60) and whose biggest external diameter is bigger than the external diameter of a casing pipe (60).
13. The drilling assembly according to one of Claims 10 to 12, characterized in that between the drill rods and the down-the-hole hammer (76) a transition element (80) is arranged which is provided with radial centering fins (82).
14. The drilling assembly according to Claim 13, characterized in that the axial length of the transition element (80) is selected such that the drilling head (78) on the down-the-hole hammer (76) mounted on the rod receptacle (28) projects out of the mounted first casing pipe (60).
15. The drilling assembly according to one of Claims 1 to 14, characterized in that respective clamping devices (34, 36) for the casing pipe (60) and for the drill rod are arranged on the drilling ramp (14) and in that a break-apart device (38) mounted on the drilling ramp (14) is assigned to the clamping devices (34, 36).

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