DE2309570A1 - DRILL RIG AND DRILL STRING INSERT ARRANGEMENT - Google Patents

Description

Bremen, February 22, 1973 Sch / B.

Application for patent and utility model my file number: 73.26 Demarok / F /

APPLICANT:

Demarok International Limited,

East Winch Hall, East Winch, Near Kings Lynn,

Norfolk, England

INVENTOR:

Richard Nicholas-Bray

Farthings, Restwell Avenue, Cranleigh, Surrey,

England

REPRESENTATIVES according to § 16 PatG:

Dipl.-Ing. Martin Schumacher, patent attorney, 28 Bremen 1, Ellhornstr.

NAME: Drill rig and drill string insert assembly

Generic term:

The invention relates to a drilling device with jointly propellable inner and outer drill string and Means for rotary percussion driving the drill string insert assembly.

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State of the art

In the known drilling devices of this type, the both drill strings coupled to one another for a common rotary percussion movement. A boring bar insert is with a Rotary impact drive source connected, being at the lower end of the insert a threaded hole is provided into which the inner strand is screwed. The lower part of the Inner insert is externally threaded and a sleeve-shaped The upper end of the hollow insert is screwed onto the lower part of the inner insert. The lower part of the hollow insert extends below the inner insert and is internally threaded to the top piece of the Include outer strand. The two drill strings are thus rigidly coupled to one another for simultaneous transmission the rotation and flapping movement.

Above the hollow insert is a flushing head on the inner insert set, whereby the flushing head is rotatably connected to the inner insert so that the flushing head can remain at rest, while the indoor insert rotates. Through the flushing head, a flushing agent is in the space between the inner and outer strand brought and the inner insert is provided for this purpose with Axialkanä-len, which extend from the flushing head to extend to the reason of the mission. The inner liner also has an axial one extending over its entire length Channel through which detergent can get to a central channel that extends over the entire length of the inner strand

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extends to an outflow of detergent at the inner Drill bit or To achieve drill bit.

When drilling through rock covered by overburden, consisting of earth or other loose material Material, the inner and outer drill string become through the earth material and also a short distance into the rock driven forward together. Then the inner strand alone is driven through the rock, while the outer strand remains dormant and serves as a protective tube to protect the inner strand against pressure from the ground. In the known construction of the drill, the two inserts must first be uncoupled and the inner insert must be raised verden in order to connect further inner strand pieces can. In order to uncouple the two inserts, however, a screw movement must be made, which is time consuming. In addition, the mounting of the flushing head is subject to high wear, because the flushing head is directly on the inner insert is attached to its rotary percussion drive. Another disadvantage is that the indoor use is relatively is expensive because it has to be provided with three instead of a single channel as usual and because the arrangement of channels near the outside of the inner insert leads to undesirable cross-sectional weakening.

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task

The invention is based on the object of providing a drilling device and a drill string insert arrangement of the type indicated at the outset To create kind that allows easy and time-saving handling when extending the inner drill string and is characterized by a simple, solid construction.

Solution of the task

According to the invention, the stated object has been achieved in that the drill string insert assembly consists of a first, inner insert connectable to the inner drill string and a second, outer insert connectable to the outer Drill string is connectable, there is, wherein the outer insert slidably but non-rotatably the inner insert in a bore records.

In order to enable the two inserts to rotate together, the inner insert with a sliding seat can be stored in the outer insert be, the engagements of the two inserts have a non-wedge-shaped cross-section.

The arrangement described, in which the two inserts are not firmly connected to each other, allow the Lift the inside insert without having to make screw movements of the couplings.

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Since, according to the invention, the two inserts are not rigid with one another are connected * it is necessary to provide funds to transfer the impact movements to the drill bit or drill bit of the outer drill string * This can thereby can be achieved * that the blow from indoor use to outdoor use over preferably truncated cone-shaped shoulders is transmitted. However, such an arrangement is subject to considerable stress on the outer strand and the Stakes connected. For this reason it is preferable to apply the striking movements directly to the drill bit of the outer Transfer drill string. For this purpose, the inner string can be provided with a drill bit through which a drill bit connected to the outer string can be driven by means of impact such that the impacts from outside use the inner string and the inner drill bit can be transferred to the outer drill bit. The drill bit of the outer drill string can be provided with axial play. The drill bit of the outer drill string can also be connected to the bottom piece of the outer drill string. Furthermore it is possible to apply the percussion movement to the outer drill bit by a combination of the two modes of transmission described transmitted so that percussion movements are transmitted both between the two inserts and between the two drill bits will.

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Preferably, the outer insert is provided with an upper part * in which the inner insert is fitted and having einem.unteren part of the _detergent} openings for a flushing agent flow between inner and outer strand. This arrangement makes it possible to mount the flushing head on the outer insert instead of on the inner insert, and as a result it is no longer necessary to provide the inner insert with axial channels for conducting the flushing agent. In such a way, both a simpler and a stronger interior insert is achieved.

Since the outdoor use is preferably not driven directly by impact, the mounting of the flushing head in the area of the detergent openings of the outdoor insert no longer subject to the high level of wear and tear as with the insert arrangements conventional kind.

Further features and advantages of the invention can be found in the following description of the figures of an exemplary embodiment »

Description of the figures In the drawing shown is

Figure 1 is a vertical section through a drill string insert assembly and the upper one Part of the drill string, with a flushing head on the outside for the purpose of supply

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detergent is provided in the space between the inner and outer line,

Fig. 2 is a cross section along the line 2-2 of Fig. 1, with sealing of the flushing openings with a clamp,

Fig. 3 is a vertical view, partly in section

of the drill with inner and outer strand and inserts according to FIG. 1, in one of the possible Working positions,

4 shows the drilling device with an arrangement for a different mode of operation, and

5 shows a view according to FIGS. 3 and 4 with the drilling device in a third mode of operation.

Fig. 1 shows an inner insert 1, which is used for rotary impact drive is connected to an energy source not shown in the drawing. The inner insert 1 is with sliding seat in the upper part of a sleeve-shaped outer insert 2 mounted and there is a seal between the two inserts in the form of ring seals 3, which are in circumferential grooves of the indoor insert.

The inner insert 1 and the hole receiving it in the outer insert have the same substantially circular cross-section, but have one or more flats provided so that the inserts cannot be rotated against each other and the inner insert drives the outer insert.

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Per inner insert 1 has a central one in a conventional manner Bore 4 for the passage of a flushing agent, normally air, through the inner drill string 5 (see FIGS. 3 to 5). This bore 4 has an enlarged lower threaded portion for receiving the upper end of the tubing string. Of the The lower part 2a of the outer insert is provided with an internal thread for receiving the uppermost piece of the outer strand 14 and the middle part of the outer insert 2 is provided with two opposing detergent openings 6, through which water or some other detergent can be fed to the space between the inner and outer strand, how is illustrated in FIG.

Around the middle part of the outer insert 2, as shown in FIGS. 1 and 4, a detachable flushing head 7 is rotatable on a lower one Bearing 9 and upper bearing 8 attached, the weight being borne by the lower bearing 9, which in turn is on a Shoulder 10 of the outdoor insert rests. The flushing head 7 can thus be lifted off from outside use when it is not in use without requiring a screw movement of clutches.

There is a conventional arrangement between the wash head and the outdoor use provided by sealing means to prevent leakage of water from the annular chamber 11 of the flushing head, the middle To prevent part of the external insert having the flushing openings 6. The rinse water is the chamber 11 fed through an inlet 12 of the valve head 7.

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Fig. 4 illustrates the operation in which the drill in connection with the removable flushing head after Fig. 1 is operated. The inner insert 1 is operated with a rotary percussion drive, whereby the drill bit of the inner drill string 13 is driven with rotary impact.

The rotary motion is imparted to the outer drill string 14 and its drill bit 15 by the rotary coupling of the two inserts transmitted while the percussion movement from the inner drill string over the frusto-conical shoulders 16 on the outer drill bit is transferred.

Rinse water that enters the chamber 11 via the inlet 12 flows, as indicated by dashed line arrows, through the Gap between the inner and outer strand and enters the rock or into the bottom between the inner and outer crown Earth a. The leakage of water from the chamber 11 after above is prevented by the seals 3. The solid arrows in Fig. 4 illustrate the path of the air through the inner drill string into the ground or rock.

The inner drill string 5 is to be removed with the drill bit 13 this can be done to advance the outer drill string by rotation alone; the flapping movement is thereby interrupted.

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- ίο -

Fig. 3 shows a mode of operation of the drilling device in which the flushing head 7 has been removed. This is, as already stated above, by simply pulling it upwards possible because it is arranged so that it can be moved vertically on the outdoor insert. Then the head can move out of its position removed from the indoor insert, either by uncoupling the insert from the power source or by lifting the Indoor use and temporary uncoupling of the insert from the topmost piece of the inner strand. After the flush head has been removed, purge air flows through the inner pipe and then up through the space between Inner and outer cord to escape through the flushing openings 6, as illustrated by the solid arrows is. Dabe ^ ind the seals 3 are not essential for the operation of the device.

Fig. 2 shows a device for sealing, which can take the place of the flushing head. This facility consists of the sentlichen from a clamp 17 with gap 18. On both sides the gap are provided with lugs 19, 20 and a bolt 21 for closing and opening the clamp. The clamp is with Openings 22 are provided which can be brought into congruence with the flushing openings 6 of the external insert. Fig. 2 shows the setting of the clamp for sealing the flushing openings 6. If the clamp is in the sealing position According to FIG. 2, the detergent flows through the space

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down between the inner and outer strands and escapes into the ground.

If the clamp is loosened and rotated so that the openings are aligned with the flushing openings 6, this results an operating mode which corresponds to the operating mode shown in FIG. The device of Fig. 2 is therefore special suitable to go from an operating mode according to FIG. 3 to an operating mode in which the scavenging air between emerges from the drill bits.

As described above, it will be where appropriate required to advance the inner drill string alone. For this purpose it is only necessary to use the interior with the inner drill string, then replace the drill bit 13 with a smaller drill bit 23 and then continue with the drilling work in the usual way, the inner liner being over the top of the outer string while the drill bit works in the rock. The drill bit 23 is made so small that that it can be passed through the annular bit of the outer drill string, the outer drill string remains in peace while drilling continues. When working with the drill according to the working method 5, the flushing takes place similarly to FIG. 3, with only the flushing air escaping at the upper end of the outer strand and not through special flushing openings 6 according to FIG. 3

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230957Ü

shows the drilling work with the external insert 2 removed. The external insert can, however, also remain in the device, since it hardly affects the operation of the drill in the manner illustrated by FIG.

The main advantage of the invention is thus that the inner insert 1 is simply lifted from the outer insert be solved) & ann without a screwing movement required is.

If the drilling device is operated as shown in Fig. 4, the flushing head is largely protected against impact vibrations, because the vibrations are only transmitted over the relatively long distance via the drill bits.

It is also of particular importance that, as can be seen from FIG is, the flushing water enters under the inner insert and as a result the inner insert does not have axial channels must be provided for the water flow.

If the outer strand is to be raised by lifting the inner insert, it is necessary to provide means through which prevents the inner liner from being pulled away from the outer liner. This can be done in the upper area the outdoor use an attack for a pair of pliers, not shown in the drawing, for example in the form of

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two-pair arranged pliers engagement holes provided be. Two of these holes 24, each belonging to one of the two pairs, are shown in FIG. The distance between the holes 24 and the associated pliers parts is little larger than the diameter of the upper part 1a of the inner insert, so that the pliers above a frustoconical Shoulder 1b of the inner liner can be engaged.

If the inner insert is lifted after the pliers have been inserted, the inner insert grips with its shoulder 1b on the pliers legs, so that it takes the outside use with it when it is lifted further.

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Claims (12)

PROTECTION EXPECTATIONS; . Drill string insert assembly for an inner drill string and an outer drill line which can be jointly advanced, characterized in that the insert assembly from a first, inner insert (1), which can be connected to the inner drill string, and a second, outer insert (2) which can be connected to the outer drill string, the second insert (outer insert 2) being the first insert (inner insert 1) axially displaceable in a bore, but does not rotate, 2. Arrangement according to claim 1, characterized in that the ■ inner insert (1) with sliding seat in the outer insert (2) is displaceable and that the corresponding engagements have a non-circular cross-section. 3. Arrangement according to claim 1 or 2, characterized in that the non-round seat in the upper part of the inner insert (2) is attached and that the outer insert (2) has a lower region (2a) in which at least one Opening (6) for the passage of a flushing agent is located, which flows through the space between the inner and outer line .. 309835/0571 4. Arrangement according to claim 3, characterized by a flushing head (7) which can be connected to the outer insert (2) and reaches the openings (6) of the outer insert (2) through flushing agent and through sealing agent (3) between the inserts, to prevent flow of detergent to the top of the insert assembly . 5. Arrangement according to claim 3, characterized by a log device (17) which can be attached to the outside of the outer insert (2) and between a position in which it closes the openings (6) in the outer insert (2) and a position in which it releases these openings (6) can be rotated. 6. Arrangement according to one of claims 1 to 5, characterized in that engagement openings (24) are provided , through the use of which the inner insert is prevented from being pulled out of the outer insert when the outer insert is to be raised by lifting the inner insert. 7. Drilling device with an inner drill string (5) and an outer drill string (14) and means for rotary percussion drive the drill string insert at z arrangement, characterized in that the drill strings (5 and 14) with an inner and outer insert (1 and 2 ) are connected according to the preceding claims , wherein the inner insert (1) is connected to the rotary percussion drive. 309835/0571 8. Drilling device according to claim 7, characterized in that the inner strand (5) is provided with a tip or crown (13) is through which a drill bit or drill bit (15) connected to the outer drill string (14) can be driven by impact is, so that the blows from the outer insert (1) over the inner string (5) and the inner drill bit (13) on the outer Drill bit (15) is transferable. 9. Drilling device according to claim 8, characterized in that the outer drill bit (15) is rigidly connected to the outer strand (14) is. 10. Drilling device according to claim 8, characterized in that the outer drill bit (15) is connected to the outer strand (14) in such a way that an axial play between the outer drill bit (15) and the inner strand (14) is present. 11. Drilling device according to one of claims 8 to 10, characterized in that the inner drill bit (13) with a truncated cone shaped shoulder (16) to engage a corresponding frustoconical shoulder (16) on the outer strand (15) is provided. 12. Drilling device according to one of claims 7 to 10, characterized in that that indoor use and outdoor use shoulders acting on one another for impact transmission from indoor use exhibit outdoor use. 309835/0571