阅读说明：本技术 用于安装套管的装置和方法 (Device and method for installing a bushing ) 是由 M·克斯金瓦 于 2019-01-21 设计创作，主要内容包括：一种用于在井孔中安装套管的装置和方法。该装置(100)包括：套管(1)；适配在套管(1)内的钻孔管(2),该钻孔管(2)包括压缩空气流动通道(3)；以及冲洗介质流动通道(4)。冲洗介质流动通道(4)布置成将冲洗介质引导到井孔底部(B)。该装置(100)还包括冲击锤(5),其包括适配在冲击锤缸体(9)内的压缩空气操纵的冲击活塞(6),以及用于为套管(1)钻出孔的钻孔设施(8)。冲洗介质流动通道(4)适于绕过冲击活塞(6),或者该冲洗介质流动通道适于穿过冲击活塞(6),在该装置中钻孔设施(8)还包括传递转动运动的花键(28),该花键适于引导冲击活塞(6)使用的压缩空气穿过所述花键。(An apparatus and method for installing casing in a wellbore. The apparatus (100) comprises: a sleeve (1); a drill pipe (2) adapted within the casing (1), the drill pipe (2) comprising a compressed air flow channel (3); and a flushing medium flow channel (4). The flushing medium flow channel (4) is arranged to direct flushing medium to the bottom of the wellbore (B). The device (100) further comprises a percussion hammer (5) comprising a compressed air operated percussion piston (6) fitted in a percussion hammer cylinder (9), and drilling means (8) for drilling a hole for the casing (1). The flushing medium flow channel (4) is adapted to by-pass the percussion piston (6) or the flushing medium flow channel is adapted to pass the percussion piston (6), in which device the drilling equipment (8) further comprises splines (28) for transmitting a rotational movement, which splines are adapted to lead compressed air used by the percussion piston (6) through said splines.)

1. An apparatus for installing casing in a wellbore, the apparatus (100) comprising:

-a bushing (1),

-a drill pipe (2) adapted within the casing (1), the drill pipe (2) comprising a compressed air flow channel (3),

-a flushing medium flow channel (4) arranged within the casing (1) and arranged to conduct flushing medium to a borehole bottom (B),

-a percussion hammer (5) comprising a compressed air operated percussion piston (6) fitted within a cylinder (9) of the percussion hammer, and

drilling means (8) for drilling a hole for the casing (1),

the flushing medium flow channel (4) is adapted to by-pass the percussion piston (6), or

In the arrangement, the drilling equipment (8) also comprises splines (28) for transmitting rotational movement, which splines are adapted to lead through the splines compressed air used by the percussion piston (6), and in the arrangement the flushing medium flow channel (4) is adapted to lead through the percussion piston (6).

2. The device according to claim 1, wherein a housing (10) is fitted on the outside of the cylinder (9) of the percussion hammer, which housing together with the wall (11) of the cylinder forms a part (12) of the flushing medium flow channel that bypasses the percussion piston (6).

3. The device according to claim 2, wherein the portion (12) of the flushing medium flow channel which bypasses the percussion piston (6) extends circularly around the cylinder (9) of the percussion hammer.

4. A device according to claim 2 or 3, wherein the housing (10) fitted on the outside of the cylinder (9) forms part of the outer surface of the impact hammer (5).

5. The device according to claim 1, wherein one or more pipes (13) are fitted on the outside of the cylinder (9) of the percussion hammer, which pipes form the part (12) of the flushing medium flow channel that bypasses the percussion piston (6).

6. The device according to any of the preceding claims, wherein the part (12) of the flushing medium flow channel which bypasses the percussion piston is connected at its top end to an adapter (14) of the drill pipe, which adapter has an adapter flow channel (15) which is arranged to distance the flushing medium flow channel (4) further away from the longitudinal centre axis (X) of the device.

7. The device according to claim 5, wherein the device further comprises at least one collar (30) connected to the casing (1) or to a casing shoe (31) fixed to the casing (1), wherein the portion (12) of the flushing medium flow channel bypassing the percussion piston (6) is connected to the at least one collar (30) by its bottom end.

8. The device according to claim 7, wherein the at least one ferrule (30) further comprises at least one locking means (32, 32b) for locking the at least one ferrule (30) to the casing (1) or the casing shoe (31).

9. The device according to claim 8, wherein the at least one locking member (32) is adapted to lock the at least one ferrule (30) to the cannula (1) or the cannula shoe (31) by means of a pressurized flushing medium.

10. The device according to claim 8, wherein the at least one locking member (32) comprises a pressure line (33) adapted to lock the at least one ferrule (30) to the casing (1) or the casing shoe (31).

11. The device according to any of the preceding claims, wherein the percussion hammer (5) comprises a bottom member (16) having at least one bottom member flushing medium flow channel (17) adapted to be in flow connection with the portion (12) of the flushing medium flow channel that bypasses the percussion piston, and wherein:

the drilling installation (8) comprises at least one drilling installation flushing medium flow channel (18) adapted to be in flow connection with the bottom member flushing medium flow channel (17) and to guide flushing medium to the borehole bottom (b).

12. The device according to claim 11, wherein the bottom member flushing medium flow channel (17) comprises a circular flow groove (19) adapted on an inner surface of the bottom member (16), which circular flow groove encircles in a plane of the inner surface at least substantially perpendicular to the longitudinal centre axis (X) of the device.

13. The device according to claim 12, wherein a seal (20) is adapted on both sides of the circular flow groove (19).

14. The device according to claim 1, wherein the drilling equipment (8) comprises at least one drilling equipment flushing medium flow channel (18) adapted to conduct flushing medium from the flushing medium flow channel (4) to the borehole bottom (B), and in the device the flushing medium flow channel (4) is adapted to pass through the percussion piston (6).

15. The device according to any of the preceding claims 1-13, wherein compressed air used by the percussion piston (6) is removed through an exhaust channel (21) comprising a central opening (22) in the drilling equipment (8), which central opening is flow-connected to the cylinder (9) of the percussion hammer, and which exhaust channel comprises at least one air channel (23) passing from the central opening (22) radially through the bottom member (16) of the percussion hammer, which air channel is flow-connected with the space between the percussion hammer (5) and the casing (1).

16. The device according to any of the preceding claims 1 to 14, wherein the drilling equipment (8) further comprises splines (28) transferring rotational movement, said splines being adapted to guide compressed air used by the percussion piston (6) through said splines (28).

17. The device according to any one of claims 1 to 14 or 16, wherein compressed air driving the impact piston (6) is removed through an exhaust channel (21) comprising:

-at least one lateral exhaust channel (24) led over the drilling installation (8), which is in flow connection with the cylinder (9) of the percussion hammer, and

-an air flow channel (25) in flow connection with the at least one side exhaust channel (24), and

at least one air channel (23) passing radially through the base member (16) of the hammer from the air flow channel (25) in flow connection with the space between the hammer (5) and the sleeve (1).

18. Device according to claim 17, in which the side exhaust channels (24) are formed between splines (28).

19. The device according to claim 17 or 18, wherein the circular air flow channel (25):

-is fitted on the inner surface of the bottom member (16),

-adapted to abut against the drilling equipment (8), and

-a portion around the drilling equipment in a plane at least substantially perpendicular to the longitudinal centre axis X of the device.

20. A method for installing casing using an apparatus comprising a casing (1) and a drill pipe (2), a percussion hammer (5) and a drilling installation (8), in which method,

-rotating the drill pipe (2) within the casing (1),

-driving the impact hammer (5) by compressed air, and

-flushing the borehole bottom by means of a flushing medium which is led from the drilling pipe (2) over the percussion piston (6) of the percussion hammer to the drilling equipment (8) and further to the borehole bottom (B), or

Flushing of the borehole bottom (B) by means of a flushing medium led through the impact piston (6) to the drilling equipment (8) and further to the borehole bottom (B), in which arrangement the drilling equipment (8) also comprises splines (28) transmitting a rotational movement, whereby compressed air driving the impact piston (6) is led through the splines 28.

Technical Field

The present invention relates to a device for installing a bushing.

The invention also relates to a method for installing a bushing.

Background

An effective method of installing casing or rod into hard earth formations (e.g. when partially driving casing into rock) is percussive drilling. In this case, the casing has a drill pipe inside it and an impact hammer, such as a down-the-hole hammer or DTH hammer, at the end of the drill pipe. The drill pipe has a central opening through which the compressed air required for the DTH hammer is supplied. A rotation mechanism at the top end of the drill pipe rotates the drill pipe, the DTH hammer, the guide crown and the drill connected to the guide crown simultaneously.

The drilling of the hole is performed by the impact function generated by the hammer and the rotation of the drill pipe. The purpose of the reamer is to enlarge the hole formed by the guide crown to a size that allows the casing to fit into the drilled hole. The casing may also have so-called casing shoes (casing shoe) by means of which the guide crown pulls the casing with it into the drilled hole. The removal of the released material is accomplished by venting of the DTH hammer. Here, the exhaust air of the DTH-hammer is led by means of a hole in the guide crown to the bottom of the hole being drilled, where the air flow carrying the released material is led as far as possible to the interior of the casing and further from the casing to the surface.

The problem here is that usually part of the air flow will inevitably escape to the ground. Excessive air leakage can significantly reduce the bearing strength around the ground, thereby posing a risk to surrounding structures, such as the foundation of a building.

The escape of air to the ground can be partially controlled by the design of the guiding crown. In particular, a crown in which the flushing air blown to the bottom of the hole is diverted parallel to the bottom of the hole before it is expelled from the crown reduces the escape of air into the formation.

In addition, it is more efficient to use a separate flushing circuit, in which the borehole is not flushed by means of exhaust air, but water or another similar flushing medium is used. This enables the use of so-called RC drilling systems (reverse circulation). RC drilling systems were originally developed to study drilling in which the bulk material produced by drilling was washed up from the bottom of the hole along the central opening of a two-layer drill pipe, thereby storing the bulk material for later analysis.

The RC system is comprised of an RC drill pipe and an RC hammer. RC drill pipes generally have an outer pipe and an inner pipe, wherein the inner opening of the inner pipe and the space between the outer pipe and the inner pipe form two separate flow channels. The operation of the actual RC hammer is the same as that of the normal DTH hammer. The RC hammer has a tube passing through the hammer, along which the exhaust of the hammer carries the released material through the hammer. The impact piston of the hammer has a relatively large central opening for the tube so that the tube and air flow passage (necessary for operation of the DTH hammer) can fit through the impact piston.

RC drilling systems may be suitable for use in earth boring when it is desired to prevent air from escaping to the surface.

In this case, the RC drill pipe is used to supply the RC hammer with the operating compressed air required for the RC hammer, as well as a flushing medium, such as water. The flushing medium is typically supplied through the inner opening of the inner tube, and compressed air is supplied through the space between these tubes. The exhaust of the RC hammer is supplied into the casing through the bit crown, which exits from the casing to the ground. The flushing medium supplied through the pipe through the RC hammer also passes through the bit crown to the bottom of the hole where it flushes the released material. Thereafter, the flushing medium and the released material are transported to the surface along the gap between the casing and the hole.

The method of using the RC drilling system is best suited for drilling locations that do not allow air to escape into the formation at all. However, the problem is that the pipe passing through the RC hammer requires an impact hammer with a relatively large central opening. This significantly reduces the mass of the piston and the pneumatic working surface of the reciprocating piston. In other words, the RC hammer produces drilling power significantly lower than that of a conventional DTH hammer.

Disclosure of Invention

The device and the method of the invention are characterized by what is disclosed in the independent claims. Other embodiments of the invention are characterized by what is disclosed in the remaining claims.

Inventive embodiments are also disclosed in the description and drawings of the present application. The inventive content of the application can also be defined differently than in the claims presented below. The inventive content may also consist of several separate inventions, especially if the invention is examined in light of disclosed or implied sub-tasks or from the advantages or groups of advantages obtained. In this case, some of the limitations in the following claims may not be relevant to a single point of invention. The features of the different embodiments of the invention may be applied to other embodiments within the scope of the basic inventive idea.

According to one concept, an apparatus for installing casing in a wellbore comprises: a casing and a borehole tube adapted within the casing, the borehole tube comprising a compressed air flow passage and a flushing medium flow passage, the flushing medium flow passage being arranged to direct flushing medium to the bottom of the wellbore; and a percussion hammer comprising a compressed air operated percussion piston adapted to be within a cylinder of the percussion hammer; and drilling means for drilling a hole for the casing. The flushing medium flow channel is adapted to bypass the percussion piston.

An apparatus for installing casing in a wellbore according to one embodiment comprises: a casing and a borehole tube adapted within the casing, the borehole tube including a flow passage for compressed air. The device also includes: a flow passage for a flushing medium adapted within the casing and arranged to direct the flushing medium to the bottom of the wellbore; and a percussion hammer comprising a compressed air operated percussion piston adapted to be within a cylinder of the percussion hammer; and drilling means for drilling a hole for the casing. The flushing medium flow passage is adapted to bypass the percussion piston; or in the device the drilling equipment further comprises splines transmitting rotational motion and adapted to lead compressed air used by the percussion piston through said splines, and in the device the flushing medium flow channel is adapted to lead through the percussion piston.

An apparatus for installing casing in a wellbore according to one embodiment comprises: a casing and a borehole tube adapted within the casing, the borehole tube comprising a flow channel for compressed air and a flow channel for a flushing medium, the flow channel for the flushing medium being adapted within the casing and arranged to direct the flushing medium to the bottom of the borehole; and a percussion hammer comprising a compressed air operated percussion piston adapted in a cylinder of the percussion hammer; and drilling means for drilling a hole for the casing. The flushing medium flow passage is adapted to bypass the percussion piston; or in the device the drilling equipment further comprises splines transmitting the rotational movement and adapted to lead compressed air used by the percussion piston through said splines, and in the device the flushing medium flow channel is adapted to lead through the percussion piston.

According to a second idea, a method of installing a casing using a device comprising a casing and a drill pipe and an impact hammer and a drilling apparatus, in which method the drill pipe is rotated inside the casing, the impact hammer is used by means of compressed air, and the bottom of the borehole is flushed by a flushing medium which is led from the drill pipe past the impact piston of the impact hammer to the drilling apparatus and further to the bottom of the borehole.

According to one idea, a method for installing a casing uses a device comprising a casing and a drill pipe and an impact hammer and a drilling apparatus, in which method the drill pipe is rotated inside the casing, the impact hammer is used by means of compressed air, and the bottom of the borehole is flushed by a flushing medium which is led past the impact piston of the impact hammer to the drilling apparatus and further to the bottom of the borehole; or by means of a flushing medium which is led through the percussion piston to the drilling equipment and further to the borehole bottom, and in which device the drilling equipment also comprises splines which transmit the rotary motion, whereby the compressed air used by the percussion piston is led through the splines.

In the following, some embodiments of the invention are presented in any order.

According to one embodiment, a housing is fitted outside the cylinder of the percussion hammer, which housing together with the cylinder wall forms a part of the flushing medium flow channel, which part bypasses the percussion piston.

According to one embodiment, the part of the flushing medium flow channel which bypasses the percussion piston extends circularly around the cylinder of the percussion hammer.

According to one embodiment, the housing, which fits on the outside of the cylinder, forms part of the outer surface of the impact hammer.

According to one embodiment, one or more pipes are fitted on the outside of the cylinder of the percussion hammer, which pipes form part of the flushing medium flow channel bypassing the percussion piston.

According to one embodiment, the part of the flushing medium flow channel bypassing the percussion piston is connected by its top end to an adapter of the drill pipe, the adapter having an adapter flow channel configured to distance the flushing medium flow channel further from the longitudinal centre axis of the device.

According to one embodiment the device further comprises at least one ferrule connected to the casing or to a casing shoe fixed to the casing, wherein the part of the flushing medium flow channel bypassing the impulse piston is connected to the at least one ferrule by its bottom end.

According to one embodiment, at least one ferrule of the device further comprises at least one locking member for locking said at least one ferrule to the casing or the casing shoe.

According to one embodiment, the at least one locking member is adapted to lock the at least one ferrule to the cannula or the cannula shoe by means of a pressurized flushing medium.

According to one embodiment, the at least one locking member comprises a pressure line adapted to lock the at least one ferrule to the casing or the casing shoe.

According to one embodiment, the percussion hammer comprises a bottom member having at least one bottom member flushing medium flow channel adapted to be in flow connection with the part of the flushing medium flow channel that bypasses the percussion piston, wherein the drilling equipment comprises at least one drilling equipment flushing medium flow channel adapted to be in flow connection to the bottom member flushing medium flow channel and to guide the flushing medium to the bottom of the borehole.

According to one embodiment, the flow channel of the bottom member comprises a circular flow groove which fits on the inner surface of the bottom member and which surrounds in the plane of said inner surface, which is at least substantially perpendicular to the longitudinal centre axis of the device.

According to one embodiment the width of the circular flow groove, i.e. the dimension of the device in the direction of the longitudinal centre axis, is arranged to be wide enough so that the flushing medium flow channel remains open throughout the entire period of the drilling operation, irrespective of the movement of the drilling equipment.

According to one embodiment, a seal is fitted on both sides of the circular flow groove.

According to one embodiment the drilling equipment comprises at least one drilling equipment flushing medium flow channel adapted to lead flushing medium from the flushing medium flow channel to the bottom of the borehole, and in the device the flushing medium flow channel is adapted to pass through the flushing piston.

According to one embodiment, the compressed air used by the percussion piston is removed through an exhaust channel, which comprises a central opening in the drilling installation, which central opening is in flow connection with the cylinder of the percussion hammer, and which exhaust channel comprises at least one air channel, which passes through the bottom member of the percussion hammer in the radial direction, which air channel is in flow connection with the space between the percussion hammer and the casing.

According to one embodiment, the drilling equipment further comprises splines transferring rotational movement and adapted to lead compressed air used by the percussion piston through said splines.

According to one embodiment, the compressed air used by the percussion piston is removed by an exhaust channel, which comprises at least one lateral exhaust channel led over the drilling installation, which lateral exhaust channel is in flow connection with the cylinder of the percussion hammer, and which exhaust channel comprises an air flow channel in flow connection with the at least one lateral exhaust channel and at least one air channel passing radially through the bottom member of the percussion hammer, which air channel is in flow connection with the space between the percussion hammer and the sleeve.

According to one embodiment, the side exhaust channels are formed between the splines.

According to one embodiment, the circular flow groove adapted on the inner surface of the bottom member and facing the drilling equipment is surrounded in the plane of a part of said inner surface, which is at least substantially perpendicular to the longitudinal centre axis of the device.

According to one embodiment, the impact hammer is a DTH hammer.

Drawings

The invention is described in more detail in the accompanying drawings, in which:

figure 1 is a schematic side sectional view of a device for installing a bushing,

figure 2a is a schematic cross-sectional side view of a second apparatus for installing a bushing,

figure 2b shows a section a-a of the device of figure 2a,

figure 3a is a schematic side sectional view of a third arrangement for installing a bushing,

figure 3b is a schematic side sectional view of a detail of the device of figure 3a,

figure 4a is a schematic cross-sectional side view of a device for installing a bushing,

figure 4b is a schematic side sectional view of a detail of the device of figure 4a,

figures 5a to 5c are side cross-sectional views of alternative details of the band of the device of figures 4a and 4b,

figure 6 is a schematic side sectional view of a detail of the device,

figure 7a is a schematic cross-sectional side view of a device for installing a bushing,

FIG. 7b is a schematic cross-sectional side view of a detail of the device of FIG. 7a, an

Figure 8 is a side view of a detail of the band of the device.

For the sake of clarity, the figures show the invention in a simplified manner. Similar components are denoted by the same reference numerals in the figures.

Detailed Description

Fig. 1 is a schematic side sectional view of a device for installing a bushing.

The apparatus 100 comprises a casing 1, which is a tubular member that is typically permanently installed in the ground. In the installation phase of the casing 1, the drill pipe 2 has been fitted inside it to rotate inside the casing. The device 100 also comprises a percussion hammer 5 operated by compressed air. For this purpose, the device 100 has a flow channel 3 for compressed air. The bottom X of the wellbore is flushed by a flushing medium supplied to the bottom B of the wellbore through the flow channel 4.

The flushing medium may be water, an aqueous mixture, such as drilling mud, or another suitable substance in a flowing form.

The hammer 5 shown in fig. 5 is a compressed air operated DTH hammer (down-the-hole hammer). Obviously, the impact hammer 5 may be a hammer other than a DTH hammer in consideration of its basic principle.

It should be noted, however, that these figures only show the hammer components necessary for the present invention. These figures illustrate one embodiment of a DTH hammer that does not use a foot valve (foot valve) mounted to the tip of the pilot crown. The device according to the invention is also suitable per se for embodiments provided with a foot valve.

The percussion hammer 5 comprises a compressed air operated percussion hammer 6 which is adapted to a cylinder 9 of a percussion hammer which can be moved to and fro.

The apparatus 100 further comprises a drilling arrangement 8, which drilling arrangement 8 is used to drill a hole in the formation for the casing 1. In the embodiment shown in the figures, drilling apparatus 8 comprises a guide crown 26 and a reamer 27. The drilling equipment 8 may be shaped in another way: in one embodiment, the drilling installation 8 comprises a so-called wing reamer, in other words a bit crown with open wings.

In the device the flushing medium flow channel 4 is adapted to bypass the percussion piston 6 of the percussion hammer 5. The advantage of this arrangement is that flushing of the borehole bottom B can be carried out efficiently using a separate flushing circuit, while the drilling power of the percussion piston is high due to the large mass and large pneumatic working area of the percussion piston. According to one concept, it is noted that the advantages of the DTH hammer and the RC hammer have been combined.

In the embodiment shown in fig. 1, the flushing medium flow channel 4 comprises a portion 12 which bypasses the percussion piston 6 and extends in a circular manner around the cylinder 9 of the percussion hammer. Said portion 12 of the flow channel is formed by fitting a tubular housing 10 around the cylinder 9. The housing may be formed of steel or the like. According to fig. 1, the housing 10 fitted outside the cylinder 9 may constitute a part of the outer surface of the impact hammer 5, but this is not mandatory.

The portion 12 which bypasses the percussion piston is connected at its top end to an adapter 14 of the drill pipe which connects the drill pipe 2 to the percussion hammer 5. The drill pipe adapter 14 has an adapter flow channel 15, which adapter flow channel 15 is arranged to distance the flushing medium flow channel 4 further from the longitudinal centre axis of the device, whereby said part 12 of the flow channel is advantageously flow-technically connected to the flushing medium channel in the drill pipe.

The percussion hammer 5 comprises a bottom member 16, which bottom member 16 has at least one bottom member flushing medium flow channel 17 adapted to be in flow connection with said portion 12 of the flushing medium flow channel bypassing the flushing piston. In one embodiment, the number of flushing medium flow channels 17 is three. The task of the bottom element flushing medium flow channel 17 is to guide flushing medium from the structure of the percussion hammer 5 to the drilling equipment 8.

The drilling equipment 8 of the hole comprises at least one drilling equipment flushing medium flow channel 18 which leads flushing medium to the bottom B of the borehole. In one embodiment, the number of drilling installation flushing medium flow channels 18 is three.

In the embodiment of fig. 1, the flow passage 18 opens substantially parallel to the central axis X of the borehole bottom B. This accomplishes an effective flush directly to the well bottom B. In certain other embodiments, the flow channels 18 open at significantly different angles with respect to the central axis, whereby flow in the direction of the bottom of the well may be enhanced. In the third embodiment, there are a plurality of flow channels 18 that point in different directions from each other.

In the embodiment of the figure, the flow channel 17 of the base member comprises a circular flow groove 19 which fits on the cylindrical inner surface of the base member 16 and circles (circles) in a plane of said inner surface which is at least substantially perpendicular to the longitudinal centre axis X of the device. The width of the circular flow groove 19, i.e. the dimension of the device in the direction of the longitudinal centre axis X, is arranged to be wide enough so that the flushing medium flow channel 4 remains open throughout the entire period of the drilling operation, irrespective of the movement of the drilling equipment 8. The drilling equipment 8 is moved by the impact of the impact piston in the direction of the centre axis X in the manner shown by the arrow M, and in addition the drilling equipment 8 is rotated around the centre axis X.

On both sides of the circular flow groove 19, seals 20 (shown in fig. 2 a) are advantageously mounted in order to prevent flushing medium from escaping from the flushing medium channel.

The impact piston 6 is operated by compressed air supplied from the compressed air flow passage 3 to the hammer cylinder 9. In the embodiment of fig. 1, the compressed air operating the percussion piston 6 is removed from the cylinder 9 through an exhaust channel 21, which exhaust channel 21 comprises a central opening 22 in the drilling equipment 8. This is in flow connection with at least one air channel 23 passing through the striker base part 16 in the radial direction, which channel 23 is in turn in flow connection with the space between the striker 5 and the bushing 1. Air exits the space at the top end of the sleeve 1.

Fig. 2a is a schematic side sectional view and fig. 2b is a cross-section a-a of a second device for installing a bushing. In this embodiment, the flushing medium flow channel is implemented in the same way as in the embodiment of fig. 1. While the arrangement for the removal of compressed air is different. The compressed air driving the percussion piston 6 is now removed by the exhaust channel 21, which exhaust channel 21 comprises at least one lateral exhaust channel 24, which is led over the drilling equipment 8 and in flow connection with the cylinder 9 of the percussion hammer.

The advantage is that there is no need to drill or otherwise machine channels for exhaust gases in the drilling installation 8 which would reduce its robustness.

Fig. 2b shows an embodiment in which the side exhaust channels 24 are formed between splines 28, the splines 28 transferring the rotational movement to the drilling equipment 8.

The vent passage 21 also includes a circular air flow passage 25 that fits over the inner surface of the base member 16. The circular air flow channel 25 surrounds said inner surface in a plane at least substantially perpendicular to the longitudinal centre axis X of the device.

The width of the circular flow groove 25, i.e. the dimension of the device in the direction of the longitudinal centre axis X, is large enough so that the flow channel 21 remains open throughout the entire period of the drilling operation, irrespective of the movement of the drilling equipment 8.

The circular air flow channel 25 is in flow communication with the at least one air discharge channel 24 and at least one air channel 23 through the striker base member 16, which channel 23 is in turn in flow communication with the space between the striker 5 and the casing 1. Air comes out of the space in the manner already explained.

Fig. 3a is a schematic side section view of a second device for installing a bushing, and fig. 3b is a view thereof in detail from the side. According to one idea, the portion 12 of the flushing medium flow channel, which portion bypasses the percussion piston 6, is formed by using a pipe 13 fitted outside the percussion hammer cylinder 9. In the embodiment of fig. 3a, there is one tube 13, but obviously there may be more.

The advantage is that the flushing medium flow channel 4 can be implemented in a very simple manner.

In other respects, the flushing medium flow channel 4 is embodied just as in the embodiment of fig. 1.

The exhaust channel 21 comprises an air channel 23 formed in the drilling equipment 8 and a channel leading from the drilling equipment to the bottom member 16 and further through the bottom member.

Fig. 4a is a schematic side sectional view of a device for mounting a bushing, and fig. 4b is a detail thereof taken from the side. In this embodiment the flushing medium flow channel 4 may be implemented by a part 12 of the flow channel as in fig. 3a, which part is preferably a tube 13 or a hose. In fig. 3a, the tube 13 is connected by its top end to the adapter 14 of the drill pipe, whereby it rotates together with the drill pipe 2. In the embodiment of figures 4a and 4b, the tube 13 may be connected by its lower end to at least one ferrule 30, which is preferably circular, whereby the tube 13 cannot rotate with the drill pipe 2. The ferrule 13 may be connected or fastened to the casing 1 or a drill shoe 31 connected to the casing 1 by at least one locking member 32, such as a sleeve. The tightening or locking of the band 30 can also be implemented by symmetrically arranged locking parts 32. The locking member 32 may be formed of rubber or another suitable flexible material. The tube 13 may be secured to the casing 1 in a fixed and non-rotating manner, whereby it does not rotate with the drill pipe 2. By means of the locking member 32 the ferrule 30 can be locked and sealed to the casing 1, whereby it can direct all flushing medium to the bottom B of the borehole. The device 100 may also include one or more seals 38 to prevent water from contacting other structures.

By using a solution in which the flushing medium is guided over the percussion piston 6 by the non-rotating pipe 13, significant cost savings are achieved, since standard percussion hammers 5 and drill pipes 2 can be used without new ones being manufactured as a result. Furthermore, the flushing medium can be supplied via the usual pipe 13 and a pump. After drilling is complete, the pipe 13 may also be used to inject grout into the bottom B of the drilled hole to reinforce the drilled hole.

In the embodiment according to fig. 4a and 4b, the removal of compressed air can be arranged as in the embodiment shown in fig. 2 a. The impact piston 6 is operated by compressed air supplied from the compressed air flow passage 3 to the hammer cylinder 9. The compressed air driving the percussion piston 6 is removed through the exhaust channel 21, which exhaust channel 21 comprises at least one lateral exhaust channel 24, which is led over the drilling equipment 8 and in flow connection with the cylinder 9 of the percussion hammer. The vent passage 21 includes a circular air flow passage 25 that fits over the inner surface of the base member 16. A circular air flow passage 25 is in flow connection with the at least one lateral exhaust passage 24 and at least one air passage 23 through the striker base member 16, which passage 23 in turn is in flow connection with the space between the striker 5 and the casing 1 from which air exits at the top end of the tube.

In the embodiment according to fig. 4a and 4b, the removal of compressed air may also be arranged such that the side exhaust channels 24 are formed between the splines 28, the splines 28 transmitting the rotational movement to the drilling equipment 8, as described in the embodiment of fig. 2 b.

Figures 5a to 5c are side sectional views of alternative details of the band 30 of the device of figures 4a and 4 b. For the sake of clarity, fig. 5a to 5c do not show the exhaust channel 21, which exhaust channel 21 may be according to the details shown in fig. 4a and 4 b. In the embodiment of fig. 5a, the band 30 may include a locking member 32. The band 30 and the locking member 30 may be circular and encircle the inner surface of the sleeve 1. The ferrule 30 is attached to the casing 1 or to a casing shoe 31 attached to the casing. A locking member 32 may be located on the outer surface of band 30 against sleeve 1 to secure and seal band 30 and prevent it from rotating with guide crown 26. The at least one locking member 32 may be adapted to lock the at least one ferrule 30 to the cannula 1 or the cannula shoe 31 by means of a pressurized flushing medium. The locking part 32 may comprise an open inner part 35, as shown in fig. 5a, or the inner part may be solid. The open inner part 35 allows the flushing medium to be able to access the interior of the locking part 32. It is easier and more economical to manufacture the locking part 32 with the open inner part 35. By means of the pressure-limiting valve 34 it is possible to raise the pressure of the flushing medium to a suitable extent and lock the band 30 to the casing 1 in a non-rotating manner. The pressure is preferably 4 bar. As shown in fig. 5a, pressurized flushing medium may be led from the tube 13 to the locking member 30, where the locking member 32 is pressurized against the sleeve. According to one embodiment, the removal of compressed air may be provided by splines 28 which transmit rotational motion. The flow of flushing medium is shown by arrows F and the removal of compressed air by arrows R.

According to the embodiment shown in fig. 5b, the locking and sealing of the band 30 can be performed by a locking member 32, wherein a pressurization can be carried out on a separate pressure line 33 of the locking member. A pressurized substance is carried through the pressure line 33 according to arrow S to lock and seal the ferrule 30 relative to the sleeve 1. By means of the seal 20, the leakage gap between the band 30 and the guiding crown 26 can be sealed, preventing water from entering the interior of the casing. In the embodiment in fig. 5b, the locking member 32 comprises a closed inner member. Fig. 5c shows the device according to fig. 5b, wherein the locking part 32 comprises an open inner part 35.

Fig. 6 is a schematic side sectional view of a detail of the device. For the sake of simplicity of the drawing, the casing 1 or the casing shoe 31 is not shown. According to fig. 4a and 4b, the flushing medium is brought along the tube 13 to the collar 30, the collar 30 being non-rotatably locked to the casing 1 or the casing shoe 31. In this arrangement, the percussion hammer 5 comprises a guide crown 26 with or without a foot valve 36. The pressurized exhaust gases R may be passed through a central opening 22 arranged through a guide crown 26 and removed through at least one air channel 23 to the space between the impact hammer 5 and the casing 1.

Figure 8 is a side view of a detail of the band 30 of the device. Fig. 8 depicts a device similar to that of fig. 5a to 5b, but with the locking of the band 30 provided in an alternative manner. The tube 13 may be connected by its bottom end to at least one ferrule 30. The ferrule 30 may be connected or fastened to the sleeve 1 or a sleeve shoe 31 connected to the sleeve 1 by at least one locking member 32 b. The locking means 32b may comprise a mechanical lock between the sleeve shoe 31 and the ferrule 30, such as the device of fig. 8 (getting). According to one embodiment, the locking means 32b may comprise at least one rib, protrusion or pin fixed by welding, for example on the inner surface of the casing 1 or the casing shoe 30. Similarly, at least one groove may be formed on the outer surface of the ferrule 30 to lock the ferrule 30 to a rib, protrusion or pin of the sleeve 1 or sleeve shoe 31 in a non-rotational manner. The tightening or locking of the band 30 can also be implemented by symmetrically arranged locking parts 32 b.

Fig. 7a is a schematic side sectional view of a device for mounting a bushing. Fig. 7b is a schematic side sectional view of a detail of the device of fig. 7 a. Unlike fig. 1 to 6, the bottom B of the borehole may be flushed by a flushing medium which is led through the percussion piston 6 along a flushing medium pipe 39 in the central opening 22 to the drilling equipment 8 and further along the flushing medium flow channel 18 of the drilling equipment to the bottom B of the borehole. In the embodiment according to fig. 7a and 7b, the removal of compressed air can be provided by means of the side exhaust channel 24 according to fig. 2 a. In one embodiment, the side exhaust channels 24 are formed between splines 28, the splines 28 transmitting the rotational movement to the drilling equipment 8, as described in the embodiments of fig. 2b, 4a, 4b, 5a to 5 b.

The apparatus 100 may be used according to, for example, the following methods:

-rotating the drill pipe 2 inside the casing 1,

a percussion hammer 5 driven by compressed air, and

flushing of the borehole bottom B by flushing medium conducted from the drilling pipe 2 over the percussion hammer's percussion piston 6 to the drilling equipment 8 and further to the borehole bottom B; or by flushing of the borehole bottom B by flushing medium led through the impact piston 6 to the drilling equipment 8 and further to the borehole bottom B, and the drilling equipment 8 in the device further comprises splines 28 transmitting the rotational movement, whereby the compressed air driving the impact piston 6 is led through these splines 28.

In some cases, the features disclosed in this application may be used as well, irrespective of other features. On the other hand, the features disclosed in the present application may be combined as necessary to provide different combinations.

The drawings and the related disclosure are intended to be merely illustrative of the inventive principles. It is obvious to the person skilled in the art that the invention is not limited to the embodiments described above, in which the invention is disclosed by way of examples, but that various modifications and different applications of the invention are possible within the inventive concept defined in the appended claims.

Reference numerals:

1 casing tube

2 drilling pipe

3 compressed air flow channel

4 flushing medium flow channel

5 impact hammer

6 impact piston

8 drilling facility

9 impact hammer cylinder

10 casing

11 cylinder wall

12 parts of flow channel

13 pipe

14 bore pipe adapter

15 adapter flow channel

16 impact hammer bottom member

17 flushing medium flow channel of bottom part

Flushing medium flow channel for 18-hole drilling installation

19 circular flow groove

20 sealing element

21 exhaust passage

22 central opening

23 air channel

24 side exhaust passage

25 circular air flow channel

26 guide crown

27 underreamer

28 spline

30 hoop

31 casing shoe

32. 32b locking member

33 pressure line

34 pressure limiting valve

35 open interior parts

36 distribution valve

37 damper

38 seal

39 flushing medium pipe

100 device

Bottom of B well

F flushing medium

P compressed air

R exhaust

Longitudinal central axis of X device