WO2004013456A1

WO2004013456A1 - Drilling arrangement

Info

Publication number: WO2004013456A1
Application number: PCT/AU2003/000990
Authority: WO
Inventors: Robert Courtney-Bennett
Original assignee: Robert Courtney-Bennett
Priority date: 2002-08-05
Filing date: 2003-08-05
Publication date: 2004-02-12
Also published as: AU2002950577A0

Abstract

A drilling arrangement comprising an outer tube (11) and inner tube (17) which are intended to be received in a bore hole, the annular space between the tubes being adapted to be connected to a source of pressurised fluid, the inner tube being connected to an exhaust, a valve (31) provided between the tubes to control fluid to flow into the bore hole whereby relative movement between the inner and outer tubes open and close the valve to enable the pressurised fluid to be delivered into the bore hole as desired.

Description

"Drilling Arrangement"

Field of the Invention

This invention relates to a drilling arrangement.

Background

In the drilling of bore holes it is a common characteristic to utilise an outer tube or casing and drill string which is accommodated within the casing which is used to form the hole whilst allowing the casing to progress with the hole. The use of the casing is particularly relevant in loose or non-consolidated ground, which in the absence of the casing will collapse around the drill string.

In addition in many instances it may be necessary to utilise a dual pipe tube system to take into account the differing ground formations while also using the inner tube to transport the exhaust fluid and entrained cuttings to the surface. This technique is particularly relevant when drilling in loose or non-consolidated ground whereby the outer tube acts as a casing and the space between the inner and outer tube is used to deliver fluid to the drill bit from the surface.

If subsequently the bore hole is to be used for the purposes of extraction of water or the like from the ground it is usual practice to, subsequent to the drilling of the hole, introduce a fluid conduit into the bore hole through the inner tube and on location of the tube in position the inner and outer tube are removed from the hole. This procedure requires the use of a large diameter inner tube and thus a large diameter outer tubes and drill bit in order that the fluid conduit and its connectors can be accommodated within the inner tube. As the diameters increase so too does the amount of air that must be delivered into the drill string because of the increased volume of the drill string.

The above description of the background is not intended to limit the scope or application of the invention. Dϊsclosure of the Invention

According to one aspect the invention resides in a drilling arrangement comprising an outer tube and inner tube which are intended to be received in a bore hole, the annular space between the tubes being adapted to be connected to a source of pressurised fluid, the inner tube being connected to an exhaust, a valve provided between the tubes to control fluid to flow into the bore hole whereby relative movement between the inner and outer tubes open and close the valve to enable the pressurised fluid to be delivered into the bore hole as desired.

According to a preferred feature of the invention the inner tube is removable from within the outer tube and is adapted to engage the valve member and remove the valve member from the outer tube.

According to a second aspect the invention resides in a drilling arrangement comprising an outer and inner tube, the lower end of the inner tube is intended to be provided with a drilling element, the annular space between the tubes being adapted to be connected to a source of pressurised fluid, the inner tube being connected to an exhaust of the drilling element, a valve provided between the tubes to control fluid to flow into the bore hole whereby relative movement between the inner and outer tubes open and close the valve to enable the pressurised fluid to be delivered into the bore hole as desired.

According to a third aspect the invention resides in a drilling arrangement comprising an outer tube and inner tube, the lower end of the inner tube is intended to be provided with a drilling element, the annular space between the tubes being adapted to be connected to a source of pressurised fluid, the interior of the inner tube being adapted to be connected to an exhaust, a valve provided between the tubes to control fluid to flow into the bore hole whereby relative movement between the inner and outer tubes open and close the valve, to enable fluid to flow to the drilling element when the drilling element is active or inactive and to at least reduce the fluid flow to the drilling element when the drilling element is inactive or active respectively. According to a preferred feature of the invention the valve is open when the drilling element is active and the valve is closed when the drilling element is inactive. According to a preferred feature of the invention the pressurised fluid is delivered to the drilling element.

According to a preferred feature of the invention the drilling element comprises a rotary bit. According to one embodiment the rotary bit comprises a blade bit. According to another embodiment the rotary bit comprises a diamond bit. According to another embodiment the rotary bit comprises a tricone bit.

According to a preferred feature of the invention the valve comprises an annular seat supported by one of the tubes, and an annular valve member supported between the inner and outer tubes and the seat whereby relative axial displacement between the tubes in one or the other direction will cause the sealing element to move into and out of sealing engagement with the tubes. According to a preferred feature of the invention the seat comprises an annular element formed with a plurality of angularly spaced lugs. According to a preferred feature of the invention the seat is supported from the inner face of the outer tube. According to a preferred feature of the invention the inner tube is removable from within the outer tube and is adapted to engage the valve member and remove the valve member from the outer tube.

According to a preferred feature of the invention the outer walls of the inner tube inward of the seat are divergent. According to an alternative preferred feature of the invention rein the outer wall of the inner tube inward of the seat are parallel.

According to a preferred feature of the invention the inner tube is formed with at least one port extending between the inner and outer face, said at least one port being located outward of the valve.

According to a preferred feature of the invention the inner the valve is closed when the drilling element is active and the valve is open when the drilling element is inactive, said drilling element when active utilising pressurised fluid from the annular space which is bypassed past the valve, said pressurised fluid being delivered into the bore hole around the drilling element when the valve is open. According to one embodiment the drilling element comprises a percussive hammer and bit.

According to a preferred feature of the invention the lower end of the outer tube is formed as an annular cutting element.

The invention will be more fully understood in the light of the following description of several specific embodiments.

Brief Description of the Drawing

The description is made with reference to the accompanying drawing of which:

Figure 1 is a schematic sectional side elevation of a drilling arrangement according to the first embodiment;

Figure 2 is a schematic sectional side elevation of a drilling arrangement according to the second embodiment;

Figure 3 is a schematic sectional side elevation of a drilling arrangement according to the third embodiment with the drill bit in the inactive position;

Figure 4 is a schematic sectional side elevation of a drilling arrangement according to the third embodiment with the drill bit in the active position; and

Figure 5 is a schematic sectional side elevation of a drilling arrangement according to the fourth embodiment with the drill bit in the inactive position.

Detailed Description of Specific Embodiments

The first embodiment as shown in Figure 1 comprises a drilling arrangement which utilises a rotary blade bit in association with a casing. The first embodiment comprises an outer tube 11 which serves as a bore hole casing and which is threadably supports an annular support ring 13 which is of increased dimensions at its lower end. The support ring 13 in turn threadably supports an outer annular cutting bit 15 at its lower end. The outer casing 11 supports an annular seat member 23 which is clampingly received between the casing 11 and the support ring 13. The seat member 23 formed as an annular member which is abuttingly received between opposed shoulders of the casing and the support ring and a plurality of inwardly directed lugs 25 at equiangular spacings the seat members inner perimeter and which extend inwardly from the bore of the support ring 13 and casing 11.

The outer casing 11 is associated with an inner tube 17 which is concentrically received and supported within the casing 11. The inner tube is capable of relative axial movement within the casing which is independent of the casing. The lower end of the inner tube supports an annular drive sub 19 which in turn supports a rotary blade bit 21 of conventional form at its lower end. The inner portion of the drive sub 19 is tapered such that it is divergent from a position intermediate of its inner and outer ends to the inner end of the inner tube 17.

The drilling arrangement further comprises a sealing ring 29 which is located around the inner portion of drive sub 19 which in use is to be located inward of the seat member 23. The sealing ring 29 comprises a rigid support ring 31 which is proximate the seat member 23 and a resilient ring 33 which s remote from the support ring and which is formed of any suitable resiliently compressible material.

In use the inner and outer tube are introduced into the bore hole. When the drilling arrangement is active the inner tube is moved relative to the outer tube such that the drill bit 21 is inward of its outer most position relative to the outer tube and is located in the region of the annular cutting bit 15 as a result of the inner tube 17 being^' displaced inwardly with respect to the outer tube 11 which is due to the drill bit 21 being engaged with the bottom of the bore hole in association with the annular cutting element 15 of the casing 11. As a result the sealing ring 29 is loosely received in the annular space between divergent portion 27 of the drive sub 19 and the outer tube 11. As a result fluid is permitted to freely flow from the annular space between the inner and outer tubes 17 and 11 to the lower cutting faces of the drill bit 21 in order to carry cuttings to the inner passage way within the drive sub 19 in order to clear cuttings away from the drill bit and to carry the cuttings to the surface.

In addition the drive sub 19 is provided with a plurality of ports 35 which extend obliquely upward between the exterior and interior face of the drive sub to be convergent in a direction away from the drill bit 21. The presence of the ports 35 serves to enhance the flow of fluid and cuttings into the interior of the drive sub 19 from the drill bit 21.

On cessation of the drilling action, if the inner tube 17 is caused to move outwardly relative to the outer tube 11 , as a result of the action of the rotary bit 21 and/or by positive displacement between tubes, the sealing ring 29 is brought into abutting relationship with the seat 23 and with the opposed face of the divergent portion 27 of the drive sub 19. Because of the presence of the resilient annular member 33 the sealing ring 29 provides a sealing engagement between the exterior face of the divergent portion 27 and the internal face of the outer tube 11 to close fluid flow to the drill bit.

On completion of the drilling operation it is then possible to extract the inner tube 17 together with the drive sub 19 and rotary bit 21 from the bore hole. In so doing the drill bit will move past the annular seat member 23 and will engage with the sealing ring 29. As a result the entire space within the outer tube 11 can be vacated by the drill string and be available to be utilised for accommodating a conduit. If it is necessary to introduce a further material into the annular space between the outer tube 11 and the conduit this can be readily achieved. Once the conduit is in place the outer tube 11 can then be extracted from the bore hole.

In the case of the second embodiment as shown at Figure 2 the divergent portion

27 is reduced in its axial extent and the sealing ring 29 is slidably received over the non-divergent portion of the sealing ring 31 below the divergent portion. In addition the sealing ring is formed as a single integral element. The drilling arrangement of the second embodiment operates in the same manner as the first embodiment of Figure 1.

In the case of the third embodiment the drilling arrangement is associated with a reverse circulation percussive hammer (shown schematically at 40) which is driven from fluid which is to be delivered to the hammer from the space between the outer and inner tubes and is delivered through a cross-over sub 41. The delivery of fluid through the crossover-sub 41 is constant in order that the hammer can operate in its required manner independently of the axial relationship between the inner and outer tube. In the case of the third embodiment the hammer extends into the bore hole beyond the annular cutting bit 15 which is located at the end of the casing. In the case of the third embodiment the seat ring 23 is supported from the outer tube as in the case of the first and second embodiment and the sealing ring is received over the drill sub between the cross-over sub and the hammer to sealingly cooperate with the cross-over sub when the inner tube is displaced at its most outward position relative to the outer tube and when the hammer is active. As a result fluid from the space between the inner and outer tubes is delivered solely to the hammer through the cross-over sub 41. On withdrawal of the hammer into the outer tube and as shown at Figure 4 the sealing engagement of the sealing ring with crossover sub is lost and fluid can be delivered into the bore hole to facilitate clearance of the bore hole and if desired to maintain a pressure in the bore hole.

The fourth embodiment as shown at Figure 5 relates to an arrangement similar to the third embodiment with the exception that the drill bit is driven from a conventional percussive hammer (not shown) which utilises a second cross over sub 43 to effect the delivery of fluid into the hammer and the delivery of cuttings into the inner tube.

Throughout the specification, unless the context requires otherwise, the word "comprise" or variations such as "comprises" or "comprising", will be understood to imply the inclusion of a stated integer or group of integers but not the exclusion of any other integer or group of integers.

It should be appreciated that the scope of the present invention need not be limited to the particular scope of the embodiments describe above.

Claims

ClaimsThe claims defining the invention are as follows:

1. A drilling arrangement comprising an outer tube and inner tube which are intended to be received in a bore hole, the annular space between the tubes being adapted to be connected to a source of pressurised fluid, the inner tube being connected to an exhaust, a valve provided between the tubes to control fluid to flow into the bore hole whereby relative movement between the inner and outer tubes open and close the valve to enable the pressurised fluid to be delivered into the bore hole as desired.

2. A drilling arrangement as claimed at claim 1 wherein the inner tube is removable from within the outer tube and is adapted to engage the valve member and remove the valve member from the outer tube.

3. A drilling arrangement comprising an outer and inner tube, the lower end of the inner tube is intended to be provided with a drilling element, the annular space between the tubes being adapted to be connected to a source of pressurised fluid, the inner tube being connected to an exhaust of the drilling element, a valve provided between the tubes to control fluid to flow into the bore hole whereby relative movement between the inner and outer tubes open and close the valve to enable the pressurised fluid to be delivered into the bore hole as desired.

4. A drilling arrangement as claimed at claim 3 wherein the valve is open when the drilling element is active and the valve is closed when the drilling element is inactive.

5. A drilling arrangement as claimed at claims 3 or 4 wherein the pressurised fluid is delivered to the drilling element.

6. A drilling arrangement as claimed at any one of claims 3 to 4 wherein the drilling element comprises a rotary bit.

7. A drilling arrangement as claimed at claim 5 wherein the rotary bit comprises a blade bit.

8. A drilling arrangement as claimed at claim 5 wherein the rotary bit comprises a diamond bit.

9. A drilling arrangement as claimed at claim 5 wherein the rotary bit comprises a tricone bit.

10. A drilling arrangement as claimed at any one of claims 5 to 9 wherein the valve comprises an annular seat supported by one of the tubes, and an annular valve member supported between the inner and outer tubes and the seat whereby relative axial displacement between the tubes in one or the other direction will cause the sealing element to move into and out of sealing engagement with the tubes.

11. A drilling arrangement as claimed at claim 10 wherein the seat comprises an annular element formed with a plurality of angularly spaced lugs.

12. A drilling arrangement as claimed at claim 10 or 11 wherein the seat is supported from the inner face of the outer tube.

13. A drilling arrangement as claimed at claim 12 wherein the outer walls of the inner tube inward of the seat are divergent.

14. A drilling arrangement as claimed at claim 12 wherein the outer wall of the inner tube inward of the seat are parallel.

15. A drilling arrangement as claimed at any one of claims 10 to 14 wherein the inner tube is formed with at least one port extending between the inner and outer face, said at least one port being located outward of the valve.

16. A drilling arrangement as claimed at any one of claims 10 to 15 wherein the inner tube is removable from within the outer tube and is adapted to engage the valve member and remove the valve member from the outer tube.

17. A drilling arrangement as claimed at claim 3 wherein the valve is closed when the drilling element is active and the valve is open when the drilling element is inactive, said drilling element when active utilising pressurised fluid from the annular space which is bypassed past the valve, said pressurised fluid being delivered into the bore hole around the drilling element when the valve is open.

18. A drilling arrangement is claimed at claim 17 wherein the drilling element comprises a percussive hammer and bit.

19. A drilling arrangement as claimed at claim 18 wherein the valve comprises an annular seat supported by one of the tubes, and an annular valve member supported between the inner and outer tubes and the seat whereby relative axial displacement between the tubes in one or the other direction will cause the sealing element to move into and out of sealing engagement with the tubes.

20. A drilling arrangement as claimed at claim 19 wherein the seat comprises an annular element formed with a plurality of angularly spaced lugs.

21. A drilling arrangement as claimed at claim 19 to 20 wherein the seat is supported from the inner face of the outer tube.

22. A drilling arrangement as claimed at claim 21 wherein the outer wall of the inner tube inward of the seat are parallel.

23. A drilling arrangement as claimed at any one of claims 19 to 22 wherein the inner tube is formed with at least one port extending between the inner and outer face, said at least one port being located outward of the valve.

24. A drilling arrangement as claimed at any one of claims 19 to 23 wherein the inner tube is removable from within the outer tube and is adapted to engage the valve member and remove the valve member from the outer tube.

25. A drilling arrangement as claimed at any one of claims 3 to 24 wherein the lower end of the outer tube is formed as an annular cutting element.

26. A drilling arrangement comprising an outer tube and inner tube, the lower end of the inner tube is intended to be provided with a drilling element, the annular space between the tubes being adapted to be connected to a source of pressurised fluid, the interior of the inner tube being adapted to be connected to an exhaust, a valve provided between the tubes to control fluid to flow into the bore hole whereby relative movement between the inner and outer tubes open and close the valve, to enable fluid to flow to the drilling element when the drilling element is active or inactive and to at least reduce the fluid flow to the drilling element when the drilling element is inactive or active respectively.

27. A drilling arrangement as claimed at claim 26 wherein the valve comprises an annular seat supported by one of the tubes, and an annular valve member supported between the inner and outer tubes and the seat whereby relative axial displacement between the tubes in one or the other direction will cause the sealing element to move into and out of sealing engagement with the tubes.

28. A drilling arrangement as claimed at claim 27 wherein the seat comprises an annular element formed with a plurality of angularly spaced lugs.

29. A drilling arrangement as claimed at claim 27 or 28 wherein the seat is supported from the inner face of the outer tube.

30. A drilling arrangement as claimed at claim 29 wherein the outer walls of the inner tube inward of the seat are divergent.

31. A drilling arrangement as claimed at claim 29 wherein the outer wall of the inner tube inward of the seat are parallel.

32. A drilling arrangement as claimed at any one of claims 26 to 31 wherein the inner tube is formed with at least one port extending between the inner and outer face, said at least one port being located outward of the valve.

33. A drilling arrangement as claimed at any one of claims 26 to 31 wherein the drilling element comprises a rotary bit and the valve is open when the drilling element is active.

34. A drilling arrangement as claimed at claim 33 wherein the rotary bit comprises a blade bit.

35. A drilling arrangement as claimed at claim 33 wherein the rotary bit comprises a diamond bit.

36. A drilling arrangement as claimed at claim 33 wherein the rotary bit comprises a tricone bit.

37. A drilling arrangement as claimed at any one of claims 26 to 31 wherein the drilling element comprises a percussive hammer and bit and the valve is closed when the drilling element is inactive.

38. A drilling arrangement as claimed at any one of claims 27 to 37 wherein the inner tube is removable from within the outer tube and is adapted to engage the valve member and remove the valve member from the outer tube.

39. A drilling arrangement as claimed at any one of claims 26 to 38 wherein the lower end of the outer tube is formed as an annular cutting element.

40. A drilling arrangement substantially as herein described in relation to the accompanying drawings.