DRILLING DEVICE

Abstract

The invention relates to a drilling device for hard rock using a fluid, having at least one drill head with a pre-chamber and a mixing chamber where at least one front-facing nozzle and at least one rear-facing nozzle are provided. The fluid is mixed with abrasives in the mixing chamber, and the fluid together with the abrasives exits from the front-facing nozzle or an opening. The fluid flow is separated in the region of the pre-chamber, abrasive-free fluid exits the rear-facing nozzles, abrasives and the abrasive-free fluid are mixed in the mixing chamber, and the fluid mixed with the abrasives exits from the front-pacing nozzle or an opening.

Claims

1-15. (canceled)

16. A drilling device for hard rock with a drilling fluid, the drilling device comprising a drill head for being positioned facing said hard rock, a pre chamber and a mixing chamber being arranged within said drilling head; at least one distal opening located in said drilling head at least one rear-facing nozzle provided in said drilling head wherein said pre chamber is connected to said mixing chamber by a first supply line; wherein a second supply line is connected to said pre chamber for delivering an abrasive-free fluid wherein a third supply line is connected to said mixing chamber for delivering an abrasive stream; wherein said mixing chamber mixes said abrasive stream and said abrasive-free fluid to obtain said drilling fluid; wherein said at least one distal opening is arranged downstream the mixing chamber; and wherein said at least one rear-facing nozzle is arranged such that the drilling fluid delivered by said at least one distal opening is repelled by said hard rock being discharged by abrasive-free fluid from said at least one rear-facing nozzle.

17. The drilling device according to claim 16, wherein the pre chamber and the mixing chamber are arranged spatially separated from each other in the drill head.

18. The drilling device according to claim 16, wherein said abrasive-free supply line and said abrasive supply line run inside the drilling device.

19. The drilling device according to claim 16, wherein said at least one abrasive-free supply line runs coaxially to an axis of the drill head.

20. The drilling device according to claim 16, wherein the abrasives reaching the mixing chamber via the abrasive supply line are received from a borehole using a guide plate arranged on the outside of said drill head.

21. The drilling device according to claim 16, wherein the mixing chamber is embodied together with said at least one opening to define an open mixing chamber facing said hard rock.

22. The drilling device according to claim 16, wherein the drill head runs at least partially conical in a direction of said opening.

23. The drilling device according to claim 16, wherein the abrasives reaching the mixing chamber via the abrasive supply line are received from a borehole using a guide plate arranged on the outside of said drill head, the mixing chamber is embodied together with said at least one opening to define an open mixing chamber facing said hard rock, and the abrasives from the borehole reach the open mixing chamber via said abrasive supply line, wherein said abrasive supply line is radially oriented in said drill head.

24. The drilling device according to claim 16, wherein the rear-facing nozzles are arranged obliquely to a longitudinal center axis of the drill head.

25. The drilling device according to claim 16, wherein the drill head comprises a rotating inner part.

26. The drilling device according to claim 25, wherein the rotating inner part comprises at least one focusing nozzle, and wherein the rotating inner part comprises at least one transition line providing a connection from said abrasive supply line to said mixing chamber.

27. The drilling device according to claim 25, wherein an annular gap is radially provided between a receiving part of the drill head and the rotating inner part.

28. The drilling device according to claim 27, wherein the annular gap has a projected area being larger than a hydraulically effective area of the said annular gap, and wherein said rotating inner part of said drill head and said abrasive-free fluid provide a hydrodynamical bearing within said annular gap.

29. The drilling device according to claim 25, wherein at least one of a metal strips and a strand-like solid is guided into the drill head via said abrasive supply line, and wherein the abrasives are produced by the rotating inner part thus cutting said at least one of said metal strips and said stand-like solid into abrasive debris.

30. Use of the drilling device according to claim 16 for employing a site selected from a group comprising geothermal reservoirs, oil reservoirs, gas reservoirs, anchor boreholes, exploration boreholes, stimulation boreholes, boreholes for CT drilling and combinations thereof.

31. A drilling device for hard rock with a drilling fluid, the drilling device comprising a drill head for being positioned facing said hard rock, the drill head having a longitudinal axis, a pre chamber and a mixing chamber being arranged within said drill head; at least one distal opening located in said drill head; and at least one rear-facing flushing outlet provided in said drill head; wherein said pre chamber is connected to said mixing chamber by a first supply line; wherein a second supply line is connected to said pre chamber for delivering an abrasive-free fluid; wherein a third supply line is connected to said mixing chamber for delivering an abrasive stream; wherein said mixing chamber mixes said abrasive stream and said abrasive-free fluid to obtain said drilling fluid; wherein said at least one distal opening is arranged downstream the mixing chamber; and wherein said at least one rear-facing flushing outlet traverses the drill head in a direction transverse to said longitudinal axis, wherein the at least one rear-facing flushing outlet is connected to one of said second supply line and said pre chamber, such that the drilling fluid delivered by said at least one distal opening and repelled by said hard rock is lead away by abrasive-free fluid discharged from said at least one rear-facing flushing outlet.

32. A drilling device for hard rock with a drilling fluid, the drilling device comprising a drill head for being positioned facing said hard rock, a pre chamber and a mixing chamber being arranged within said drill head; at least one distal opening located in said drill head; and at least one rear-facing flushing outlet provided in said drill head; wherein said pre chamber is connected to said mixing chamber by a first supply line; wherein a second supply line is connected to said pre chamber for delivering an abrasive-free fluid; wherein a third supply line is connected to said mixing chamber for delivering an abrasive stream; wherein said mixing chamber mixes said abrasive stream and said abrasive-free fluid to obtain said drilling fluid; wherein said at least one distal opening is arranged downstream the mixing chamber; and wherein said at least one rear-facing flushing outlet is arranged radially to the said pre chamber, such that the drilling fluid delivered by said at least one distal opening and repelled by said hard rock is lead away by abrasive-free fluid discharged from said at least one rear-facing flushing outlet.

33. The drilling device according to claim 32, wherein said at least one distal opening is selected from the group comprising an opening, a plurality of openings, a nozzle, a plurality of nozzles, a channel and a plurality of channels.

34. The drilling device according to claim 32, wherein said at least one distal opening is oriented with an acute angle with respect to an axis of said drilling head.

35. The drilling device according to claim 32, wherein said drill head includes a rotatable inner part, wherein said rotatable inner part is radially supported within said drill head, wherein the rotatable inner part is arranged downstream said pre chamber, and wherein the rotatable inner part includes a fluid supply line rotating around a rotational axis of said rotatable part.

Description

[0030] The invention is described again in detail using the following figures:

[0031] FIG. 1 shows a simplified principle of the inventive drilling device 1 for hard rock in a vertical cross section of the drill head 2. Inside the drill head 2 runs a supply line 6a for the supply of abrasive-free fluid into the pre-chamber 8 and a supply line 6b for the supply of abrasives 5 (not shown) into a mixing chamber 3. Pre-chamber 8 and mixing chamber 3 are separated and arranged one behind the other in the direction towards the front-facing nozzle 4, so that the abrasive-free fluid enters the mixing chamber 3 via the pre-chamber 8 and a focusing nozzle 14 and can be mixed there with the abrasives 5 (not shown). The abrasive-free fluid is discharged from the drill head 2 into a borehole via a rear-facing nozzle 7. The rear-facing nozzle 7 is arranged at an angle to the central longitudinal axis of the drill head 2 and allows the use of the abrasive-free fluid as a propulsion agent and/or lubricant for the drilling device 1. On the other hand, the abrasive-containing fluid with the abrasive-free fluid serves as a cutting jet, which can continuously exit from the front-facing nozzle 4 of the drill head 2, whereby the abrasive-free fluid from the pre-chamber 8 enters the mixing chamber 3 via a focusing nozzle 14.

[0032] FIG. 2 shows a drilling device 1 according to the invention with a rotating inner part 9 in a vertical cross section. The drilling head 2 contains the housing of the drilling head 2, which comprises a static area of the housing as stator 11 and a rotating inner part 9. One recognizes the abrasive-free supply line 6a through which a fluid can enter the pre-chamber 8 of the drilling head 2. A rear-facing nozzle 7 is arranged obliquely to the longitudinal center axis from the pre-chamber 8, by means of which abrasive-free fluid can exit into the borehole. Via a transition line 12, abrasive-containing fluid passes from an abrasive-containing supply line 6b into the mixing chamber 3, in which the abrasive-free fluid is mixed with abrasive 5 (not shown). The rotating inner part 9 has a focusing nozzle 14 pointing towards the pre-chamber 8 or holes 13 of the static area of the drill head 2. This design arrangement of the holes 13, transition line 12 and focusing nozzle 14 is shown in the sectional views A-A and B-B.

[0033] The inner part 9 is spaced from the housing of the drill head 2 by an annular gap 10. As the inner part 9 rotates, part of the holes 13 of the pre-chamber 8 overlap with part of the focusing nozzle 14 of the rotating inner part. If the holes 13 of the pre-chamber 8 are congruent with the focusing nozzle 14, abrasive-free fluid enters the mixing chamber 3. The fluid mixed with the abrasives can then exit from the drill head 2 via the front-facing nozzle 4 and act as a cutting jet. The rotation of the inner part 9 is produced by the continuous application of abrasive-free fluid to at least one existing focusing nozzle 14, which is not congruent with the hole 13 of the static part of the drill head 2 with the abrasive-free fluid, the position of the focusing nozzle 14 forming an acute angle with respect to the drill head 2 of the inner part 9.

[0034] FIG. 3 shows a design embodiment of the drilling device 1 with an analogous structure to FIG. 2. Abrasive-free fluid is fed via an abrasive-free supply line 6a to the pre-chamber 8, which is partly located in the rotating inner part 9. The rear-facing nozzles 7 are arranged in the rotating inner part 9 at the pre-chamber 8. The rotating inner part 9 consists of two parts pressed into one another, wherein via an abrasive-containing supply line 6b a supply of abrasives 5 (not shown) into the mixing chamber 3 is made possible, which is arranged in the rotating inner part 9. A special feature of this embodiment is the branch of the abrasive-free fluid at the supply line 6a. The lubricating gap 15, at which a rotary movement of the rotating inner part 9 relative to the housing of the drill head 2 occurs, is acted upon with abrasive-free fluid. Since the pressure of the non-abrasive fluid is considerably higher than that of the fluid containing the abrasive, the non-abrasive fluid flows through the lubricating gap 15 and prevents the penetration of the abrasive 5 (not shown) into lubricating gap 15.

[0035] While the high pressures of the abrasive-free fluid generate a force in the rotating inner part 9, depending on the design, but especially in this design, which axially push out the rotating part 9, a pressure is built up in the annular gap 10 which generates an axial force which counteracts this. The annular gap 10 is designed so that the projected area of the annular gap 10 is larger than the hydraulically effective area, which would cause the rotating inner part 9 to be pushed out of the drill head 2. The supply of abrasive-free fluid to this annular surface of the annular gap 10 takes place through a line 17, in which a pressure drop is generated depending on the flow. If the rotating inner part were to be in contact with the cone, no fluid would be able to flow and no pressure would drop in line 17. The force is now greater due to the larger area of the annular gap 10 and presses the rotating inner part 9 into the drill head. Thus, fluid can flow by opening the annular gap 10, the pressure drop of the line 17 rises with flowing fluid, until a force and pressure equilibrium is achieved, which centers the rotating inner part 9 axially and forms an axial slide bearing. The fluid enabling this centering can exit from the flushing outlets 16 of the drilling device 1.

[0036] FIG. 4 shows a variation of FIG. 2 with the abrasive supply line 6b in the middle of the drilling device 1 through the pre-chamber 8. The drill holes 13 for generating pulsation are arranged around this supply line 6b by an overlap as described in FIG. 2. The rear-facing nozzles 7 are arranged in the static part of the drill head 2. The central supply allows the supply of a strand-like abrasive, which is crushed by the rotation of the rotating inner part 9 in the mixing chamber 3.

[0037] FIG. 5 shows a further particular configuration of the object of the invention in a vertical cross section. In this special embodiment of the drilling device 1, the mixing chamber 3 is designed as an open mixing chamber 19, i.e. it is located at the tip of the drilling head 2 and is often open or has an opening 20 in the direction of the rock, sediment or material to be impacted by the abrasive fluid. It can be seen that the drilling device 1 has a rotating inner part 9. The rotating inner part 9 has a focusing nozzle 14 pointing towards the rotating inner part 9 and/or the open mixing chamber 19. The drill head 2 contains the housing of the drill head 2 with a static area of the housing as stator 11 and a rotating inner part 9. An abrasive-free fluid is introduced into the pre-chamber 8 of the drill head 2 via the abrasive-free supply line 6a. From the pre-chamber 8, a rear-facing nozzle 7 is arranged obliquely to the longitudinal center axis, by means of which abrasive-free fluid can exit into the borehole. The abrasive-free fluid is fed into the open mixing chamber 19 via the front-facing nozzle, which is designed as focusing nozzle 14 here. The abrasive fluid in the open mixing chamber 19 is mixed with the non-abrasive fluid via an external supply line 6b, whereby the abrasive fluid mixed with the non-abrasive fluid can subsequently exit from the open mixing chamber 19 in the direction of the rock, sediment or material to be removed from the opening 20. The outer lateral boundaries of the tip of the drill head 2 are conical in the direction of opening 20 of the open mixing chamber 19, thus allowing the abrasive fluid to focus on the rock, sediment or material to be removed. In addition, it is possible (not shown) to lead abrasive fluid from the borehole via the external supply line 6b and/or another supply line into the open mixing chamber 19, analogous to the comments on FIG. 6.

[0038] FIG. 6 shows an additional possible embodiment of the object of the invention in a vertical sectional drawing. In this case, an abrasive-containing fluid passes from a supply line 6b arranged externally to the drill head 2 and containing abrasive into the open mixing chamber 19, whereby the abrasive-containing fluid is mixed with abrasives 5 from the borehole (not shown). It is also provided in order to ensure a continuous and/or constant supply of the abrasives 5 from the borehole via the supply line 6b into the open mixing chamber 19, a guide plate 18 is arranged on the outside of the drill head 2, which guides the abrasive materials 5 in the direction of the supply line 6b and ensures that the abrasives 5 from the borehole are mixed continuously and/or constantly with the abrasive-free fluid before they leave the opening 20.

REFERENCE SIGN LIST

[0039] 1 Drilling device [0040] 2 Drill head [0041] 3 Mixing chamber [0042] 4 Front-facing nozzle [0043] 5 Abrasives [0044] 6a Abrasive-free supply line [0045] 6b Abrasive supply line [0046] 7 Rear-facing nozzle [0047] 8 Pre-chamber [0048] 9 Rotating inner part [0049] 10 Annular gap [0050] 11 Stator [0051] 12 Transition line [0052] 13 Bore [0053] 14 Focusing nozzle [0054] 15 Lubrication gap [0055] 16 Flushing outlet [0056] 17 Line [0057] 18 Guide plate [0058] 19 Open mixing chamber [0059] 20 Opening