Drill bit and method for drilling holes for installing pipes underground - Patents.com

Abstract

Presented herein is a drill bit (1) including a pilot bit (2) and a reamer. The pilot bit (2) includes a body (3) and a drilling face (4). The drill bit (1) is arranged to provide a hole for placing a pipe in the ground. The reamer includes at least one wing (7) pivotally attached to the body (3) of the pilot bit (2) such that the wing (7) extends outside an outer circle of the body (3) of the pilot bit (2) when the wing (7) is rotated to a drilling position and does not extend outside an outer circle of the body (3) of the pilot bit (2) when the wing (7) is rotated to a forward rotated position from the drilling position.

Description

[Technical field]

[0001] [Background of the invention] DRILL BITS FIELD OF THEINVENTION This invention relates to drill bits, particularly for drilling holes for installing pipes in the earth. [Background technology]

[0002] The size of the hole to be drilled to install the pipe in the ground must be at least as large as the outer diameter of the pipe. WO2015059341A1 discloses a drilling rig comprising a pilot bit for drilling the center of the hole, a ring bit detachably connectable thereto and acting as an expander for drilling the outer circle of the hole, and a device for drawing a casing pipe into the hole during drilling.

[0003] A problem with the type of drilling rig mentioned in the above example is that when the drilling rig is pulled out of the wellbore and the casing pipe is left in the wellbore, a ring bit must also be left at the end of the casing pipe to drill the outer circle of the hole at the bottom of the wellbore.

[0004] For this reason, several different arrangements have been disclosed that utilize movable wings as a reamer. Such arrangements are shown, for example, in GB2465653A, US5934394A, US5975222A, and WO2005085581A1. There remains a need to provide a new drill bit and method for drilling holes for installing pipes in the ground.

[0005] [Brief Description of the Invention] It is therefore an object of the present invention to develop a drill bit and a method for the drilling of holes for installing pipes in the ground. The arrangement according to the invention is characterized by what is disclosed in the independent claims. Some embodiments of the invention are disclosed in the dependent claims.

[0006] Here, a drill bit is presented, which includes a pilot bit and a reamer. The pilot bit includes a body and a drilling face. The drill bit is arranged to provide a hole for installing a pipe in the ground. The reamer has at least one wing pivotally attached to the body of the pilot bit, which extends outside the outer circle of the pilot bit body when rotated to a drilling position and does not extend outside the outer circle of the pilot bit body when rotated forward from the drilling position. The drilling face of the pilot bit is also called a face area, and the wings have corresponding face areas. The wings can also be arranged to rotate forward and back again, which changes the angle between the face area of ​​the pilot bit and the face area of ​​the wings. With such an arrangement, a hole is effectively made in the pipe to be installed in the ground. Furthermore, the wings can be reliably arranged in a position where the drill bit can be completely removed from the inside of the pipe to be installed in the ground. Similarly, the area of ​​the outermost part of the wings can be significantly increased, so that the drilling surface of the wings of the outermost part of the drill bit is relatively large. The wings comprise at least one bracket and an outer portion, the outer portion of the wings being arranged to redirect the flow of the flushing medium, which also desirably controls the flow of the flushing medium. According to one embodiment, there are at least two wings as described above. The spacing between the wings can be fairly small, which provides good drilling properties. The wings can be of simple shape and are easy to manufacture.

[0007] A wing comprises at least one bracket and an outer portion. Such a wing may be of simple geometry. The wing may be rotated from the bracket. The outer portion may be formed to any desired size and shape. The outer portion may be wider than the bracket, for example.

[0008] According to one embodiment, the wings have an outer portion, at least on its outer surface, which is curved, the shape of the outer portion being such that a drill bit can function reliably.

[0009] According to one embodiment, the drilling face of the pilot bit includes flushing grooves. The wings can include outer portions, the flushing grooves arranged to convey the flushing medium toward the outer portions of the wings, which are arranged to redirect the flow of the flushing medium toward the rear portion of the drill bit. The flow of the flushing medium can then be controlled in a desired manner.

[0010] According to one embodiment, the wing comprises from the outer part towards the central part of the drill bit at least two brackets between which the flushing groove is arranged, so that the flow rate of the flushing medium can be controlled particularly precisely and reliably.

[0011] According to one embodiment, the drill bit includes a pivot pin in connection with each wing (to the body of the pilot bit) and arranged to rotate the wings about its central axis, this arrangement allows a simple mechanism and ensures rotation of the wings.

[0012] According to one embodiment, the central axis of the pivot pin is substantially perpendicular to the direction of the central axis of the drill bit. This arrangement also increases the reliability of the structure. In this context, "substantially perpendicular" refers to an angle between the direction of the central axis of the pivot pin and the central axis of the drill bit of 70° to 110°, preferably 80° to 100°.

[0013] According to one embodiment, the wing comprises at least two brackets, at the ends of which the pivot pins are arranged, such a wing has a favorable shape and ensures that the wing can swing.

[0014] According to one embodiment, the at least two brackets each include a separate pivot pin at their end, so that the two brackets are not pivoted by only one pivot pin and there is no need to drill a slot in the pilot bit for the pivot pin, thus making the body of the pilot bit more durable.

[0015] According to one embodiment, the wing includes a drilling surface, and the drilling surface of the pilot bit and the drilling surface of the wing have drilling buttons.

[0016] According to one embodiment, the body of the pilot bit includes a shoulder for the casing shoe of the pipe to be installed in the ground, so that the pipe to be installed in the ground can be pulled into the ground by the shoulder. Such an arrangement is simple and reliable for the installation of the pipe to be installed in the ground.

[0017] According to one embodiment, the wing is substantially perpendicular to the direction of the central axis of the drill bit when rotated to the drilling position. This type of construction is simple and reliable. In this context, "substantially perpendicular" means that when the wing is oriented in the drilling position, the angle between the direction of its face area and the central axis of the drill bit is between 70° and 110°, preferably between 80° and 100°.

[0018] According to one embodiment, the wings are rotated forward at least 30 degrees from a perpendicular direction to the direction of the central axis of the drill bit when rotated from the drilling position to the rotated forward position, This arrangement makes it easy and simple to remove the drill bit from inside the pipe installed in the ground.

[0019] According to one embodiment, the blank of the wing is formed by flame-cutting a sheet. The manufacturing of the wing is then easy and simple. The material loss is minimal. The wing can be made, for example, of wear-resistant steel. Furthermore, the wing can be made, for example, of engineering steel, from round bars or forged blanks.

[0020] According to one embodiment, a method for drilling a hole for installation of a pipe in the ground uses the drill bit presented herein. When drilling, the wings are rotated to a drilling position and extend outside the outer circle of the pilot bit body. When removing the drill bit from inside the pipe, the wings are rotated to a forward rotated position so that they do not extend outside the outer circle of the pilot bit body. This type of solution is simple and reliable.

[0021] The invention will now be described in more detail with reference to several embodiments and with reference to the accompanying drawings, in which: FIG. [Brief description of the drawings]

[0022] [Figure 1] FIG. 1 is a schematic front perspective view of a drill bit, the drill bit being in a drilling position. [Diagram 2] FIG. 2 is a schematic front perspective view of the drill bit of FIG. 1 in a position for removal from within the pipe. [Diagram 3] FIG. 3 is a schematic front view of the drill bit of FIG. [Figure 4] FIG. 4 is a schematic front perspective view of the drill bit of FIG. 1, with the pilot bit body shown in transparency. [Diagram 5] FIG. 5 is a schematic cross-sectional side view of the drill bit of FIG. 1, with the drill bit in a drilling position. [Figure 6] FIG. 6 is a schematic cross-sectional side view of the drill bit of FIG. 1 in a position where it can be removed from within the pipe. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0023] [Detailed Description of the Invention] 1 shows a drill bit 1 including a pilot bit 2. The pilot bit 2 includes a body 3 and a drilling face 4. The drill bit 1 further includes wings 7. The wings 7 function as a reamer for the drill bit 1 and are pivotally mounted to the body 3 of the pilot bit 2 for rotation.

[0024] When the wings 7 are rotated into a drilling position in the manner shown in Figure 1, the wings 7 extend outside the outer circle of the body 3 of the pilot bit 2. This is also shown in Figure 3. Each wing 7 includes a wing drilling surface 11. The pilot bit drilling surface 4 and the wing drilling surface 11 may include a drilling button 12. When drilling, the drill bit 1 is reciprocated and rotated. That is, the drill bit 1 is used for percussion drilling and rotary drilling. The drill bit 1 can be used to drill holes in the ground or in hard materials such as rock.

[0025] The body 3 of the pilot bit may include a shoulder 5. The shoulder 5 may be arranged against a casing shoe 6. The casing shoe 6 may be fixed to the lower end of the pipe to be placed in the ground. The shoulder 5 and the casing shoe 6 may then be used to place the pipe to be placed in the ground. For the sake of clarity, the pipe to be placed in the ground to which the casing shoe 6 is fixed is not shown in Figs. 1-4. Figs. 5 and 6 show the pipe 16 to be placed in the ground. The pipe to be placed in the ground may be either subsurface or permanently installed. Instead of using a shoulder and a casing shoe, the pipe 16 may be placed in the ground and may be pushed, driven and / or vibrated, for example, from the upper end of the pipe into the ground. The diameter of the pipe 16 to be placed in the ground may be, for example, between 100 mm and 1,000 mm.

[0026] The pilot bit 2 and wings 7 provide a hole for placing the pipe in the ground. In the drilling position, the wings 7 extend far outside the outer circle of the body 3 of the pilot bit 2 so that the hole provided is at least as large as the pipe to be placed in the ground.

[0027] By pushing the drill bit 1 in the drilling direction, the extensions of the drilling surface, i.e. the wings 7, rotate into the drilling position. When the drill bit 1 is lifted out of the hole, the wings 7 rotate into the position shown in FIG. 2. In this position, rotated forward from the drilling position, the wings do not extend outside the outer circle of the pilot bit body. When rotated forward, the wings 7 rotate in the drilling direction towards the bottom of the drilled hole. The drill bit 1 can then be withdrawn from inside the pipe installed in the ground. The wings 7 do not extend outside the outer circle of the body 3 of the pilot bit 2. In the embodiment of the figure, the wings 7 do not extend outside the circle defined by the inner diameter of the casing shoe 6 in this position. The circle around which the wings 7 do not extend outside may be generally smaller than the outer diameter of the body 3 of the pilot bit 2 relative to the width of the shoulder 5.

[0028] The wing 7 has at least one bracket 8 and an outer portion 9. The outer portion 9 can be, for example, wider than the bracket 8. The width of the outer portion 9 can be as large as possible, so that the drill bit 1 can also include as many drilling surfaces as possible on its outer circle. If the drill bit 1 also includes many drilling surfaces on its outer circle, it is also possible to provide as many drilling buttons 12 as possible on the outer circle. The width of the outer portion 9 can be, for example, such that the sum of the widths of the outer portions 9 is greater than the sum of the widths of the gaps between the outermost portions of the wings 7. The outer portion 9 can be curved at least on its outer surface.

[0029] The brackets 8 extend from the outer portion 9 towards a central portion of the pilot bit 2. For example, in the illustrated embodiment, the wing 7 includes two brackets 8 such that both of them extend towards the central portion of the pilot bit 2, but neither of them extends to the center point of the pilot bit, but slightly beyond it.

[0030] The wings 7 are pivotable from the bracket 8. In the body 3 of the pilot bit 2, the drill bit 1 may include a pivot pin 10 connected to each wing 7 and about a central axis about which the wings 7 are rotatably disposed. The pivot pins 10 may be disposed through the ends of the bracket 8. The pivot pins 10 may be locked to the body 3 of the pilot bit 2 by a locking ring, for example made of polyurethane. Additionally, the pivot pins may be locked in other ways, such as a locking pin or a mechanical stop that prevents the pivot pin from sliding off.

[0031] A wing 7 may include two or more brackets 8 and the wing 7 may be pivotally attached by one pivot pin 10 extending through all the brackets 8 in the manner shown in Fig. 4. Alternatively, the at least two brackets 8 may include respective individual pivot pins 10 at their ends, so that the two brackets 8 are not pivotally attached only by one pivot pin 10 and it is not necessary to drill a slot in the body 3 of the pilot bit 2 for the pivot pins 10.

[0032] The central axis of the pivot pin 10 can be substantially perpendicular to the central axial direction of the drill bit 1. The central axis of the pivot pin can then be perpendicular to the direction of the central axis of the drill bit 1 or can differ from the perpendicular direction by, for example, up to 20°, preferably up to 10°.

[0033] The drilling face 4 of the pilot bit 2 may include flushing grooves 13. A flushing medium, such as compressed air, may be fed towards the front of the drill bit 1 along a flushing channel 14, for example in the centre of the drill bit 1. The drill bit 1 may include the drilling face 4 of the pilot bit 2 at the end of the flushing channel 14, such that there is some body structure at the end of the flushing channel 14. Thus, the flushing medium does not flow at least completely in the drilling direction, i.e., axially of the drill bit 1 towards the ground being drilled, but rather the flow of the flushing medium is at least partially directed radially of the drill bit 1.

[0034] After the rinsing channel 14, at least a part of the flow of the flushing medium flows in flushing grooves 13 from the center of the drill bit 1 towards the outer edge of the drill bit. The rinsing grooves 13 direct the rinsing medium towards the outer parts 9 of the wings 7, which are arranged to direct the flow of the flushing medium towards the side grooves 15 towards the rear part of the drill bit 1. In this way, the flushing medium can flow upwards in a pipe installed in the ground, avoiding the flushing medium flowing into the ground.

[0035] In the embodiment shown, the wing 7 comprises at least two brackets 8 from the outer portion 9 towards the central portion of the drill bit 1. A flushing groove 13 is disposed between these brackets 8.

[0036] The outer parts 9 of the wings direct the flow of the flushing medium in the desired direction. For the flow of the flushing medium, the drilling face does not necessarily need flushing grooves. The flushing medium flows between the drilling face and the wings. The surface of the wing facing the drilling face can be provided with rinsing grooves for the flushing medium. On the other hand, the flushing medium can be arranged on both the drilling face and the wing surface, in which case only one or neither of them can contain flushing grooves.

[0037] If the wing comprises two brackets 8, the wing can be constructed such that the brackets 8 are connected to each other by the wing material over more than half the length of the bracket. Such a wing is more robust than a structure in which the brackets are not joined together until close to the outer portion 9 of the wing. If the brackets are connected to each other by the wing material over more than half the length of the bracket, the wing ensures a flow of the flushing medium. And it is also possible to provide a flushing groove for the flushing medium in the part of the wing where the brackets are joined together.

[0038] When rotated into the drilling position, the wings 7 can be substantially perpendicular to the direction of the central axis of the drill bit 1. The wings 7 can then be perpendicular to the direction of the central axis of the drill bit 1 when rotated into the drilling position, or can differ from the perpendicular direction by, for example, up to 20°, preferably up to 10°.

[0039] The wings 7 may be rotated forward at least 30° from a perpendicular direction to the direction of the central axis of the drill bit 1 when rotated from the drilling position to the rotated forward position. According to an embodiment, the wings 7 are rotated forward at least 45° from a perpendicular direction to the direction of the central axis of the drill bit 1 when rotated from the drilling position to the rotated forward position. The amount that the wings need to rotate in the forward direction depends on the size class and geometry of the bit and the amount of space available. Larger size classes require a smaller change in angle to provide a sufficient change in the outer diameter of the bit than smaller size classes. In the illustrated embodiment, the wings rotate 66°.

[0040] Preferably, the wings 7 rotate less than 90°. Then, when the drill bit 1 is pressed against the ground, the wings 7 can be rotated into the drilling position without the need for a separate actuator to move the wings 7. The actuator can then move the wings forwards and backwards. With respect to the drill bit 1, the structure is subjected to very high loads. Therefore, it is preferable to provide the drill bit 1 without an actuator to move the wings 7. Then, when the drill bit 1 is moved forward, this rotates the wings 7 into the drilling position, and when the drill bit 1 is moved backward, this rotates the wings 7 from the drilling position into a position where they rotate forwards.

[0041] The blanks for the wings 7 can be formed by frame cutting from a sheet. The wings can be made, for example, from wear-resistant steel. Furthermore, the wings can be made, for example, from engineering steel from round bars or forged blanks.

[0042] The drill bit 1 presented here can be used in a drilling method for installing a pipe in the ground. When drilling, the wings 7 are rotated to a drilling position and extend outside the outer circle of the body 3 of the pilot bit 2. When the drill bit 1 is removed from the pipe, the wings 7 are in a position directed forward from the drilling position so that the wings 7 do not extend outside the outer circle of the body 3 of the pilot bit 2. Preferably, the rotation of the wings 7 to the drilling position and from the drilling position to the position rotated forward is performed without an actuator by advancing and retracting the drill bit 1. The flow of the rinsing medium is rotated by the outer parts 9 of the wings.

[0043] It is obvious to a person skilled in the art that as technology advances, the basic idea of ​​the present invention can be implemented in various ways, therefore the present invention and its embodiments are not limited to the above examples, but can be modified in various ways within the scope of the claims.

Claims

1. A drill bit (1) including a pilot bit (2) including a body (3) and a drilling face (4), and a reamer, the drill bit being arranged to drill a hole for installing a pipe in the ground, The reamer includes at least one wing (7) rotatably pivoted to the body (3) of the pilot bit (2); The wings (7) extend outside the outer circle of the body (3) of the pilot bit (2) when rotated into a drilling position; When the wings (7) are rotated from the drilling position to a forward rotated position, they do not extend outside the outer circle of the body (3) of the pilot bit (2); The wing (7) comprises at least one bracket (8) and an outer portion (9); characterised in that the outer parts (9) of the wings (7) are arranged to redirect the flow of the flushing medium, Drill bit.

2. The reamer includes at least two wings (7) rotatably and pivotally mounted on the body (3) of the pilot bit (2); the wings (7) extend outside the outer circle of the body (3) of the pilot bit (2) when rotated to a drilling position, and the wings (7) do not extend outside the outer circle of the body (3) of the pilot bit (2) when rotated to a position rotated forward from the drilling position. The drill bit of claim 1.

3. said wing (7) having at least an outer portion (9) whose outer surface is curved, A drill bit according to claim 1 or 2.

4. A flushing groove (13) is provided on the drilling surface (4) of the pilot bit (2), The wing (7) includes an outer portion (9); The flushing groove (13) is arranged to convey the flushing medium towards the outer portion (9) of the wing (7); characterised in that the outer parts (9) of the wings are arranged to redirect the flow of flushing medium towards the rear part of the drill bit (1), A drill bit according to any one of claims 1 to 3.

5. characterised in that the wing (7) comprises at least two brackets (8) extending from the outer portion (9) towards the central portion of the drill bit (1) and between which flushing grooves (13) are arranged, The drill bit of claim 4.

6. The drill bit (1) is characterized in that it includes a pivot pin (10) connected to each wing (7) and arranged to rotate the wings (7) around its central axis. A drill bit according to any one of claims 1 to 5.

7. The central axis of the pivot pin (10) is substantially perpendicular to the direction of the central axis of the drill bit (1). The drill bit of claim 6.

8. The wing (7) comprises at least two brackets (8) at the ends of which pivot pins (10) are arranged. A drill bit according to claim 6 or 7.

9. The brackets (8) are connected to each other by wing material over more than half the length of the brackets, The drill bit of claim 8.

10. said at least two brackets (8) each including a respective pivot pin (10) at their end, A drill bit according to claim 8 or 9.

11. the wing (7) includes a drilling surface (11), characterized in that the drilling surface (4) of the pilot bit (2) and the drilling surface (11) of the wing (7) include a drilling button (12); A drill bit according to any one of the preceding claims.

12. a body (4) of the pilot bit (2) including a shoulder (5) for a casing shoe (6) of a pipe to be placed in the ground, the pipe to be placed in the ground being able to be pulled into the ground by the shoulder (5); A drill bit according to any one of the preceding claims.

13. the wings (7) being substantially perpendicular to the direction of the central axis of the drill bit (1) when rotated into the drilling position; A drill bit according to any one of the preceding claims.

14. the wing (7) is rotated forward at least 30° from a direction perpendicular to the direction of the central axis of the drill bit (1) when rotated from the drilling position to a position rotated forward from the drilling position; A drill bit according to any one of the preceding claims.

15. 15. A method for drilling a hole for a pipe to be placed in the ground using a drill bit (1) according to any one of claims 1 to 14, characterized in that when drilling, the wings (7) are turned to a drilling position so that they extend outside the outer circle of the body (3) of the pilot bit (2), and when removing the drill bit (1) from inside the pipe, the wings (7) are in a position turned forward from the drilling position such that the wings (7) do not extend outside the outer circle of the body (3) of the pilot bit (2).

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