Composite drill bit capable of changing rock cutting modes without pulling out of hole

Abstract

The invention relates to a composite drill bit capable of changing a rock cutting mode without pulling out of a hole, which belongs to a drilling exploration tool and comprises a drill bit base body and a centralizing edge arranged on the periphery of the drill bit base body and integrated with the drill bit base body, the centralizing edge is formed by alternately arranging a fixed drill bit mounting seat and convex edges, and the length of the fixed drill bit mounting seat is greater than that of the lower edge of the drill bit base body; a cavity is formed in the lower portion of the drill bit base body. A movable seat is mounted in the cavity, movable drill bit mounting seats are fixed below the movable seat, a moving channel is formed between the movable drill bit mounting seats and below the movable seat, a flow guide pipe is arranged in the drilling tool connector and penetrates through the cavity and the movable seat, the lower end of the flow guide pipe is arranged in the moving channel, and a plurality of flow guide holes are formed in the periphery of the outer wall of the lower middle section of the flow guide pipe. According to the device, the drill bit can be rapidly replaced under the condition of not pulling out a hole, the device is suitable for a stratum structure where heterogeneous rocks (conglomerate rocks) and homogeneous rocks frequently and alternately occur, the non-working time occupied by pulling out the hole and replacing the drill bit is shortened, the drilling cost is reduced, the labor intensity of workers is reduced, and the drilling efficiency is improved.

Description

Technical Field

[0001] The invention belongs to drilling exploration tools, and mainly relates to a composite drill bit which can change the rock cutting mode without drilling. Background Art

[0002] At present, the full-drilling drill bits used in the field of oil and gas drilling (relative to coring drill bits, excluding coring drill bits) include: PDC drill bits, roller bits and composite drill bits of PDC drill bits + roller bits. These drill bits have a single rock breaking method and are solid and cannot be changed, and are suitable for rocks of different properties. When drilling into strata with different rock properties, under the existing technical conditions, it is necessary to promptly replace the corresponding drill bit. However, replacing the drill bit increases non-production time, increases drilling costs, affects rock breaking efficiency, and increases the labor intensity of workers. For interlayers where conglomerate and homogeneous rock frequently appear, if the drill bit is not replaced, using PDC drill bits, roller bits or composite drill bits of PDC drill bits + roller bits, the advantages of each drill bit for different rocks will not be brought into play, and the drill teeth may even fall off due to grinding, reducing the working life of the drill bit. Therefore, there is an urgent need for a drill bit that can be used for interlayers where heterogeneous rocks (conglomerate) and homogeneous rocks frequently appear. When different rocks appear, a composite drill bit can quickly change the rock cutting method (drill bit) according to instructions without starting drilling. Summary of the invention

[0003] The invention aims to overcome the shortcomings of the prior art and provides a composite drill bit which can change the rock cutting mode without drilling.

[0004] The composite drill bit of the present invention can change the rock cutting mode without drilling, comprises a drill bit base body, and a straightening edge axially arranged on the circumference of the drill bit base body and fixed thereto as a whole, the straightening edge being composed of more than two fixed drill bit mounting seats and more than two convex edges arranged alternately, the length of the fixed drill bit mounting seat being greater than the lower edge of the drill bit base body; the upper part of the drill bit base body is a drill tool connector, and the interior of the lower part thereof is a cavity; a movable seat is installed in the cavity, and more than two longitudinal movable drill bit mounting seats are evenly fixed below the movable seat and correspond to the positions of the convex edges, a movable channel is formed between the movable drill bit mounting seats and below the movable seat, a guide pipe is provided in the drill tool connector to pass through the cavity and the movable seat, and its lower end is placed in the movable channel, and a plurality of guide holes are evenly provided on the outer wall circumference of the middle and lower sections of the guide pipe.

[0005] As a further improvement of the present invention, one or more limiting holes are provided at the lower end of the convex ridge, a hanging sleeve is installed on the inner circumference of the cavity, a fixing hole is provided on the outer wall of the hanging sleeve to match the limiting hole and fixed with bolts, and the hanging sleeve is used to limit the downward movement of the movable seat.

[0006] As a further improvement of the present invention, a drill bit is installed at the lower end of the movable drill bit mounting seat.

[0007] As a further improvement of the present invention, each movable drill bit mounting seat is provided with a longitudinal guide groove, which passes through the movable seat and the guide hole to form a fluid channel, and the lower end of the guide groove is connected to the nozzle.

[0008] As a further improvement of the present invention, at least one mounting hole is provided at the upper end of the convex ridge, a horizontal axis is installed in the mounting hole, and the front end of the horizontal axis is placed in the pit on the outer wall of the guide tube, and a spring and a slider are sequentially mounted on the horizontal axis.

[0009] As a further improvement of the present invention, a PDC drill bit is installed at the bottom end of the fixed drill bit mounting seat, a roller drill bit is installed at the bottom end of the movable drill bit mounting seat, and a top block consistent with the direction of each of the above-mentioned sliders is fixed at the center position of the upper end of the movable seat. The top block is a U-shaped structure, and the U-shaped groove I therein is used in conjunction with the horizontal axis, and the inner side of the top block contacts the outer wall of the guide tube, so that the guide hole, U-shaped groove I, and the guide groove form a fluid channel.

[0010] As a further improvement of the present invention, a roller drill bit is installed at the bottom end of the fixed drill bit mounting seat, a PDC drill bit is installed at the bottom end of the movable drill bit mounting seat, and a top block consistent with the direction of each of the above-mentioned sliders is fixed at the upper end of the movable seat, close to the inner wall of the cavity. The top block is a U-shaped structure, and the U-shaped groove III therein is used in conjunction with the horizontal axis.

[0011] As a further improvement of the present invention, the height of the top block is greater than or equal to the height of all the sliders stacked together, and the width of the top block is less than the width of the sliders.

[0012] The composite drill bit of the present invention can change the rock cutting mode without starting to drill, has a reasonable structural design, can realize three drilling modes, and can quickly replace the drill bit without starting to drill. It is suitable for formation structures where heterogeneous rock (conglomerate) and homogeneous rock frequently alternate, reduces the non-working time occupied by starting to drill and replacing the drill bit, reduces the drilling cost, reduces the labor intensity of the staff, improves the drilling efficiency, and does not cause the drill bit to grind off the drill teeth and reduce the working life of the drill bit. BRIEF DESCRIPTION OF THE DRAWINGS

[0013] Figures 1-2 This is a schematic diagram of the liftable structure of the roller drill bit of the present invention; Figures 3-4 This is a schematic diagram of the liftable structure of the PDC drill bit of the present invention; Figure 5 to Figure 7 It is a cross-sectional view of different working states of embodiment 1 of the present invention; Figure 8 to Figure 10It is a cross-sectional view of different working states of embodiment 3 of the present invention. DETAILED DESCRIPTION

[0014] Example 1

[0015] The composite drill bit of the present invention can change the rock cutting mode without drilling, and comprises a drill bit base body 1, and a straightening edge axially arranged on the circumference of the drill bit base body 1 and fixed thereto as a whole, wherein the straightening edge is composed of two fixed drill bit mounting seats 2 and two convex edges 3 arranged alternately, that is, the fixed drill bit mounting seats 2 are symmetrically installed, the convex edges 3 are symmetrically installed, and the length of the fixed drill bit mounting seats 2 is greater than the lower edge of the drill bit base body 1, and PDC drill bits 18 are installed at the bottom ends of the two fixed drill bit mounting seats 2; Figure 1 ,like Figure 2 shown.

[0016] like Figure 1 As shown, the upper part of the drill bit base 1 is a drill tool connector 4, and the interior of the lower part is a cavity 5. A guide tube 8 is provided in the drill tool connector 4, and its lower end is placed in the cavity 5 and its bottom end is blocked and located at the same height as the edge of the convex ridge 3. A plurality of guide holes 9 are evenly arranged around the outer wall of the middle and lower sections of the guide tube 8.

[0017] like Figure 1 As shown, a movable seat 14 is installed in the cavity 5, and the movable seat 14 is matched with the inner wall of the cavity 5 and blocks it. The movable seat 14 and the inner wall of the cavity 5 are multi-faceted, so that the movable seat 14 can move up and down, but cannot rotate horizontally. Two longitudinal movable drill bit mounting seats 6 are symmetrically fixed below the movable seat 14 and are consistent with the direction of the above-mentioned convex edge 3. A movable channel 7 is formed between the two movable drill bit mounting seats 6 and below the movable seat 14. A guide tube 8 is provided in the drilling tool connector 4 to pass through the cavity 5 and the movable seat 14, and its lower end is placed in the movable channel 7; the movable seat 14 and the guide tube 8 are matched with each other in a clearance, so that the movable seat 14 can move up and down; a longitudinal guide groove 17 is provided in the movable drill bit mounting seat 6, and the guide groove 17 passes through the movable seat 14 and the guide hole 9 to form a fluid channel, and its lower end is connected to the nozzle; In this embodiment, two convex ribs 3 and two movable drill bit mounting seats 6 are provided; in other embodiments, three convex ribs 3 and three movable drill bit mounting seats 6 may be provided.

[0018] like Figure 1 As shown, three longitudinally arranged limit holes are provided at the lower end of the convex rib 3, and a hanging sleeve 15 is installed on the inner circumference of the cavity 5. The hanging sleeve 15 is sleeved on the outer side of each movable drill bit mounting seat 6, and a fixing hole is provided on the outer wall of the hanging sleeve 15 to match the limit hole and is fixed with a bolt 20. The hanging sleeve 15 is used to limit the downward movement of the movable seat 14, so that the movable seat 14 can move up and down in the cavity 5 without being separated from its main body.

[0019] like Figure 1 As shown, two longitudinally arranged mounting holes 10 are provided at the upper end of the convex rib 3, a transverse axis 11 is installed in each of the two mounting holes 10, and the front end of the transverse axis 11 is placed in the pit on the outer wall of the guide tube 8, a spring 12 and a slider 13 are sequentially mounted on the transverse axis 11, and the outer end surface of the slider 13 is provided with a groove, one end of the spring 12 is placed in the groove and fixedly connected thereto, and the other end is placed in the mounting hole; two symmetrical top blocks 19 are fixed at the upper center position of the movable seat 14, and the top block 19 and the slider 13 are symmetrical. The top block 19 is a U-shaped structure, and the U-shaped groove I therein cooperates with the horizontal axis 11, and the U-shaped groove I is connected with the guide groove 17. At this time, the inner side of the top block 19 contacts the outer wall of the guide tube 8, so that the guide hole 9, the U-shaped groove I, and the guide groove 17 form a fluid channel, and the drilling fluid is sprayed out through the guide hole 9, the U-shaped groove I, and the guide groove 17 through the nozzle; the height of the top block 19 is greater than or equal to the height of all the sliders 13 stacked together, the width of the top block 19 is less than the width of the slider 13, and the length of the top block 19 is equal to the length of the slider 13; In the above-mentioned slider, a positioning boss is provided at the inner bottom end of the upper slider 13, a pit I corresponding to the positioning boss is provided at the inner upper end of the lower slider 13, and a pit II corresponding to the positioning boss is provided on the inner side of the top end of the top block 19, and the positioning boss and pits I and II are all inclined surfaces.

[0020] like Figure 1 As shown, a roller drill bit 16 is installed at the bottom end of the movable drill bit mounting seat 6, and the two roller drill bits 16 are located below the convex rib 3, so that the roller drill bits 16 and the PDC drill bits 18 are arranged alternately, and the outer diameter of the roller drill bit 16 is the same as the outer edge of the convex rib 3. At the same time, the mounting hole 10, the limit hole, and the roller drill bit 16 on the convex rib 3 are provided with gauge teeth.

[0021] This device is not in use. Figure 1 As shown, when the spring 12 is fully extended, the top block 19 is placed under the slider 13: (1) When drilling with a roller drill bit 16 is required, such as Figure 5As shown, first, the drilling connector 4 is used to connect with the drilling tool, and then the drill bit is lowered into the well. When the drill bit is close to the bottom of the well, the drilling fluid is circulated first. The drilling fluid is sprayed out from the nozzle through the guide pipe 8, the groove in the top block 19, and the guide groove 17. After the bottom of the well is cleaned, the circulation of the drilling fluid is stopped, and the drill bit is lowered to the bottom of the well without rotating, and the circulation of the drilling fluid is started. In this process, the two layers of sliders 13 are in the original position under the action of the spring 12, and completely occupy the central space of the cavity 5. At this time, the upper end of the top block 19 is against the bottom end of the lower slider 13, and the positioning boss at the bottom end of the upper slider 13 is stuck in the pit I at the upper end of the lower slider 13, and the positioning boss at the bottom end of the lower slider 13 is stuck in the pit II at the upper end of the top block 19. At this time, the roller drill bit 16 is at the lowest position, and the roller drill bit 16 can be used for drilling; (2) When it is necessary to switch the roller bit 16 and the PDC bit 18 to drill synchronously, such as Figure 6 As shown, the drilling fluid is first circulated with half the maximum displacement to clean the bottom of the well, and then the drill bit is lowered to the bottom of the well to start rotary drilling. During this process, the slider 13 of the lower layer is thrown to the outermost edge by the centrifugal force (greater than the compression force of the spring 12) to contact the inner wall of the cavity 5, leaving the center position of the cavity 5, so that the top block 19 can slide upward and hit the bottom end of the upper slider 13, so that the positioning boss at the bottom end of the upper slider 13 is stuck in the pit II at the upper end of the top block 19. At this time, the lower horizontal axis 11 is placed in the U-shaped groove I in the top block 19, and the lower slider 13 is placed outside the top block 19. At this time, the bottom ends of the roller bit 16 and the PDC drill bit 18 are completely in the same horizontal position, so the roller bit 16 and the PDC drill bit 18 can be used to drill synchronously; (3) When it is necessary to switch the PDC drill bit 18 for drilling, Figure 7 As shown, the drilling fluid is first circulated with the maximum displacement to clean the bottom of the well, and then the drill bit is lowered to the bottom of the well to start rotary drilling. During this process, the upper and lower sliders 13 are thrown to the outermost edge and contact the inner wall of the cavity 5 under the action of centrifugal force (greater than the compression force of the spring 12), leaving the center position of the cavity 5, so that the top block 19 can slide upward to the top. At this time, the PDC drill bit 18 is at the lowest position, and the PDC drill bit 18 can be used for drilling.

[0022] Example 2

[0023] The composite drill bit of the present invention can change the rock cutting mode without drilling, and a circular top block 19 is provided at the upper end of the movable seat 14 and the outer wall of the guide tube 8, and two symmetrical U-shaped grooves II are opened on the top block 19, and the U-shaped grooves II are in the same direction as the slider 13, are used in conjunction with the horizontal axis 11, and are connected with the guide groove 17; other specific structures and working methods are the same as those in Example 1.

[0024] Example 3

[0025] The composite drill bit of the present invention can change the rock cutting mode without drilling. Figure 3 As shown in Figure 4, a roller drill bit 16 is installed at the bottom end of the two fixed drill bit mounting seats 2, and a PDC drill bit 18 is installed at the bottom end of the movable drill bit mounting seat 6. Two symmetrical fixed top blocks 19 are provided on the movable seat 14. The top blocks 19 are close to the inner wall of the cavity 5 and are in the same direction as the slider 13. A U-shaped groove III is provided in each of the top blocks, and the U-shaped groove III is used in conjunction with the horizontal axis. At this time, the guide hole 9, the cavity 5, and the guide groove 17 form a fluid channel; In this structure, a positioning boss is provided at the outer bottom end of the upper slider 13, a pit I corresponding to the positioning boss is provided at the outer upper end of the lower slider 13, and a pit II corresponding to the positioning boss is provided at the outer top of the top block 19, and the positioning boss and the pit I and pit II are all inclined surfaces; The other structures are the same as those in Example 1.

[0026] The device is not in use. Figure 3 As shown, when the spring 12 is fully extended, the top block 19 is placed below the horizontal side of the slider 13; (1) When it is necessary to switch the roller drill bit 16 for drilling, Figure 8 As shown, when the drill bit approaches the bottom of the well, the drilling fluid is circulated first, and after the bottom of the well is cleaned, the circulation of the drilling fluid is stopped, and the drill bit is lowered to the bottom of the well without rotating, and the drilling fluid is circulated again. During this process, the upper and lower sliders 13 are in their original positions under the action of the spring 12, and completely occupy the central space of the cavity 5. The drill string is lowered to make the drill bit touch the bottom of the well, so that the top block 19 can slide to the top of the cavity 5, and completely occupy the outer space of the cavity 5. The upper and lower sliders 13 will not be thrown out. At this time, the roller drill bit 16 is at the lowest position, and the roller drill bit 16 can be used for drilling; (2) When it is necessary to switch the roller bit 16 and the PDC bit 18 to drill synchronously, such as Fig. 9 As shown, when the drill bit contacts the bottom of the well, the drilling fluid is circulated with half of the maximum displacement to clean the bottom of the well, and then the drill bit is lowered to the bottom of the well to start rotary drilling. During this process, the upper slider 13 is thrown to the outermost edge under the action of centrifugal force (greater than the compression force of the spring 12) to contact the inner wall of the cavity 5, so that the top block 19 can slide to the position of the upper slider 13, and the positioning boss at the lower end of the upper slider 13 is stuck in the pit at the upper end of the top block 19. At this time, the PDC drill bit 18 and the roller drill bit 16 are completely in the same horizontal position, and the roller drill bit 16 and the PDC drill bit 18 can be used to drill synchronously; (3) When the PDC drill bit 18 is required for drilling, Fig.10As shown, when the drill bit is close to the bottom of the well, the drilling fluid is circulated with the maximum displacement to clean the bottom of the well, and then the drill bit is lowered to the bottom of the well to start rotary drilling. In this process, the upper and lower sliders 13 are thrown to the outermost edge and contact the inner wall of the cavity 5 under the action of centrifugal force (greater than the compression force of the spring 12), and completely occupy the outer space of the cavity 5, so that the top block 19 can only push to the bottom end of the lower slider 13, and the positioning boss at the bottom end of the upper slider 13 is stuck in the pit at the upper end of the lower slider 13, and the positioning boss at the bottom end of the lower slider 13 is stuck in the pit at the upper end of the top block 19. At this time, the PDC drill bit 18 is at the lowest position, and the PDC drill bit 18 can be used for drilling.

[0027] Example 4

[0028] The composite drill bit of the present invention is capable of changing the rock cutting mode without drilling, and an annular top block 19 is provided at the upper end of a movable seat 14, close to the inner wall of a cavity 5, and two symmetrical U-shaped grooves IV are provided in the top block 19, and the U-shaped grooves IV are used in conjunction with a horizontal axis 11; the rest is the same as in Example 3.

Claims

1. A composite drill bit capable of changing the rock cutting mode without drilling, comprising a drill bit base body (1), and a straightening edge axially arranged around the drill bit base body (1) and fixed thereto as an integral unit, characterized in that The straightening ridge is composed of two or more fixed drill bit mounting seats (2) and two or more convex ridges (3) arranged alternately, the length of the fixed drill bit mounting seats (2) being greater than the lower edge of the drill bit base (1); the upper part of the drill bit base (1) is a drill tool connector (4), and the interior of the lower part thereof is a cavity (5); a movable seat (14) is mounted in the cavity (5), and two or more longitudinal movable drill bit mounting seats (6) are evenly distributed and fixed below the movable seat (14) and correspond to the positions of the convex ridges (3); a moving channel (7) is formed between the movable drill bit mounting seats (6) and below the movable seat (14); a guide tube (8) is provided in the drill tool connector (4) and passes through the cavity (5) and the movable seat (14), and the lower end of the guide tube (8) is placed in the moving channel (7); and a plurality of guide holes (9) are evenly arranged around the outer wall of the middle and lower sections of the guide tube (8).

2. A composite drill bit for changing the rock cutting mode without drilling according to claim 1, characterized in that One or more limiting holes are provided at the lower end of the convex ridge (3), a suspension sleeve (15) is installed on the inner circumference of the cavity (5), a fixing hole is provided on the outer wall of the suspension sleeve (15) and matches with the limiting hole, and is fixed by bolts (20), and the suspension sleeve (15) is used to limit the downward movement of the movable seat (14).

3. The composite drill bit for changing the rock cutting mode without drilling according to claim 1, characterized in that: The lower end of the movable drill bit mounting seat (6) is equipped with a drill bit.

4. The composite drill bit for changing the rock cutting mode without drilling according to claim 1, characterized in that: Each of the movable drill bit mounting seats (6) is provided with a longitudinal guide groove (17), the guide groove (17) passes through the movable seat (14) and the guide hole (9) to form a fluid channel, and its lower end is connected to the nozzle.

5. A composite drill bit for changing the rock cutting mode without drilling according to claim 1, 2, 3 or 5, characterized in that One or more mounting holes (10) are provided at the upper end of the convex ridge (3), a transverse axis (11) is installed in the mounting hole (10), and the front end of the transverse axis (11) is placed in a recessed pit on the outer wall of the flow guide tube (8), and a spring (12) and a slider (13) are sequentially mounted on the transverse axis (11).

6. A composite drill bit for changing the rock cutting mode without drilling according to claim 5, characterized in that A PDC drill bit (18) is installed at the bottom end of the fixed drill bit mounting seat (2), a roller drill bit (16) is installed at the bottom end of the movable drill bit mounting seat (6), and a top block (19) which is consistent with the direction of each of the above-mentioned sliders (13) is fixed at the center position of the upper end of the movable seat (14). The top block (19) is a U-shaped structure, and the U-shaped groove I therein is used in conjunction with the horizontal axis (11), and the inner side of the top block (19) is in contact with the outer wall of the guide tube (8), so that the guide hole (9), the U-shaped groove I, and the guide groove (17) form a fluid channel.

7. A composite drill bit for changing the rock cutting mode without drilling according to claim 5, characterized in that A roller drill bit (16) is mounted at the bottom end of the fixed drill bit mounting seat (2), a PDC drill bit (18) is mounted at the bottom end of the movable drill bit mounting seat (6), and a top block (19) is fixed at the upper end of the movable seat (14) and close to the inner wall of the cavity (5) in the same direction as the above-mentioned sliders (13). The top block (19) is a U-shaped structure, and the U-shaped groove III therein cooperates with the horizontal axis (11).

8. A composite drill bit for changing the rock cutting mode without drilling according to claim 6 or 7, characterized in that The height of the top block (19) is greater than or equal to the height of all the sliders (13) stacked together, and the width of the top block (19) is less than the width of the sliders (13).

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