A geological drilling pdc bit

Abstract

The application relates to the technical field of drilling equipment, and discloses a geological drilling PDC drill bit, which comprises a limiting plate, the limiting plate is connected with a sand blocking cylinder with a filter screen at the bottom through a two-link structure, the upper portion of the sand blocking cylinder is provided with a limiting structure for avoiding the sand blocking cylinder from penetrating through a water nozzle, the two-link structure is composed of two links, the end portions of the two links are connected through a middle rotating shaft, when the limiting structure of the sand blocking cylinder abuts against the end portion of a mounting hole, the middle rotating shaft of the two-link structure is deviated to one side. The geological drilling PDC drill bit blocks the water nozzle by means of the sand blocking cylinder, effectively prevents the silt from entering the water nozzle, avoids the blockage of the water nozzle, meanwhile, the two-link structure supports and drives the sand blocking cylinder to move, so that the sand blocking cylinder can be repeatedly used and will not fall to the bottom of the well, and the drilling is not affected, meanwhile, the two-link structure has great rigidity when being unfolded, the sand blocking cylinder can be ensured from being affected by external silt, and when being folded, the sand blocking cylinder can be ensured from being separated from the water nozzle, and the reliability is higher.

Description

Technical Field

[0001] This application relates to the field of drilling equipment technology, and in particular to a geological drilling PDC drill bit. Background Technology

[0002] PDC (polycrystalline diamond composite) drill bits are a core tool in modern drilling operations and are widely used in oil and gas exploration due to their advantages such as high mechanical drilling speed and long service life.

[0003] During geological drilling, drill bits inevitably need to be lowered into the well midway due to tasks such as changing drill bits and handling accidents. If circulation is not established beforehand or the flow rate is insufficient, the mud cake scraped from the wellbore will accumulate directly at the bottom of the drill bit, clogging the water channels. Therefore, measures need to be taken to prevent water channel blockage during mid-drilling. A common measure is to add a wire mesh cover to the entire drill bit. When the drill bit reaches the bottom of the well, the strong mud pressure during drilling destroys the connection between the mesh cover and the drill bit, causing the mesh cover to fall to the bottom of the well without affecting normal mud injection.

[0004] Although using wire mesh can effectively reduce water hole clogging, metal mesh falling to the bottom of the well may affect the normal drilling of the drill bit. At the same time, due to the uneven hydraulic distribution in different water hole areas of the drill bit, the mesh connection of each water hole is not as strong. There is a probability that the mesh will fall off under mud pressure, and there is also a probability that some meshes will not fall off, affecting mud injection. Summary of the Invention

[0005] This application proposes a geological drilling PDC drill bit that uses a sand trap to seal the water nozzle, effectively preventing mud and sand from entering the water nozzle and avoiding blockage. At the same time, a two-link structure supports and drives the movement of the sand trap, allowing it to be reused continuously without falling to the bottom of the well and affecting drilling. Furthermore, the two-link structure has high rigidity when not folded, ensuring that the sand trap is not affected by external mud and sand. When folded, it ensures that the sand trap is detached from the water nozzle, further enhancing reliability.

[0006] To achieve the above objectives, this application adopts the following technical solution: a geological drilling PDC drill bit, comprising a drill bit housing, the drill bit housing having several blades and mounting holes, a water nozzle installed in the mounting holes, a water cavity inside the drill bit housing, the water cavity being connected to a water pump, a limiting plate being provided in the water cavity, the limiting plate being connected to a sand-trapping cylinder with a filter screen at the bottom via a two-bar linkage structure, the upper part of the sand-trapping cylinder having a limiting structure to prevent the sand-trapping cylinder from passing through the water nozzle, the two-bar linkage structure consisting of two connecting rods, the ends of the two connecting rods being connected by an intermediate rotor. When the limiting structure of the sand-blocking cylinder is pressed against the end of the mounting hole, the middle rotating shaft of the two-link structure is biased to one side. The drill bit housing is provided with a limiting component, which can restrict the middle rotating shaft of the two-link structure from continuing to move to one side. The drill bit housing is also provided with a telescopic component and a driving structure. When the drill bit is lowered into the well, the telescopic component remains in the extended state and retracts under the mud pressure during drilling. When the telescopic component retracts, it triggers the action of the limiting component, which releases the limiting component from restricting the middle rotating shaft of the two-link structure, and the driving structure drives the two-link structure to continue folding.

[0007] Preferably, the telescopic component includes a telescopic cavity and a telescopic rod. The telescopic rod is connected to a limiting block via a connecting arm. The limiting block is located on the moving path of the intermediate rotating shaft of the two-bar structure. The limiting block moves as the telescopic rod contracts and leaves the moving path of the intermediate rotating shaft after moving.

[0008] Preferably, the driving structure is an elastic pull rope, and the two ends of the elastic pull rope are fixedly connected to the two ends of the two-bar linkage structure, respectively.

[0009] Preferably, the driving structure is a cantilever rod, which is fixedly connected to the connecting arm. The connecting arm is located below the moving path of the intermediate rotating shaft. As the telescopic rod continues to retract, the cantilever rod moves with the intermediate rotating shaft, causing the two-bar linkage structure to fold, making it easier to install.

[0010] Preferably, the telescopic component further includes an air cavity, which is annular and located on the limiting plate. The air cavity is connected to the top of the telescopic cavity, and both the telescopic cavity and the air cavity are filled with gas to increase the telescopic range of the component.

[0011] Preferably, the sand-blocking cylinder includes a cylinder body and a pressure plate. The cylinder body is fixedly connected to a bottom plate. The pressure plate is connected to a limiting plate. The bottom plate is fixedly connected to a sliding rod. The sliding rod is inserted into the pressure plate and slidably connected to the pressure plate. The pressure plate or the bottom plate is provided with an adjusting bolt. Rotating the adjusting bolt can move the pressure plate and the bottom plate away from each other.

[0012] Preferably, a gap is left between the cylinder and the water nozzle.

[0013] Preferably, the lower end of the cylinder is provided with a sealing bladder, the cylinder is connected to the bottom plate through the front bladder, and the bottom plate communicates with the sealing bladder.

[0014] The beneficial effects of this invention are as follows:

[0015] This application provides a geological drilling PDC drill bit that utilizes a sand trap to seal the water nozzle, effectively preventing mud and sand from entering the water nozzle and avoiding blockage. At the same time, a limiting component prevents the folding of the two-link structure, thereby preventing the sand trap from retracting into the drill bit housing under pressure. During drilling, the high pressure drives the telescopic component to contract, releasing the restriction on the folding of the two-link structure and allowing it to fold rapidly. This causes the sand trap to detach from the water nozzle, without affecting the injection of drilling mud. The sand trap can be reused repeatedly without falling to the bottom of the well and without affecting drilling.

[0016] The contraction of the telescopic component releases the restriction on the folding of the two-link structure by the limiting component, thus allowing the two-link structure to fold. On the one hand, the two-link structure has greater rigidity when folded, which can ensure that the sand-blocking cylinder is not affected by external mud and sand, and the function of blocking mud and sand will not fail. On the other hand, after the restriction is released, a small force is enough to fold the two-link structure, ensuring that the sand-blocking cylinder is detached from the water nozzle, which is more reliable. Attached Figure Description

[0017] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on the provided drawings without creative effort:

[0018] Figure 1 This is a schematic diagram of Embodiment 1 of the present invention;

[0019] Figure 2 This is a three-dimensional structural diagram of Embodiment 1 of the present invention;

[0020] Figure 3 This is a schematic diagram of Embodiment 2 of the present invention;

[0021] Figure 4 This is a schematic diagram of the limiting member and the telescopic member in Embodiment 2 of the present invention;

[0022] Figure 5 For the present invention Figure 4 A bottom view;

[0023] Figure 6 For the present invention Figure 5 A schematic diagram showing the rotation direction of the two-bar linkage structure not facing the central axis.

[0024] Figure 7 This is a schematic diagram of the sand-trapping cylinder in Embodiment 2 of the present invention.

[0025] In the diagram: 1. Drill bit housing; 2. Cutting blade; 3. Mounting hole; 4. Water nozzle; 5. Sand trap; 51. Cylinder body; 52. Pressure plate; 53. Adjusting bolt; 54. Base plate; 55. Front bladder; 56. Sliding rod; 57. Sealing bladder; 6. Limiting plate; 7. Two-bar linkage structure; 8. Limiting component; 81. Connecting arm; 82. Limiting block; 83. Cantilever rod; 9. Telescopic component; 91. Telescopic cavity; 92. Telescopic rod; 93. Air chamber; 10. Elastic pull rope. Detailed Implementation

[0026] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0027] Example 1, as Figures 1-2A geological drilling PDC drill bit includes a drill bit housing 1, which has several cutter wings 2 and mounting holes 3. The cutter wings 2 are equipped with PDC teeth. A water nozzle 4 is installed in the mounting holes 3. A water cavity is provided inside the drill bit housing 1, which is connected to a water pump. The water pump delivers mud into the water cavity and sprays it to the bottom of the well through water nozzles. A limiting plate 6 is provided in the water cavity and is fixedly connected to the inner wall of the drill bit housing 1. The limiting plate 6 can be welded to the inner wall of the drill bit housing 1 or installed in the drill bit housing through pre-drilled mounting holes. In section 1, the limiting plate 6 is connected to a sand-blocking cylinder 5 via a two-bar linkage structure 7. The sand-blocking cylinder 5 is a hollow cylinder with a filter screen at its bottom, allowing mud to pass through while preventing external mud and sand from entering the drill bit housing 1. The sand-blocking cylinder 5 can be inserted from the top of the water nozzle 4. A limiting structure is provided at the top of the sand-blocking cylinder 5 to prevent it from passing through the water nozzle 4. The two-bar linkage structure 7 consists of two connecting rods, the ends of which are connected by an intermediate pivot. The upper end of the two-bar linkage structure 7 is hinged to the limiting plate 6. Next, the lower end of the two-link structure 7 is hinged to the sand-blocking cylinder 5. When the limiting structure of the sand-blocking cylinder 5 abuts against the end of the mounting hole 3, the middle rotating shaft of the two-link structure 7 is biased to one side. The drill bit housing 1 is provided with a limiting member 8, which can restrict the middle rotating shaft of the two-link structure 7 from continuing to move to one side. Since the middle rotating shaft of the two-link structure 7 cannot continue to move, that is, the two-link structure 7 cannot continue to fold, and the two ends of the two-link structure 7 cannot continue to approach each other, so that the sand-blocking cylinder 5 will not retreat under the external mud pressure, ensuring that the external mud and sand are protected. It will not enter the water nozzle 4. The drill bit housing 1 is also equipped with a telescopic component 9 and a drive structure. When going down into the well, the telescopic component 9 can overcome the low pressure of the mud and remain in the extended state. When drilling, the telescopic component 9 contracts under the high pressure of the mud. When the telescopic component 9 contracts, it triggers the action of the limiting component 8, which releases the limiting component 8 from the restriction of the intermediate shaft of the two-link structure 7. After the limiting component 8 releases the restriction of the intermediate shaft, the drive structure drives the two-link structure 7 to continue to fold, so that the sand-blocking cylinder 5 leaves the water nozzle 4 without affecting the normal injection of mud.

[0028] Please see Figure 4 The telescopic component 9 includes a telescopic cavity 91 and a telescopic rod 92. The telescopic rod 92 is connected to a limiting block 82 via a connecting arm 81. The limiting block 82 is located on the movement path of the intermediate rotating shaft of the two-link structure 7. When the intermediate rotating shaft of the two-link structure 7 moves to one side, it will press against the limiting block 82. The limiting block 82 will restrict the two-link structure 7 from further folding. The limiting block 82 and the connecting arm 81 move as the telescopic rod 92 retracts. After the limiting block 82 moves away from the movement path of the intermediate rotating shaft, the two-link structure 7 can be further folded, and the sand-blocking cylinder 5 is pulled out from the water nozzle 4.

[0029] The driving structure is an elastic pull rope 10. The two ends of the elastic pull rope 10 are fixedly connected to the two ends of the two-link structure 7. When the limit block 82 leaves, the two ends of the two-link structure 7 quickly move closer together under the pulling force of the elastic pull rope 10, causing the sand-blocking cylinder 5 to leave the water nozzle 4.

[0030] In Example 2, because the elasticity of the elastic rope 10 is always present in Example 1, the sand-blocking cylinder 5 always tends to detach from the water nozzle 4, making installation inconvenient. Therefore, based on Example 1, the setting of the drive structure is changed. Please refer to Example 2. Figures 3-5 In the second embodiment, the driving structure is a lifting rod 83, which is fixedly connected to the connecting arm 81. The connecting arm 81 is located below the intermediate rotating shaft. When the limiting block 82 leaves, as the telescopic rod 92 continues to retract, the lifting rod 83 contacts the intermediate rotating shaft, and the lifting rod 83 lifts the intermediate rotating shaft, causing the two-link structure 7 to fold.

[0031] The two-bar linkage structure 7 and the limiting member 8 in Embodiments 1 and 2 are flexibly arranged according to the position of the mounting hole 3. For example, in Figure 5 In the case where the drill bit inner diameter is small, the rotation direction of the two-link structure 7 is not towards the central axis. The connecting arm 81 is adaptively adjusted to correspond to the rotation direction of the central axis of the two-link structure 7. In other embodiments, the folding directions of each two-link structure 7 may be different. The connecting arm 81 is adapted to correspond to the setting method of each two-link structure 7 to ensure that the limiting block 82 is on the moving path of the central rotation and can leave without interfering with the folding of the two-link structure 7. The lifting rod 83 is always on the moving path of the central axis and moves with the central axis.

[0032] The telescopic component 9 also includes an air chamber 93, which is annular and located on the limiting plate 6. The air chamber 93 is connected to the top of the telescopic cavity 91. Both the telescopic cavity 91 and the air chamber 93 are filled with gas, which can be air. The initial air pressure causes the telescopic rod 92 to be in the extended state. When the mud pressure increases, the pressure compresses the gas, causing the telescopic rod 92 to contract. The air chamber 93 increases the gas volume. When the air chamber 93 contracts, the change in gas volume is relatively small, making it easier to compress.

[0033] Please see Figure 7The sand-trapping cylinder 5 includes a cylinder body 51 and a pressure plate 52. The cylinder body 51 is fixedly connected to a bottom plate 54. The pressure plate 52 is connected to a limiting plate 6. The bottom plate 54 is fixedly connected to a sliding rod 56. The sliding rod 56 is inserted into the pressure plate 52 and slidably connected to the pressure plate 52. The end of the sliding rod 56 is provided with a limiting structure to prevent the sliding rod 56 from disengaging from the pressure plate 52. The pressure plate 52 (bottom plate 54) is provided with an adjusting bolt 53. The end of the bottom plate 53 abuts against the bottom plate 54 (pressure plate 52). By rotating the adjusting bolt 53, the pressure plate 52 and the bottom plate 54 are moved away from each other, thereby causing the two-link structure 7 to fold slightly. The middle pivot abuts against the limiting block 82 to prevent the sand-trapping cylinder 5 from shaking. If the bottom plate 53 is installed on the bottom plate 54, then the filter screen at the bottom of the cylinder body 51 should be detachably connected. When tightening the bottom plate 53, the filter screen should be removed first, the bottom plate 53 should be tightened, and then it should be installed.

[0034] A gap is left between the cylinder 51 and the water nozzle 4 to facilitate the insertion of the sand-blocking cylinder 5 into the water nozzle 4. However, mud and sand may enter the gap, hindering the sand-blocking cylinder 5 from being pulled out of the water nozzle 4. The lower end of the cylinder 51 is provided with a sealing bladder 57. The cylinder 51 is connected to the bottom plate 54 through the front bladder 55. When the bottom plate 53 is tightened, the pressure of the pressure plate 52 on the bottom plate 54 increases, and the bottom plate 54 communicates with the sealing bladder 57. The gas in the bottom plate 54 causes the sealing bladder 57 to expand, sealing the gap between the side wall of the cylinder 51 and the water nozzle 4. When the two-link structure 7 is folded, the pressure plate 52 and the bottom plate 54 move away first, the pressure on the bottom plate 54 decreases, the sealing bladder 57 retracts, and the sand-blocking cylinder 5 can be easily pulled out.

[0035] The above description of the disclosed embodiments enables those skilled in the art to make or use the invention. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the invention. Therefore, the invention is not to be limited to the embodiments shown herein, but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A geological drilling PDC drill bit, comprising a drill bit housing (1), wherein the drill bit housing (1) is provided with a plurality of cutter wings (2) and mounting holes (3), wherein a water nozzle (4) is installed in the mounting holes (3), and a water cavity is provided inside the drill bit housing (1), the water cavity being connected to a water pump, characterized in that: The water cavity is provided with a limiting plate (6), and the limiting plate (6) is connected to a sand-blocking cylinder (5) with a filter screen at the bottom through a two-bar linkage structure (7). The upper part of the sand-blocking cylinder (5) is provided with a limiting structure to prevent the sand-blocking cylinder (5) from passing through the water nozzle (4). The two-bar linkage structure (7) consists of two connecting rods, and the ends of the two connecting rods are connected by a central rotating shaft. When the limiting structure of the sand-blocking cylinder (5) is pressed against the end of the mounting hole (3), the central rotating shaft of the two-bar linkage structure (7) is biased to one side. The drill bit housing (1) The drill bit housing (1) is provided with a limiting member (8), which can limit the middle shaft of the two-link structure (7) from continuing to move to one side. The drill bit housing (1) is also provided with a telescopic member (9) and a drive structure. When the drill bit is lowered into the well, the telescopic member (9) remains in the extended state and retracts under the mud pressure during drilling. When the telescopic member (9) retracts, it triggers the action of the limiting member (8), so that the limiting member (8) releases the restriction on the middle shaft of the two-link structure (7), and the drive structure drives the two-link structure (7) to continue to fold. The telescopic component (9) includes a telescopic cavity (91) and a telescopic rod (92). The telescopic rod (92) is connected to a limiting block (82) via a connecting arm (81). The limiting block (82) is located on the moving path of the intermediate rotating shaft of the two-bar structure (7). The limiting block (82) moves as the telescopic rod (92) contracts and leaves the moving path of the intermediate rotating shaft after moving. The sand-blocking cylinder (5) includes a cylinder body (51) and a pressure plate (52). The cylinder body (51) is fixedly connected to a bottom plate (54). The pressure plate (52) is connected to a limiting plate (6). The bottom plate (54) is fixedly connected to a sliding rod (56). The sliding rod (56) is inserted into the pressure plate (52) and slidably connected to the pressure plate (52). The pressure plate (52) or the bottom plate (54) is provided with an adjusting bolt (53). Rotating the adjusting bolt (53) can make the pressure plate (52) and the bottom plate (54) move away from each other. There is a gap between the cylinder body (51) and the water nozzle (4). The lower end of the cylinder body (51) is provided with a sealing bladder (57). The cylinder body (51) is connected to the bottom plate (54) through a front bladder (55). The bottom plate (54) is connected to the sealing bladder (57).

2. The geological drilling PDC drill bit according to claim 1, characterized in that, The driving structure is an elastic pull rope (10), and the two ends of the elastic pull rope (10) are fixedly connected to the two ends of the two-bar linkage (7).

3. The geological drilling PDC drill bit according to claim 1, characterized in that, The driving structure is a cantilever rod (83), which is fixedly connected to the connecting arm (81). The connecting arm (81) is located below the moving path of the intermediate rotating shaft. As the telescopic rod (92) continues to retract, the cantilever rod (83) moves with the intermediate rotating shaft, causing the two-bar linkage structure (7) to fold.

4. A geological drilling PDC drill bit according to claim 2 or 3, characterized in that, The telescopic component (9) also includes an air cavity (93), which is annular and located on the limiting plate (6). The air cavity (93) is connected to the top of the telescopic cavity (91), and the telescopic cavity (91) and the air cavity (93) are filled with gas.

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