Double-support PDC-roller mixed drill bit

Abstract

The utility model belongs to the technical field of petroleum and geological drilling tools, and particularly relates to a double-support PDC-roller mixed drill bit. The double-support PDC-roller hybrid drill bit comprises a drill bit body used for being connected with a drill column; the PDC assembly is arranged on the drill bit body; the drill bit comprises a drill bit body and a roller assembly arranged on the drill bit body, the roller assembly comprises a roller palm arm fixedly connected to the drill bit body, a roller shaft is arranged on the roller palm arm, a rolling wheel is rotationally arranged on the roller shaft, and a sealing assembly is arranged between the roller shaft and the rolling wheel. The sealing assembly comprises a first sealing piece and a second sealing piece, the hardness of the first sealing piece is larger than that of the second sealing piece, sealing is formed between the first sealing piece and the second sealing piece, and dynamic sealing is formed between the first sealing piece and the roller shaft. Static sealing is formed between the second sealing piece and the rolling wheel.

Description

[0001] Cross-references to related applications

[0002] This application claims priority to international patent application PCT / CN2023 / 139329, filed on December 18, 2023, entitled “A PDC-Roller Hybrid Drill Bit”, the entire contents of which are incorporated herein by reference. Technical Field

[0003] This utility model belongs to the field of petroleum and geological drilling tool technology, specifically, it relates to a dual-support PDC-roller hybrid drill bit. Background Technology

[0004] PDC drill bits perform well in soft to medium-hard formations and are widely used in oil and geological drilling. However, in some medium to hard formations, especially heterogeneous formations, PDC drill bits suffer from lower mechanical drilling rates and shorter lifespans. In directional wells, horizontal wells, extended reach wells, and branch wells, tool face instability is a problem, particularly in low-inclination wells, often requiring the use of roller cone bits for initial directional drilling. This is a bottleneck issue for PDC drill bits in these applications and urgently needs to be addressed. In heterogeneous formations, especially in medium to high-strength formations, roller cone bits are prone to tooth breakage, resulting in slow mechanical drilling rates and limited footage, which is another bottleneck issue that urgently needs to be resolved.

[0005] PDC-roller cone hybrid drill bits combine the advantages of both PDC and roller cone drill bits, achieving some success in increasing speed and improving directional efficiency. However, these drill bits still face challenges such as short service life, low lifespan, and premature failure of the roller cone portion. Compared to roller cones, rollers have an additional bearing housing, resulting in a significantly longer lifespan. Dual-support PDC-roller hybrid drill bits offer a much longer lifespan than existing PDC-roller cone hybrid drill bits, further enhancing speed and efficiency. However, current roller-roller shaft seals suffer from short lifespans. To improve the lifespan of these seals, they are typically made of metal. However, metal seals require significant sealing force. When metal seals are installed at both ends of the roller shaft, the structural characteristics of the rollers and roller shaft in a dual-support PDC-roller hybrid drill bit limit the amount of sealing force that can be provided to only one metal seal, leading to seal failure. Utility Model Content

[0006] In view of the technical problems mentioned above, the present invention aims to provide a dual-support PDC-roller hybrid drill bit, which can solve at least one of the above problems.

[0007] According to this utility model, a dual-support PDC-roller hybrid drill bit is provided, comprising:

[0008] The drill bit body used to connect the drill string;

[0009] The PDC assembly disposed on the drill bit body; and

[0010] The roller assembly is provided on the drill bit body. The roller assembly includes a roller arm fixedly connected to the drill bit body. A roller shaft is provided on the roller arm. The end of the roller shaft away from the roller arm is connected to the drill bit body through an elastic support ring. A rolling wheel is rotatably provided on the roller shaft. A sealing assembly is provided between the roller shaft and the rolling wheel.

[0011] The sealing assembly includes a first sealing element and a second sealing element. The hardness of the first sealing element is greater than that of the second sealing element. A seal is formed between the first sealing element and the second sealing element. A dynamic seal is formed between the first sealing element and the roller shaft. A static seal is formed between the second sealing element and the roller.

[0012] In one specific embodiment, a static seal is formed between the radial outer side of the first seal and the radial outer side of the second seal.

[0013] In one specific embodiment, the first seal and the second seal are an integral structure.

[0014] In one specific embodiment, the first seal has higher wear resistance than the second seal.

[0015] In one specific embodiment, the frictional resistance of the first seal is lower than that of the second seal.

[0016] In one specific embodiment, an oil bladder and an oil passage are provided inside the roller arm, and the oil passage is configured to allow the oil in the oil bladder to flow to the contact surface between the roller shaft and the roller.

[0017] In one specific embodiment, an oil cup is provided inside the roller palm arm, the oil bladder is located inside the oil cup, and a balance hole is provided inside the roller palm arm to connect the oil cup with the outside.

[0018] In one specific embodiment, the balance hole connects the space between the rolling wheel and the rolling arm to the oil cup.

[0019] In one specific embodiment, a first plug is provided at the end of the oil cup away from the balance hole, and an oil injection hole is provided on the first plug, which communicates with the interior of the oil bladder.

[0020] In one specific embodiment, both ends of the roller shaft extend beyond the rolling wheel. One end of the roller shaft is fixedly connected to the roller arm. A bearing seat is provided on the PDC assembly. The other end of the roller shaft is rotatably connected to the bearing seat. The two sealing assemblies are respectively provided at the two ends of the roller shaft.

[0021] The advantages of this utility model are as follows.

[0022] According to the present invention, the dual-support PDC-roller hybrid drill bit first breaks the formation rock during operation, forming defects such as cracks in the formation and reducing the breaking strength of the formation rock. Then, the PDC component cutting teeth cut the formation rock that has been pre-broken, cracked, and weakened.

[0023] Under the action of the balance hole and oil bladder, the lubricating oil or grease in the oil bladder and oil passage in the oil cup is continuously replenished to the roller shaft, rolling wheel, shaft seat and seal, etc., keeping the roller shaft, rolling wheel, shaft seat and seal working under fully lubricated conditions, which greatly improves the life of the roller and the dual support PDC-roller hybrid drill bit.

[0024] The sealing assembly includes a first seal and a second seal with different physical properties, which achieves the purpose of each part fulfilling its own function and greatly improves the life of the sealing ring. Attached Figure Description

[0025] The present invention will now be described with reference to the accompanying drawings.

[0026] Figure 1 The structure of the dual-support PDC-roller hybrid drill bit according to the present invention is schematically shown;

[0027] Figure 2 for Figure 1 Enlarged structural schematic diagram of the central sealing assembly;

[0028] Figure 3 A schematic top view of the dual-support PDC-roller hybrid drill bit according to the present invention is shown.

[0029] In the diagram: 1. Drill bit body; 11. Roller area; 12. PDC area;

[0030] 2. Connecting joint; 21. Shackle groove;

[0031] 3. Roller assembly; 31. Roller arm; 311. Oil bladder; 312. Oil passage; 314. Balance hole; 315. Oil cup; 316. First plug; 317. Oil filling hole; 32. Roller shaft; 323. Second plug; 33. Roller; 331. Roller caliper teeth; 332. First caliper protection teeth; 34. Roller teeth; 35. Shaft seat; 30. Elastic support ring;

[0032] 4. PDC assembly; 41. Blade; 42. Cutting teeth; 43. Sizing block; 431. Second sizing tooth; 44. Active sizing tooth;

[0033] 6. Sealing assembly; 6. First seal; 62. Second seal;

[0034] 7. Second auxiliary cutting tooth;

[0035] 8. Central flow channel;

[0036] 9. Nozzle;

[0037] 10. First auxiliary cutting tooth;

[0038] 100. Dual-support PDC-roller hybrid drill bit.

[0039] In this application, all the accompanying drawings are schematic drawings, used only to illustrate the principle of the present invention, and are not necessarily drawn to scale. Detailed Implementation

[0040] The present invention will now be described with reference to the accompanying drawings.

[0041] In this application, it should be noted that the directional terms or qualifiers such as "up" and "down" used in this application are all in reference to the appendix. Figure 1 In other words, they are not used to define the absolute position of the components involved, but can vary depending on the specific circumstances.

[0042] Figure 1 The structure of the dual-support PDC-roller hybrid drill bit 100 according to this utility model is schematically shown. Figure 1 As shown, the dual-support PDC-roller hybrid drill bit 100 includes a drill bit body 1, a roller assembly 3, and a PDC assembly 4. The drill bit body 1 is generally cylindrical, and its lower end is equipped with a connecting joint 2 for connecting to a drill string (not shown) that drives the drill bit body 1 to rotate. The connecting joint 2 allows the drill bit body 1 to be connected to the drill string, enabling it to be lowered into the well along with the drill string and rotate circumferentially with it.

[0043] The drill body 1 is divided into two parts by a plane passing through its axis: a roller area 11 and a PDC area 12. The roller assembly 3 is mounted on the upper part of the roller area 11 of the drill body 1, facing the working end face. Figure 1 The upper end face of the drill bit body 1). The PDC assembly 4 is located on the upper part of the PDC area 12 of the drill bit body 1, and the PDC assembly 4 faces the working end face.

[0044] According to this utility model, the roller assembly 3 includes a roller arm 31 fixedly connected to the drill bit body 1, a roller shaft 32 fixedly connected to the roller arm 31, a roller 33 mounted under the roller shaft 32, and roller teeth 34 embedded under the roller 33. In this embodiment, the roller shaft 32 is fixedly disposed at the upper end of the roller arm 31, and the roller shaft 32 is configured to extend obliquely approximately along the radial direction of the drill bit body 1 and the direction of the PDC assembly 4. The roller 33 is generally spherical. A hole is provided inside the roller 33 to allow the roller shaft 32 to be inserted, so that the roller 33 can be fitted onto the roller shaft 32.

[0045] like Figure 1 As shown, in this embodiment, one end of the roller shaft 32 is fixedly connected to the roller arm 31, and the other end of the roller shaft 32 (the end away from the roller arm 31) is connected to the drill body 1. In this configuration, the drill body 1 and the roller arm 31 are fixed to both ends of the roller shaft 32, thereby improving the stability and load-bearing capacity of the roller shaft 32.

[0046] In this embodiment, the roller shaft 32 and the roller arm 31 are an integral structure, and the roller shaft 32 is connected to the drill body 1 by a plug-in connection. Further, the roller shaft 32 is connected to the drill body 1 via an elastic support ring 30. Specifically, a bearing seat 35 is fixedly provided on the drill body 1, and the elastic support ring 30 is coaxially sleeved within the bearing seat 35. The roller shaft 32 is disposed within the bearing seat 35 via the elastic support ring 30, that is, the elastic support ring 30 is disposed between the roller shaft 32 and the bearing seat 35.

[0047] The roller shaft 32 can maintain effective contact with the bearing seat 35 at all times through the elastic support ring 30. In this embodiment, the elastic support ring 30 makes the support force of the bearing seat 35 on the roller shaft 32 continuous and effective, which greatly improves the stress and deformation state of the roller shaft 32, which is conducive to significantly improving the life of the roller 33, sealing assembly 6, etc., and thus improving the life of the dual-support PDC-roller hybrid drill bit 100.

[0048] If the roller shaft 32 is directly inserted into the bearing seat 35, the following problems will occur: First, when an interference fit is used between the roller shaft 32 and the bearing seat 35, assembly will be difficult. Second, when an intermediate fit is used between the roller shaft 32 and the bearing seat 35, although assembly is simple, a gap will exist between the roller shaft 32 and the bearing seat 35. During the drill bit cutting the formation, the roller shaft 32 will vibrate and impact the bearing seat 35, thus aggravating the damage to the roller shaft 32. The elastic support ring 30 itself is elastic. When the elastic support ring 30 is placed between the roller shaft 32 and the bearing seat 35, the inner side of the elastic support ring 30 can abut against the roller shaft 32, and the outer side of the elastic support ring 30 can abut against the bearing seat 35, thereby ensuring that the roller shaft 32 is always supported by the bearing seat 35, and the elastic support ring 30 can play a shock-absorbing role when the roller shaft 32 vibrates.

[0049] Furthermore, the elastic support ring 30 can be a ring with a grooved inner wall, a ring with a grooved outer wall, a ring with a hole in the middle of the ring wall, a ring with other structural gaps and combinations, or a wire-wound ring.

[0050] According to this utility model, a sealing assembly 6 is provided between the rolling wheel 33 and the rolling wheel shaft 32. For example... Figure 2 As shown, the sealing assembly 6 includes a first seal 61 and a second seal 62 disposed on the roller shaft 32 and connected together.

[0051] According to this utility model, a static seal is formed between the radial outer side of the first sealing member 61 and the radial outer side of the second sealing member 62.

[0052] According to this utility model, the first sealing element 61 and the second sealing element 62 can be an integral structure, or they can be configured as separate structures. That is, the first sealing element 61 and the second sealing element 62 can be combined into one component, manufactured as a single part during the processing and manufacturing process. This integral structure makes the installation process more convenient. Alternatively, the first sealing element 61 and the second sealing element 62 can be manufactured as two separate parts, stacked together during installation. This separate structure makes the manufacturing of the parts more convenient.

[0053] According to this utility model, the wear resistance of the first sealing element 61 is higher than that of the second sealing element 62.

[0054] According to this utility model, the frictional resistance of the first sealing member 61 is lower than that of the second sealing member 62.

[0055] Specifically, the first seal 61 is made of a high-wear-resistant material. According to this invention, the high-wear-resistant material can be PTFE bronze, PTFE carbon fiber, PTFE copper, PTFE brass, or rubber with high hardness, wear resistance, and low friction. These materials all have high hardness and can effectively withstand the friction of formation gravel, thereby reducing the wear on the second seal 61. The second seal 62 is made of materials such as NBR (nitrile butadiene rubber), HNBR (hydrogenated nitrile butadiene rubber), and FKM (fluororubber). The first seal 61 and the second seal 62 form a composite structure, together constituting a sealing wear compensation structure. During assembly, the second seal 62 is in a compressed state, providing sufficient pressure to the first seal 61 to ensure the sealing of the first seal 61, and can also play a compensating role when the first seal 61 wears.

[0056] In this embodiment, a sealing groove for installing the sealing assembly 6 is provided on the inner wall of the rolling wheel 33, and the second sealing member 62 is installed in the sealing groove, thereby preventing the second sealing member 62 and the first sealing member 61 from moving axially.

[0057] In one embodiment of the sealing assembly 6, the connection surfaces of the first seal 61 and the second seal 62 are both constructed as polished surfaces.

[0058] like Figure 1 and Figure 3 As shown, in a preferred embodiment, the roller shaft 32 is connected to both the roller arm 31 and the PDC assembly 4 (or the drill body 1). Figure 1 As shown, the central axis of the roller shaft 32 is inclined relative to the central axis of the drill bit body 1. One axial end of the roller shaft 32 is fixedly connected to the roller arm 31, and the other axial end of the roller shaft 32 is connected to the PDC assembly 4 through the bearing seat 35. In this configuration, both axial ends of the roller shaft 32 are supported by the roller arm 31 and the PDC assembly 4, respectively, thereby enhancing the load-bearing capacity of the roller shaft 32.

[0059] Meanwhile, two sealing components 6 are respectively disposed at the two axial ends of the roller shaft 32. In the prior art, metal seals are usually used to improve the sealing life of the two axial ends of the roller shaft. However, during operation, because the pressure on the roller 33 is not perpendicular to the direction of the central axis of the roller shaft 32, the central axis of the roller 33 will be tilted at a certain angle to the central axis of the roller shaft 32. The sealing component 6 located at the end of the roller shaft 32 will be in a state where one end is subjected to a large radial compressive force, while the other is slightly compressed or even uncompressed, thus leading to seal failure. In this embodiment, the sealing component 6 is provided with a first sealing element 61 and a second sealing element 62 with different properties. During operation, the first sealing element 61, which has higher hardness, plays a supporting role and prevents the central axis of the roller 33 from being significantly offset from the central axis of the roller shaft 32. The second sealing element 62 has good elasticity and can ensure the sealing effect, so that both axial ends of the roller shaft 32 can achieve good sealing.

[0060] According to this invention, a plurality of roller teeth 34 are arranged along the circumferential surface of the roller 33, and are particularly evenly arranged. As the drill bit body 1 rotates, the roller 33 can break the formation rock through the roller teeth 34, thereby reducing the hardness of the formation rock.

[0061] According to this utility model, in a preferred embodiment, an oil bladder 311 and an oil channel 312 are provided inside the roller arm 31. The oil bladder 311 is filled with lubricating oil, and the oil channel 312 connects to the oil bladder 311. Furthermore, the oil in the oil bladder 311 can flow along the oil channel 312 to the contact surface between the roller shaft 32 and the roller 33. This arrangement reduces friction between the roller 33 and the roller shaft 32, extending the service life of the roller assembly 3. On the other hand, filling the gap between the roller 33 and the roller shaft 32 with oil prevents gravel from entering during operation and damaging the roller 33 or the roller shaft 32.

[0062] Furthermore, an oil cup 315 is provided inside the roller arm 31. The oil cup 315 is constructed as a cylindrical tube inside the roller arm 31, and an oil bladder 311 is located inside the oil cup 315. A balance hole 314 is provided inside the roller arm 31 to connect the oil cup 315 to the outside. With this arrangement, when the oil in the oil cup 315 is lost during operation, the oil bladder 311 will contract under atmospheric pressure, thereby ensuring that the oil in the oil cup 315 can flow smoothly between the roller shaft 32 and the roller 33.

[0063] In a preferred embodiment, the balancing hole 314 connects the space between the roller 33 and the roller arm 31 to the oil cup 315. For example... Figure 1As shown, there is a space between the roller arm 31 and the roller 33. The balance hole 314 connects the oil bladder 311 to the outside through this space, which ensures that the oil bladder 311 can work normally under atmospheric pressure and prevents the balance hole 314 from being blocked by rock cuttings during drilling.

[0064] In a preferred embodiment, the oil cup 315 is located off-center from the central axis of the drill bit body 1, thereby causing the oil bladder 311 to deviate from the central axis of the drill bit body 1. With this configuration, during drilling, the oil bladder 311 and the oil inside it are subjected to centrifugal force, causing the oil bladder 311 to undergo adaptive deformation. This forces the oil into the oil passage 312, thereby lubricating the contact surfaces of the roller shaft 32 and the rolling wheel 33, preventing wear on the roller shaft 32 and the rolling wheel 33, and extending the service life of the roller assembly 3.

[0065] Furthermore, the oil passage 312 connects the oil bladder 311 to the roller shaft 32 and the rolling wheel 33 from a position near the outer side of the oil bladder 311. That is, the connection point between the oil passage 312 and the oil bladder 311 is located on the radially outer side of the oil bladder 311 near the drill body 1. With this configuration, when the oil bladder 311 deforms under centrifugal force, the oil inside the oil bladder 311 can automatically enter the oil passage 312 under the action of centrifugal force, thereby enhancing the lubrication of the contact surfaces of the roller shaft 32 and the rolling wheel 33, preventing wear on the roller shaft 32 and the rolling wheel 33, and extending the service life of the roller assembly 3.

[0066] In one specific embodiment, a first plug 316 is provided at the end of the oil cup 315 away from the balance hole 314. An oil filling hole 317 is provided on the first plug 316, communicating with the interior of the oil bladder 311. An oil filling plug 318 is provided inside the oil filling hole 317. With this arrangement, when the oil bladder 311 is low on oil, the oil filling plug 318 can be removed from the oil filling hole 317, and oil can be injected into the oil cup 315 through the oil filling hole 317.

[0067] The PDC assembly 4 includes a cutter wing 41 and multiple cutting teeth 42 embedded under the cutter wing 41. The multiple cutting teeth 42 are evenly distributed under the cutter wing 41. The rolling teeth 34 are configured to extend beyond the cutting teeth 42, allowing the rolling wheel 33 to crush the rock by rotation before the PDC assembly 4 cuts the formation rock. Alternatively, the upper edge of the cutting teeth 42 can be understood as being located between the upper edge of the rolling teeth 34 and the upper edge of the rolling wheel 33. It should be noted that the working end face here refers to the surface of the rock being crushed, and the upper edge refers to the uppermost point along the axial direction of the dual-support PDC-roller hybrid drill bit 100.

[0068] During operation, the dual-support PDC-roller hybrid drill bit 100 rotates along its axis with its working end face facing the formation to be drilled. The roller assembly 3 pre-treats the fractured rock formation and creates defects such as cracks in the unfractured strata, reducing the rock's fracturing strength. Then, the PDC assembly 4 cuts the pre-fractured, cracked, and weakened rock formation. Specifically, as the dual-support PDC-roller hybrid drill bit 100 rotates along its axis, the roller 33 rotates around the roller shaft 32 under the frictional force of the formation. During rotation, the roller teeth 34 intermittently contact the formation, causing the dual-support PDC-roller hybrid drill bit 100 to vibrate periodically along its axis. Because the upper edge of the roller teeth 34 is lower than the upper edge of the cutting teeth 42, when the roller teeth 34 contact the formation, the cutting teeth 42 do not. At this time, the roller teeth 34 pre-treat and fracture the formation. When the roller 33 rotates to the point where the roller teeth 34 are no longer in contact with the formation, the cutting teeth 42 come into contact with the formation. At this time, the cutting teeth 42 cut the formation, thereby periodically performing drilling operations.

[0069] Therefore, on the one hand, the roller assembly 3 significantly reduces its workload and stress by partially and locally breaking the bottom rock. Furthermore, the oil bladder 311 and oil passage 312 further reduce friction between the roller shaft 32 and the rolling wheel 33, extending their service life. On the other hand, the cutting teeth 42 of the PDC assembly 4 cut the weakened formation rock, greatly improving its drillability and significantly reducing the stress on the cutting teeth 42. This results in a substantial increase in the service life of both the roller assembly 3 and the PDC assembly 4. Simultaneously, the rolling of the rolling wheel 33 generates periodic axial vibration, which is transmitted to the drill string, effectively improving the stability of the directional well face and the drilling pressure transmission efficiency. This significantly increases the footage, mechanical drilling rate, and directional characteristics in heterogeneous formations, greatly benefiting the acceleration and cost reduction of oil and gas field and mineral exploration and development.

[0070] In a preferred embodiment, the tooth height of the rolling tooth 34 is set to be 0.01-5 mm greater than the tooth height of the cutting tooth 42. Alternatively, the upper edge of the upper edge of the rolling tooth 34 is 0.01-5 mm lower than the upper edge of the cutting tooth 42. Within this range, high working efficiency is achieved.

[0071] In one embodiment, the connecting joint 2 at the lower end of the drill bit body 1 can be configured as a tapered connecting buckle and fixed to the drill string via a threaded connection. Simultaneously, a circumferentially circumferentially provided uncoupling groove 21 is provided on the outer wall of the tapered connecting buckle to facilitate quick disassembly between the dual-support PDC-roller hybrid drill bit 100 and the lower drill string. This structure not only facilitates installation and connection of the drill bit body 1 but also makes disassembly convenient, significantly improving assembly and disassembly efficiency.

[0072] like Figure 1As shown, both the PDC assembly 4 and the roller assembly 3 are arranged at the upper end of the drill bit body 1. Furthermore, there are one or more PDC assemblies 4 and roller assemblies 3. These one or more PDC assemblies 4 and roller assemblies 3 are arranged alternately along the circumference of the drill bit body 1. Therefore, when the drill bit body 1 rotates synchronously with the drill string, the PDC assembly 4 and roller assembly 3 can periodically and alternately perform cutting operations on the formation at the same location.

[0073] In a preferred embodiment, the PDC component 4 and the roller component 3 are arranged to be radially opposite to each other.

[0074] In a preferred embodiment, a reinforcing layer is further coated on the underside of the outer walls of the roller shaft 32, the roller 33, and the roller arm 31. The reinforcing layer is preferably made of tungsten carbide. On one hand, this tungsten carbide material has good oxidation and corrosion resistance, which can protect the roller shaft 32, the roller 33, and the roller arm 31, reducing the risk of oxidation and corrosion. On the other hand, this material has good wear resistance, which can reduce the wear resistance of the roller shaft 32 and the roller 33, thereby further improving the service life of the roller shaft 32 and the roller 33.

[0075] In one specific embodiment, the sealing surfaces of the bearing seat 35, the roller arm 31, and the roller 33, as well as the roller shaft 32, are all treated with nitriding, carburizing, carbonitriding, or boronizing. Alternatively, the material surface can be coated with tungsten carbide, or the corresponding materials used for nitriding, carburizing, carbonitriding, or boronizing can be directly used, such as carburized steel, or ceramic materials. This arrangement reduces friction and increases the sealing performance between the bearing seat 35 and the end face of the roller 33, as well as between the roller 33 and the roller arm 31.

[0076] According to this utility model, such as Figure 1 As shown, the roller arm 31 is fixedly connected to the outer wall of the drill bit body 1. For example, the roller arm 31 can be fixed to the lower part of the outer wall of the drill bit body 1 by welding.

[0077] In a preferred embodiment, the roller shaft 32 and the roller arm 31 are integrally formed. The included angle between the roller shaft 32 and the roller arm 31 is an obtuse angle, and the roller shaft 32 is arranged to extend inward and upward. This causes the roller 33 to face the working end face.

[0078] In one embodiment, the profile of the roller 33 is an arc shape, high in the middle and low on both sides. Roller teeth 34 are embedded in the middle of the roller 33 and arranged circumferentially. Multiple roller teeth 34 are provided, and the multiple roller teeth 34 are evenly distributed circumferentially. This structure of the roller assembly 3 is highly advantageous for breaking up geological rock formations. The roller 33 is mounted under the roller shaft 32 and forms a rotatable connection with the roller shaft 32.

[0079] According to this invention, the roller teeth 34 are configured as a first irregular tooth. The first irregular tooth can be a conical tooth, wedge-shaped tooth, spherical tooth, spoon-shaped tooth, or oval tooth, etc. The roller teeth 34 can be made of cemented carbide, ceramic, or PDC material. This significantly improves the adaptability of the roller assembly 3 to geological rock formations.

[0080] According to this utility model, such as Figure 1 As shown, a first diameter-protecting tooth 332 is provided on the outer wall of the roller arm 31, and the first diameter-protecting tooth 332 is embedded under the outer wall surface of the roller arm 31. Meanwhile, in a preferred embodiment, a roller diameter-adjusting tooth 331 is also provided on the outermost radial contour line of the roller 33. Thus, the first diameter-protecting tooth 332 and the roller diameter-adjusting tooth 331 effectively protect the borehole diameter drilled by the dual-support PDC-roller hybrid drill bit 100 from shrinking during drilling, thereby ensuring the drilling performance and directional performance of the dual-support PDC-roller hybrid drill bit 100.

[0081] According to the present invention, the PDC assembly 4 further includes a gauge block 43 formed on the radially outer side of the blade 41, and a second gauge tooth 431 is provided in the gauge block 43, the second gauge tooth 431 being embedded in the lower part of the gauge block 43.

[0082] The cutter wing 41 covers the drill body 1, and the gauge block 43 is preferably integrally formed with the cutter wing 41. For example, a portion of the radially outer side of the cutter wing 41 is formed as the gauge block 43.

[0083] like Figure 1 As shown, an active sizing tooth 44 can also be provided below the sizing block 43. The active sizing tooth 44 is located between the second sizing tooth 431 and the cutting tooth 42, and the maximum outer diameter of the active sizing tooth 44 is greater than or equal to the maximum outer diameter of the second sizing tooth 431. Thus, the first sizing tooth 332, the roller sizing tooth 331, the second sizing tooth 431, and the active sizing tooth 44 work together to effectively protect the diameter of the hole drilled by the dual-support PDC-roller hybrid drill bit 100 from shrinking during the drilling process, further ensuring the drilling performance and directional performance of the dual-support PDC-roller hybrid drill bit 100.

[0084] According to this invention, the PDC component 4 is made of PDC (polycrystalline diamond composite) material. Specifically, the cutter wing 41, cutting teeth 42, gauge-maintaining block 43, second gauge-maintaining tooth 431, and active gauge-maintaining tooth 44 are all made of PDC (polycrystalline diamond composite) material. This effectively ensures the strength of the PDC component 4, thereby guaranteeing the cutting performance of the dual-support PDC-roller hybrid drill bit 100.

[0085] Preferably, the cutting teeth 42 can be configured as planar teeth, conical teeth, ridged teeth, and triangular teeth, etc. This can further improve the cutting performance of the dual-support PDC-roller hybrid drill bit 100.

[0086] According to one embodiment of the present invention, such as Figure 3 As shown, a first auxiliary cutting tooth 10 may be provided under the cutter wing 41, and the first auxiliary cutting tooth 10 is located after the cutting tooth 42. Preferably, a second auxiliary cutting tooth 7 may also be provided under the cutter wing 41. Similarly, the second auxiliary cutting tooth 7 is located after the cutting tooth 42, and the second auxiliary cutting tooth 7 and the first auxiliary cutting tooth 10 are radially spaced apart from each other. It should be understood that "before" and "after" here refer to the order in which the cutting tooth 42 encounters the formation during the rotation of the drill bit body 1, and "after" the cutting tooth 42 refers to the side that lags behind the cutting tooth 42 in contacting the formation rock.

[0087] Both the first auxiliary cutting tooth 10 and the second auxiliary cutting tooth 7 are made of cemented carbide, ceramic or PDC material.

[0088] According to this utility model, such as Figure 1 As shown, a central flow channel 8 and a nozzle 9 extending axially are provided inside the drill bit body 1. The central flow channel 8, connected to the drill string, has a nozzle 9 extending to the cutter fins 41, allowing fluid from the drill string to be sprayed onto the cutter fins 41. The nozzle 9 is at a certain angle to the central flow channel 8, aligning the nozzle 9 with the working end face. Drilling fluid from the drill string can sequentially pass through the central flow channel 8 and the nozzle 9 to the formation rock surface aligned with the dual-support PDC-roller hybrid drill bit 100. On one hand, the drilling fluid sprayed from the nozzle 9 impacts the formation rock, softening it. On the other hand, the drilling fluid sprayed from the nozzle 9 cleans the roller assembly 3 and the PDC assembly 4, effectively preventing drill cuttings from adhering to the rollers 33 or the cutter fins 41, which greatly improves the mechanical drilling rate of the dual-support PDC-roller hybrid drill bit 100 and helps ensure its drilling performance.

[0089] Multiple nozzles 9 can be provided inside the drill bit body 1 to ensure the flow effect and efficiency of drilling fluid, and to ensure the cleaning and cooling of roller assembly 3 and PDC assembly 4.

[0090] In the description of this specification, references to terms such as "one embodiment," "some embodiments," "example," "specific example," or "some examples," etc., indicate that a specific feature, structure, material, or characteristic described in connection with that embodiment or example is included in at least one embodiment or example of the present invention. In this specification, illustrative expressions of the following terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples.

[0091] In the description of this utility model, it should be understood that the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of indicated technical features. Therefore, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of this utility model, "a plurality of" means two or more, unless otherwise explicitly specified.

[0092] In this utility model, unless otherwise explicitly specified and limited, the terms "installation," "connection," "linking," and "fixing," etc., should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in this utility model according to the specific circumstances.

[0093] Finally, it should be noted that the above description is merely a preferred embodiment of this utility model and does not constitute any limitation on this utility model. Although this utility model has been described in detail with reference to the foregoing embodiments, those skilled in the art can still modify the technical solutions described in the foregoing embodiments or make equivalent substitutions for some of the technical features. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this utility model should be included within the protection scope of this utility model.

Claims

1. A dual support PDC-roller hybrid drill bit, characterized by, Comprise: a drill bit body (1) for connecting a drill string; a PDC assembly (4) arranged on the drill bit body; and a roller assembly (3) arranged on the drill bit body, the roller assembly comprising a roller arm (31) fixedly connected to the drill bit body, a roller shaft (32) arranged on the roller arm (31), an end of the roller shaft (32) away from the roller arm (31) being connected to the drill bit body (1) through an elastic support ring (30), a rolling wheel (33) being rotatably arranged on the roller shaft (32), and a sealing assembly (6) being arranged between the roller shaft (32) and the rolling wheel (33); wherein the sealing assembly (6) comprises a first sealing member (61) and a second sealing member (62), the hardness of the first sealing member (61) being greater than that of the second sealing member (62), a seal being formed between the first sealing member (61) and the second sealing member (62), a dynamic seal being formed between the first sealing member (61) and the roller shaft (32), and a static seal being formed between the second sealing member (62) and the rolling wheel (33). A static seal is formed between the radially outer side of the first sealing member (61) and the radially outer side of the second sealing member (62).

2. The dual support PDC-roller hybrid drill bit of claim 1, wherein, The first sealing member (61) and the second sealing member (62) are of an integral structure.

3. The dual support PDC-roller hybrid drill bit of claim 1, wherein, The wear resistance of the first sealing member (61) is higher than that of the second sealing member (62).

4. The dual support PDC-roller hybrid drill bit of claim 1, wherein, The friction of the first sealing member (61) is lower than that of the second sealing member (62).

5. The dual support PDC-roller hybrid drill bit of claim 1, wherein, An oil tank (311) and an oil channel (312) are arranged in the roller arm (31), the oil channel (312) being configured to enable oil in the oil tank (311) to flow to the contact surface of the roller shaft (32) and the rolling wheel (33).

6. The dual support PDC-roller hybrid drill bit of any of claims 1-5, wherein, An oil cup (315) is arranged in the roller arm (31), the oil tank (311) being located in the oil cup (315), and a balance hole (314) is arranged in the roller arm (31) to communicate the oil cup (315) with the outside.

7. The dual support PDC-roller hybrid drill bit of claim 6, wherein, The balance hole (314) communicates the space between the rolling wheel (33) and the roller arm (31) with the oil cup (315).

8. The dual support PDC-roller hybrid drill bit of claim 7, wherein, An end of the oil cup (315) away from the balance hole (314) is provided with a first plug (316), the first plug (316) being provided with an oil injection hole (317) communicating with the inside of the oil tank (311).

9. The dual support PDC-roller hybrid drill bit of claim 8, wherein, Both axial ends of the roller shaft (32) protrude beyond the rolling wheel (33), one end of the roller shaft (32) is fixedly connected to the roller arm (31), an axle seat (35) is arranged on the PDC assembly (4), the other end of the roller shaft (32) is rotatably connected to the axle seat (35), and two sealing assemblies (6) are arranged at the axial ends of the roller shaft (32), respectively.

10. The dual support PDC-roller hybrid drill bit of any of claims 1-5, wherein, ​

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