Self-pressure flow channel pressurizing drill bit and drilling tool

Abstract

The invention belongs to the technical field of well drilling, and discloses a self-pressure flow channel pressurizing drill bit which comprises a drill bit body, a one-way valve and a pressurizing mechanism, a movable cavity, a pressurizing flow channel and a drilling fluid flow channel are formed in the drill bit body, an inlet and an outlet are further formed in the drill bit body, one end of the drilling fluid flow channel communicates with the inlet, and the other end of the drilling fluid flow channel communicates with the pressurizing flow channel; the other end of the pressurizing flow channel is communicated with the outlet; the one-way valve only allows drilling fluid to flow from the drilling fluid flow channel to the pressurizing flow channel; the pressurizing mechanism comprises a piston and a turbine, the turbine is arranged in the drilling fluid flow channel and can be pushed by drilling fluid to rotate, the piston is movably arranged in the pressurizing flow channel in a sealed mode, and the rotating motion of the turbine can be converted into the linear reciprocating motion of the piston. According to the self-pressure type flow channel pressurizing drill bit, the pressure generated when drilling fluid is sprayed out of the drill bit is effectively increased, then bit balling can be effectively prevented, rock debris on the crown of the drill bit body can be removed in time, the temperature of the drill bit body is reduced, and the service life is prolonged.

Description

Technical Field

[0001] This invention relates to the field of drilling technology, and more particularly to a self-pressurized flow channel booster drill bit and drilling tool. Background Technology

[0002] In drilling operations in deep and ultra-deep wells in hard formations, drill bits face three core problems: mud packing, cuttings accumulation, and cooling failure. These factors severely restrict rock-breaking efficiency and drill bit life, mainly manifested as follows:

[0003] 1. Drill bit mud bag problem

[0004] Clay particles and rock cuttings in drilling fluid easily adhere to the drill bit surface and flow channel inner wall under high temperature and pressure, forming a dense mud cake (i.e., mud bag). This causes the cutting teeth on the drill bit to be encased and the hydraulic channels to be blocked. Existing technologies mainly alleviate the mud bag problem by optimizing drilling fluid performance (such as adding inhibitors) or improving the drill bit surface coating. However, mud bagging still occurs frequently in highly abrasive formations. For example, if the flow channel between the cutter wings of a PDC drill bit is too narrow, mud bagging can easily cause a sharp drop in the effective flow area, leading to problems such as a sudden increase in drill bit torque and stagnation in drilling footage.

[0005] 2. Untimely removal of rock cuttings and repeated cutting

[0006] During drilling through hard formations, rock cuttings are hard and coarse. If they cannot be carried to the wellhead by the drilling fluid in time, they will accumulate at the bottom of the well and be further cut by the drill bit. Existing drill bit flow channel designs mostly rely on single hydraulic jetting or inefficient spiral cuttings removal structures, which are difficult to maintain stable cuttings removal efficiency under the high pressure environment of deep wells. For example, conventional conical flow channels, due to insufficient pressure gradient, tend to trap rock cuttings at the edge of the drill bit, causing repeated friction between the cutting teeth and the rock cuttings, accelerating tooth surface wear and reducing the mechanical drilling rate, significantly affecting drilling efficiency.

[0007] 3. Cooling failure and thermal damage

[0008] Cutting teeth generate significant frictional heat during rock breaking in hard formations. Deep well drilling fluids experience pressure decay due to long-distance transport, leading to reduced flow rates and insufficient cooling capacity. Current technologies primarily increase flow rates by increasing the number or diameter of nozzles; however, limited by wellbore size, excessive enlargement can weaken the drill bit's structural strength. Furthermore, mud buildup further exacerbates localized high temperatures, increasing the risk of thermal crack propagation in the cutting teeth and even causing interlayer delamination failure of the diamond composite sheet, severely impacting drill bit lifespan.

[0009] In summary, there is still considerable room for improvement in the adaptability of existing drill bits in deep and ultra-deep hard formations. There is an urgent need to innovate in areas such as flow channel optimization, cuttings removal, and cooling enhancement to improve rock breaking efficiency and drill bit durability. Summary of the Invention

[0010] The purpose of this invention is to provide a self-pressurized flow channel booster drill bit and drilling tool to solve problems such as drill bit mud packing, untimely removal of cuttings and repeated cutting, cooling failure and thermal damage.

[0011] To achieve this objective, the present invention adopts the following technical solution:

[0012] In a first aspect, the present invention provides a self-pressurized flow channel booster drill bit, comprising a drill bit body, cutting teeth, a one-way valve, and a booster mechanism. The drill bit body contains a movable cavity, a booster flow channel, and a drilling fluid flow channel. The drill bit body also has an inlet and an outlet. One end of the drilling fluid flow channel is connected to the inlet, and the other end is connected to the booster flow channel. One end of the booster flow channel is connected to the movable cavity, and the other end is connected to the outlet. The cutting teeth are disposed on the drill bit body. The one-way valve is disposed within the drilling fluid flow channel or the booster flow channel. The valve only allows drilling fluid to flow from the drilling fluid channel to the pressurization channel; the pressurization mechanism includes a piston, a transmission assembly, and a turbine. The turbine is disposed in the drilling fluid channel via a turbine shaft and can rotate under the push of the drilling fluid. The transmission assembly is disposed in the movable cavity. One end of the turbine shaft is inserted into the movable cavity and connected to the transmission assembly. The piston is movably disposed in the pressurization channel and connected to the turbine shaft via the transmission assembly to convert the rotational motion of the turbine into the linear reciprocating motion of the piston.

[0013] In one embodiment, the pressurization channel extends axially along the drill bit body.

[0014] In one embodiment, the axial direction of the turbine shaft is perpendicular to the extension direction of the booster channel. The transmission assembly includes a cam and a connecting rod. The cam is disposed on the turbine shaft and can rotate with the turbine shaft. One end of the connecting rod is rotatably connected to the cam, and the other end of the connecting rod is rotatably connected to the piston.

[0015] In one embodiment, the drill bit body is provided with multiple pressurization channels, and the outlet, the piston and the one-way valve are all provided in a one-to-one correspondence with the pressurization channels. The transmission assembly also includes a connecting plate, and each piston is vertically fixed on the connecting plate. The connecting rod is rotatably connected to the connecting plate.

[0016] In one embodiment, the movable cavity includes a first sub-cavity and a second sub-cavity. The cam is located in the first sub-cavity. One end of the connecting rod is connected to the cam, and the other end is inserted into the second sub-cavity and connected to the connecting plate. The outer periphery of the connecting plate is the same as the cross-sectional shape of the second sub-cavity.

[0017] In one embodiment, the piston includes a piston head and a piston rod, and the outer diameter of the piston head gradually increases from the end furthest from the outlet to the end closest to the outlet.

[0018] In one embodiment, the piston head is configured as a groove-shaped structure, with the groove of the piston head facing the outlet.

[0019] In one embodiment, the one-way valve includes a ball and an elastic element. The inner diameter of the drilling fluid flow channel gradually decreases from one end connected to the pressurization flow channel to the other end. The elastic element is disposed on the side of the ball facing away from the pressurization flow channel and is connected to the side wall of the drilling fluid flow channel.

[0020] In a second aspect, the present invention provides a drilling tool, including a drill pipe, and further including a self-pressurized flow channel booster drill bit as described in any of the preceding claims, the drill bit being connected to the drill pipe.

[0021] In one embodiment, the drill bit is threadedly connected to the drill rod.

[0022] The beneficial effects of this invention are:

[0023] The aforementioned self-pressurized flow channel booster drill bit features a booster flow channel within the drill bit body. Drilling fluid drives a turbine, which in turn drives a piston to reciprocate within the booster flow channel. When the piston moves away from the outlet, the pressure within the booster flow channel decreases, the check valve opens, and drilling fluid flows from the drilling fluid channel into the booster flow channel. When the piston moves closer to the outlet, the pressure within the booster flow channel increases, the check valve closes, and the drilling fluid is ejected from the outlet. The booster mechanism and booster flow channel effectively increase the pressure of the drilling fluid ejected from the drill bit, thereby effectively preventing mud buildup, promptly removing cuttings from the drill bit crown, preventing repeated cuttings breakage, reducing the temperature of the drill bit body, and improving the service life of the self-pressurized flow channel booster drill bit. It is worth emphasizing that when the pressurization channel and pressurization mechanism are located inside the drill bit, the drilling fluid sprays out of the outlet in a straight line after pressurization, and the distance traveled is short. Compared with setting the pressurization channel and pressurization mechanism on the short section connected to the drill bit, the pressurization efficiency of the drilling fluid is higher, the pressure loss is lower, and the effect of solving the above problems is better. Attached Figure Description

[0024] Figure 1 This is a three-dimensional structural schematic diagram of the self-pressurized flow channel booster drill bit in an embodiment of the present invention;

[0025] Figure 2 This is a top view of the self-pressurized flow channel booster drill bit in an embodiment of the present invention;

[0026] Figure 3 It is along Figure 2 Sectional view along the middle AA direction;

[0027] Figure 4 yes Figure 2 A sectional view along the BB direction;

[0028] Figure 5 This is a schematic diagram of the pressurization mechanism in an embodiment of the present invention;

[0029] Figure 6 This is a schematic diagram of the flow path of drilling fluid in a self-pressurized flow channel booster drill bit in an embodiment of the present invention.

[0030] In the picture:

[0031] 1. Drill bit body; 11. Inlet; 12. Outlet; 13. Moving chamber; 14. Pressure boosting channel; 15. Drilling fluid channel; 151. Main channel; 152. Branch channel; 2. Cutting teeth; 3. Pressure boosting mechanism; 31. Piston; 32. Turbine; 33. Transmission assembly; 331. Cam; 332. Connecting rod; 333. Connecting plate; 34. Turbine shaft; 4. Check valve; 41. Ball bearing; 42. Elastic element. Detailed Implementation

[0032] The present invention will now be described in further detail with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the invention and not intended to limit it. Furthermore, it should be noted that, for ease of description, the accompanying drawings show only the parts relevant to the present invention, and not all of the structures.

[0033] In the description of this invention, unless otherwise explicitly specified and limited, the terms "connected," "linked," and "fixed" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; 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; they can refer to the internal communication of two components or the interaction between two components. Those skilled in the art can understand the specific meaning of the above terms in this invention based on the specific circumstances.

[0034] In this invention, unless otherwise explicitly specified and limited, "above" or "below" the second feature can include direct contact between the first and second features, or contact between the first and second features through another feature between them. Furthermore, "above," "over," and "on top" of the second feature includes the first feature directly above or diagonally above the second feature, or simply indicates that the first feature is at a higher horizontal level than the second feature. "Below," "below," and "under" the second feature includes the first feature directly below or diagonally below the second feature, or simply indicates that the first feature is at a lower horizontal level than the second feature.

[0035] In the description of this embodiment, the terms "upper," "lower," "left," and "right," etc., refer to the orientation or positional relationship shown in the accompanying drawings. They are used only for ease of description and simplification of operation, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on the present invention. In addition, the terms "first" and "second" are used only for distinction in description and have no special meaning.

[0036] refer to Figures 1-6 As shown in the figure, this embodiment of the invention proposes a self-pressurized flow channel booster drill bit and drilling tool. The drilling tool includes a drill pipe and the aforementioned self-pressurized flow channel booster drill bit, which is connected to the drill pipe and can rotate under the drive of the drill pipe. The self-pressurized flow channel booster drill bit includes a drill bit body 1, cutting teeth 2, a booster mechanism 3, and a one-way valve 4. The cutting teeth 2 are disposed on the crown of the drill bit body 1. The shape and material of the cutting teeth 2 can be adapted to the actual drilling environment, and no specific limitation is made here. The drill bit body 1 is provided with a drilling fluid flow channel 15, a booster flow channel 14, and a movable cavity 13. At the same time, the drill bit body 1 is also provided with an inlet 11 and an outlet 12. The inlet 11 is used to communicate with the supply flow channel on the drill pipe for the flow of drilling fluid. One end of the drilling fluid flow channel 15 is connected to the inlet 11, and the other end is connected to the pressurization flow channel 14. One end of the pressurization flow channel 14 is connected to the movable chamber 13, and the other end is connected to the outlet 12. A one-way valve 4 is disposed in the drilling fluid flow channel 15 or the pressurization flow channel 14, and the one-way valve 4 only allows drilling fluid to flow from the drilling fluid flow channel 15 to the pressurization flow channel 14. The pressurization mechanism 3 includes a piston 31, a transmission assembly 33, and a turbine 32. The turbine 32 is rotatably disposed in the drilling fluid flow channel 15 via a turbine shaft 34 and can rotate under the push of the drilling fluid. The transmission assembly 33 is disposed in the movable chamber 13, and the turbine shaft 34 passes through the movable chamber 13 and is connected to the transmission assembly 33. The piston 31 is sealed and movably disposed in the pressurization flow channel 14 and is connected to the turbine shaft 34 via the transmission assembly 33. The transmission assembly 33 is used to convert the rotational motion of the turbine 32 into the linear reciprocating motion of the piston 31. It is worth noting that a seal is fitted at one end of the turbine shaft 34 that is inserted into the movable cavity 13 to prevent drilling fluid from flowing into the movable cavity 13 through the drilling fluid channel 15. At the same time, in order to reduce the friction between the turbine shaft 34 and the side wall of the booster channel 14 and the cavity wall of the movable cavity 13, a bearing is fitted on the turbine shaft 34.

[0037] The aforementioned self-pressurized flow channel booster drill bit has a booster flow channel 14 and a booster mechanism 3 installed inside the drill bit body 1. Drilling fluid drives a turbine 32 to rotate, which in turn drives a piston 31 to reciprocate within the booster flow channel 14. When the piston 31 moves away from the outlet 12, the pressure within the booster flow channel 14 decreases, the one-way valve 4 opens, and drilling fluid flows from the drilling fluid flow channel 15 into the booster flow channel 14. When the piston 31 moves closer to the outlet 12, the pressure within the booster flow channel 14 increases, the one-way valve 4 closes, and the drilling fluid is ejected from the outlet 12. The booster mechanism 3 and the booster flow channel 14 effectively increase the pressure of the drilling fluid ejected from the drill bit, thereby effectively preventing mud buildup on the drill bit, promptly removing cuttings from the crown of the drill bit body 1, preventing repeated breaking of cuttings, and simultaneously reducing the temperature of the drill bit body 1 and the cutting teeth 2 on the drill bit body 1. This improves the service life and drilling speed of the self-pressurized flow channel booster drill bit. It is worth emphasizing that the pressurization channel 14 and the pressurization mechanism 3 are located inside the drill bit body 1. Compared with the pressurization channel 14 and the pressurization mechanism 3 being located on the short section connected to the drill bit, the drilling fluid travels a shorter distance after being pressurized and ejected from the outlet 12, resulting in less pressure loss and higher ejection pressure, thus achieving a better effect in solving the above problems.

[0038] In some embodiments, the pressurization channel 14 extends axially along the drill bit body 1 to further reduce the path that the drilling fluid needs to take to exit from the pressurization channel 14 through the outlet 12, thereby further reducing the pressure loss of the drilling fluid.

[0039] Specifically, one end of the drill bit body 1 is provided with an external thread for detachable connection with the drill rod. Since the self-pressurized flow channel booster drill bit is a consumable part, it is designed to be connected to the drill rod by a thread for easy and timely replacement.

[0040] refer to Figure 3 As shown, the axial direction of the turbine shaft 34 is perpendicular to the direction of movement of the piston 31. Based on this, the transmission assembly 33 includes a cam 331 and a connecting rod 332. The cam 331 is mounted on the turbine shaft 34 and can rotate with the turbine shaft 34. One end of the connecting rod 332 is rotatably connected to the cam 331, and the other end is rotatably connected to the piston 31.

[0041] refer to Figures 4-6As shown, the drill bit body 1 is provided with multiple pressurized flow channels 14, and the outlet 12, piston 31, and one-way valve 4 are arranged one-to-one with the pressurized flow channels 14 to remove mud and cuttings from multiple angles and to cool the cutting teeth 2 from multiple angles. Specifically, the drill bit body 1 is provided with only one inlet 11, and the drilling fluid flow channel 15 includes a main flow channel 151 and multiple branch flow channels 152. The turbine 32 is disposed in the main flow channel 151, and one end of the branch flow channel 152 is connected to the main flow channel 151, and the other end is connected to the corresponding pressurized flow channel 14. More specifically, in order to make the drilling fluid pass through the turbine 32 as much as possible and thus make full use of the drilling fluid kinetic energy, the main flow channel 151 includes a mounting cavity, and the turbine 32 is disposed in the mounting cavity. The width of the mounting cavity along the axial direction of the turbine 32 is as consistent as possible with the axial length of the turbine 32, and the width of the mounting cavity along the radial direction of the turbine 32 is also as consistent as possible with the radial length of the turbine 32. For example, the cross-section of the mounting cavity is set to be circular.

[0042] Given that there are multiple pistons 31, the transmission assembly 33 also includes a connecting plate 333. The piston 31 is vertically fixed on the connecting plate 333, and the connecting rod 332 is rotatably connected to the connecting plate 333 to achieve rotatable connection with the piston 31. That is, multiple pistons 31 are driven by the same turbine 32. The entire pressurization mechanism 3 has a simple structure and the manufacturing cost of the self-pressurized flow channel pressurization drill bit is low.

[0043] refer to Figure 5 As shown, piston 31 includes piston head and piston rod. The longitudinal section of piston head is trapezoidal, and its outer diameter gradually increases from the end away from outlet 12 to the end closer to outlet 12. Since the end face area of ​​piston head near outlet 12 is larger than that of end face away from outlet 12, when piston moves towards outlet 12, the end of piston head near outlet 12 expands outward, and it fits more tightly with the side wall of pressurized flow channel 14, ensuring that drilling fluid can flow out from pressurized flow channel 14. When piston 31 moves away from outlet 12, the end of piston head near outlet 12 retracts inward, and the friction between it and the side wall of pressurized flow channel 14 decreases, reducing the force required for retraction.

[0044] More specifically, the piston head is configured as a groove-shaped structure with its groove opening facing the outlet 12.

[0045] In order to limit the movement direction of the connecting plate 333 and make the connecting plate 333 move in a straight line, thereby causing the piston 31 to move along the extension direction of the pressurization channel 14, the movable cavity 13 includes a first sub-cavity and a second sub-cavity, wherein the cam 331 is located in the first sub-cavity, one end of the connecting rod 332 is located in the first sub-cavity to connect the cam 331, and the other end is inserted into the second sub-cavity to connect with the connecting plate 333. The outer peripheral contour shape of the connecting plate 333 is the same as the cross-sectional shape of the second sub-cavity.

[0046] refer to Figure 4 As shown, the one-way valve 4 includes a ball 41 and an elastic element 42. The drilling fluid flow channel 15 gradually narrows in diameter from one end connected to the pressurization flow channel 14 to the other end. The elastic element 42 is located on the side of the ball 41 facing away from the pressurization flow channel 14 and is connected to the side wall of the drilling fluid flow channel 15. When the piston 31 moves towards the outlet 12, the drilling fluid pushes the ball 41 to move away from the pressurization flow channel 14, allowing the ball 41 to completely fit against the inner side wall of the drilling fluid flow channel 15. This prevents drilling fluid from flowing from the pressurized flow channel 14 to the drilling fluid flow channel 15. During this process, the elastic element 42 is compressed. When the piston 31 moves away from the outlet 12, a negative pressure is formed on the side of the pressurized flow channel 14 connected to the outlet 12. Under the elastic force of the elastic element 42, the ball 41 moves towards the pressurized flow channel 14. A gap is formed between the ball 41 and the side wall of the drilling fluid flow channel 15 for the drilling fluid to pass through. The drilling fluid enters the pressurized flow channel 14 through the drilling fluid flow channel.

[0047] Obviously, the above embodiments of the present invention are merely examples for clearly illustrating the present invention, and are not intended to limit the implementation of the present invention. Those skilled in the art will be able to make various obvious changes, readjustments, and substitutions without departing from the scope of protection of the present invention. It is neither necessary nor possible to exhaustively describe all embodiments here. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present invention should be included within the scope of protection of the claims of the present invention.

Claims

1. A self-pressurized flow channel booster drill bit, characterized in that, include: The drill bit body (1) has an internal movable cavity (13), a pressurized flow channel (14) and a drilling fluid flow channel (15). The drill bit body (1) also has an inlet (11) and an outlet (12). One end of the drilling fluid flow channel (15) is connected to the inlet (11) and the other end is connected to the pressurized flow channel (14). One end of the pressurized flow channel (14) is connected to the movable cavity (13) and the other end is connected to the outlet (12). Cutting teeth (2) are provided on the drill bit body (1); A one-way valve (4) is provided in the drilling fluid flow channel (15) or the pressurization flow channel (14). The one-way valve (4) only allows drilling fluid to flow from the drilling fluid flow channel (15) to the pressurization flow channel (14). The boosting mechanism (3) includes a piston (31), a transmission assembly (33), and a turbine (32). The turbine (32) is disposed in the drilling fluid flow channel (15) via a turbine shaft (34) and can rotate under the push of the drilling fluid. The transmission assembly (33) is disposed in the movable cavity (13). One end of the turbine shaft (34) is inserted into the movable cavity (13) and connected to the transmission assembly (33). The piston (31) is disposed in the boosting flow channel (14) and connected to the turbine shaft (34) via the transmission assembly (33) to convert the rotational motion of the turbine (32) into the linear reciprocating motion of the piston (31).

2. The self-pressurized flow channel booster drill bit according to claim 1, characterized in that, The pressurization channel (14) extends along the axial direction of the drill bit body (1).

3. The self-pressurized flow channel booster drill bit according to claim 2, characterized in that, The axial direction of the turbine shaft (34) is perpendicular to the extension direction of the booster channel (14). The transmission assembly (33) includes a cam (331) and a connecting rod (332). The cam (331) is disposed on the turbine shaft (34) and can rotate with the turbine shaft (34). One end of the connecting rod (332) is rotatably connected to the cam (331), and the other end of the connecting rod (332) is rotatably connected to the piston (31).

4. The self-pressurized flow channel booster drill bit according to claim 3, characterized in that, The drill bit body (1) is provided with multiple pressurization channels (14). The outlet (12), the piston (31) and the one-way valve (4) are all provided in correspondence with the pressurization channels (14). The transmission assembly (33) also includes a connecting plate (333). Each piston (31) is vertically fixed on the connecting plate (333). The connecting rod (332) is rotatably connected to the connecting plate (333).

5. The self-pressurized flow channel booster drill bit according to claim 4, characterized in that, The active cavity (13) includes a first sub-cavity and a second sub-cavity. The cam (331) is located in the first sub-cavity. One end of the connecting rod (332) is connected to the cam (331), and the other end is inserted into the second sub-cavity and connected to the connecting plate (333). The outer periphery contour shape of the connecting plate (333) is the same as the cross-sectional shape of the second sub-cavity.

6. The self-pressurized flow channel booster drill bit according to any one of claims 1-5, characterized in that, The piston (31) includes a piston head and a piston rod, and the outer diameter of the piston head gradually increases from the end away from the outlet (12) to the end closer to the outlet (12).

7. The self-pressurized flow channel booster drill bit according to claim 6, characterized in that, The piston head is configured as a groove structure, and the groove of the piston head is positioned facing the outlet (12).

8. The self-pressurized flow channel booster drill bit according to any one of claims 1-5, characterized in that, The one-way valve (4) includes a ball (41) and an elastic element (42). The inner diameter of the drilling fluid flow channel (15) gradually decreases from one end connected to the pressurization flow channel (14) to the other end. The elastic element (42) is disposed on the side of the ball (41) facing away from the pressurization flow channel (14) and is connected to the side wall of the drilling fluid flow channel (15).

9. A drilling tool, including drill pipe, characterized in that, It also includes a self-pressurized flow channel booster drill bit as described in any one of claims 1-8, the drill bit being connected to the drill rod.

10. The drilling tool according to claim 9, characterized in that, The drill bit is threadedly connected to the drill rod.

Images