A screw drilling tool with a multifunctional bypass valve

Abstract

The present invention discloses a screw drill with a multifunctional bypass valve, comprising a motor assembly, a universal shaft assembly and a transmission shaft assembly which are detachably installed in sequence, and a bypass valve assembly installed above the motor assembly, wherein the hydraulic valve has two telescopic valve plugs penetrating the housing, and a hydraulic flow channel which drives the two telescopic valve plugs to move relative to each other by hydraulic pressure, and drives the opening and closing of the hydraulic valve when the internal and external hydraulic pressure difference of the bypass valve assembly changes. In the present invention, a combination of a movable valve core and a hydraulic valve is adopted, and the working environment of the screw drill can be judged by itself and corresponding judgments and actions can be made, which effectively reduces the problem that the types of faults that are difficult to detect and the corresponding remedial and anti-damage measures are not easy to make when the screw drill is operating underground.

Description

Technical Field

[0001] The invention belongs to the technical field of screw drill tools, in particular to a screw drill tool with a multifunctional bypass valve. Background Art

[0002] Screw drilling tools are volumetric downhole power motors powered by drilling fluid. They use the pressure difference formed when the drilling fluid pumped out of the drilling pump flows through the inlet and outlet of the motor to drive the motor's rotor to rotate, and drive the drill bit to rotate through its internal universal joint and transmission shaft, converting the hydraulic power composed of the drilling fluid pressure difference and flow into mechanical power composed of torque and speed that drives the drill bit to rotate, thus becoming a downhole power drilling tool that only drives the drill bit to rotate.

[0003] Screw drill tools are roughly divided into the following categories according to different usage scenarios: screw drill tools for drilling; screw drill tools for oil production and well repair; screw drill tools for surface crossing and screw drill tools for underground gas layers, etc. Their working principles are exactly the same, but there are great differences in structure and strength.

[0004] The most basic components of screw drilling tools are the bypass valve, motor, universal shaft and drive shaft. In order to meet the needs of directional wells or other drilling projects, other components such as directional joints, bent joints, universal shaft fixed bent housings (fixed angles between 0 and 3°), universal shaft ground adjustable bent housings, drive shaft stabilizers, and removable stabilizers can be added or replaced to form various forms of screw drilling tools.

[0005] Among them, the bypass valve of the screw drill is mainly used to balance the pressure difference between the inside and outside of the drill. It is mainly composed of valve body, valve sleeve, valve core and spring. During the drilling operation, the bypass valve allows the drilling fluid to balance the pressure difference between the inside and outside of the drill through the bypass hole. Specifically, when drilling, the drilling fluid in the annulus is allowed to flow into the drill string through the bypass hole to reduce the resistance of drilling; when drilling, the drilling fluid in the drill string is allowed to flow out of the bypass hole into the annulus to prevent the mud from overflowing on the well platform. During drilling, under the action of high-pressure drilling fluid, the bypass valve is closed, so that all drilling fluid flows through the motor and converts pressure energy into mechanical energy. In addition, the bypass valve also has the functions of preventing liquid backflow, preventing drill cuttings from jamming the drill, preventing accidental blowouts, and leaking the well washing fluid in the drill string.

[0006] However, since the working environment of the screw drill is relatively harsh and is generally located in a high-pressure and high-temperature underground environment, it is difficult to understand specifically what faults have occurred during the operation process. Therefore, the bypass valve can generally only perform explosion-proof work, that is, when the pressure in the screw drill is too high, the bypass valve is automatically opened to prevent the screw drill from bursting. For example, in the prior art - a pressure relief method and device for a screw drill bypass valve (publication number CN113982512A), a Chinese invention patent records a pressure relief method and device for a screw drill bypass valve, the device includes a valve body and a pressure relief mechanism; the pressure relief mechanism can reduce the pressure of the drilling fluid in the first guide chamber, thereby preventing the flow rate of the drilling fluid entering the motor assembly from exceeding the maximum allowable value and causing damage to the motor assembly; however, for different causes of failure, the bypass valves in the prior art all use the same processing method - opening the bypass valve to make the inside and outside of the device equal.

[0007] However, in the actual production process, there are also factors such as leakage of the hydraulic pressure supply pipeline of the screw drill and encountering underground cavities, which cause the hydraulic pressure difference between the inside and outside of the screw drill. When the hydraulic pressure supply pipeline leaks, opening the bypass valve will cause the underground high-pressure liquid to flow into the device and cause pollution. Opening the bypass valve in the underground cavity will cause the problem of leakage first and then backflow. Therefore, the existing bypass valve still has various defects in actual use. Summary of the invention

[0008] The purpose of the present invention is to address the problem that it is difficult to judge the cause of the failure of the screw drill by itself when the bypass valve of the existing screw drill is in use, and to adopt the same solution method of opening the bypass valve to solve the problem that opening the bypass valve in an inappropriate scenario will cause greater losses. A hydraulic valve with a more complicated judgment scenario is combined with the existing bypass valve, so that the opening and closing of the bypass valve is more suitable for the use scenario of the screw drill, and a screw drill with a multifunctional bypass valve is provided.

[0009] The technical solution adopted by the present invention is as follows:

[0010] A screw drill with a multifunctional bypass valve comprises a motor assembly, a universal shaft assembly and a transmission shaft assembly which are detachably mounted in sequence, and also comprises a bypass valve assembly mounted above the motor assembly, wherein the bypass valve assembly comprises:

[0011] A valve housing, a fixed plug movably mounted from bottom to top in the inner cavity of the valve housing, and a valve core movably mounted from top to bottom in the inner cavity of the fixed plug; a plurality of hydraulic valves mounted between the inner and outer walls of the valve housing, and a spring assembly arranged between the fixed plug and the valve core;

[0012] The valve housing comprises an outer shell which is connected with each other from top to bottom, and a bypass hole which passes through both sides of the outer shell, and the plurality of hydraulic valves are installed in the bypass holes in a one-to-one correspondence;

[0013] The hydraulic valve has two telescopic valve plugs penetrating the housing, and a hydraulic flow channel that drives the two telescopic valve plugs to move relative to each other through hydraulic pressure, and drives the opening and closing of the hydraulic valve when the internal and external hydraulic pressure difference of the bypass valve assembly changes.

[0014] Among them, the bypass hole includes: two bypass valve main holes coaxially arranged on both sides of the inner and outer sides of the shell, the two telescopic valve plugs are respectively inserted into the inner cavities of the two bypass valve main holes, a spring groove flow channel and a bypass valve flow channel are connected between the two bypass valve main holes, the spring groove flow channel is connected to the inner cavity of the shell through the hydraulic groove flow channel, the inner cavity of the hydraulic groove flow channel is slidably connected with a piston, and the hydraulic groove flow channel and the spring groove flow channel are filled with hydraulic medium with a pressure exceeding atmospheric pressure.

[0015] Among them, the two telescopic valve plugs in the hydraulic valve are arranged in opposite directions, and the sides of the two telescopic valve plugs close to each other are connected with a side pipe matching the bypass valve flow channel and a main pipe matching the spring groove flow channel, and a side pipe hole penetrating inside and outside is opened at the connection between the side pipe and the telescopic valve plug, and a clamping ring structure is formed at the opening of the main pipe in a radially outward protrusion, and a first compression spring is wrapped around the outside of the main pipe, and the two ends of the first compression spring are respectively abutted against the clamping ring structure and the side wall of the hydraulic groove flow channel.

[0016] Among them, in the bypass hole, there are set a spring groove flow channel and at least two bypass valve flow channels arranged in a ring equidistantly around the central axis of the spring groove flow channel, and an annular flow channel is also connected between the hydraulic groove flow channel and the spring groove flow channel, and multiple straight flow channels and multiple curved flow channels are connected between the annular flow channel and the spring groove flow channel, and guide flow channels are respectively connected between the annular flow channel and the hydraulic groove flow channel.

[0017] Wherein, in the bypass hole, an annular flow channel arranged in an annular pipe shape is connected with a plurality of hydraulic groove flow channels, and a plurality of the straight flow channels correspond one to one with a plurality of the curved flow channels.

[0018] Among them, the valve shell has an annular contraction hole formed by the inward contraction of the inner wall of the shell, the top of the shell is provided with an upper threaded joint, the upper threaded joint is set as an internal thread structure, and the bottom of the shell is provided with a lower threaded joint, the lower threaded joint is set as an external thread structure.

[0019] Among them, the fixed plug has a plug body that is movably arranged in the inner cavity of the shell, the top end of the plug body abuts against the annular shrinkage hole, the plug body is formed into a cylindrical structure that can slide against the inner wall of the shell, and the bottom end of the cylindrical structure shrinks inward to form an annular portion, and the cylindrical structure is also provided with a plug hole that connects the inside and the outside above the annular portion.

[0020] Among them, the valve core has a valve body core seat movably arranged in the inner cavity of the plug body, the top of the valve body core seat is abutted against the annular contraction hole, the outer wall of the valve body core seat fits and slides with the inner wall of the plug body, the bottom end of the valve body core seat is connected to a valve body core rod which is inserted and slid with the annular part, and the valve body core rod is provided with a valve body core hole which is connected inside and outside.

[0021] Wherein, the spring assembly has a second compression spring arranged in the gap between the valve body core seat and the plug body, one end of the second compression spring abuts against the valve body core seat, and the other end abuts against the top end of the annular portion.

[0022] The plug holes are arranged to correspond one to one with the hydraulic valves, and a protruding plug which cooperates with the plug holes to abut and seal is arranged on the outer side of one of the two telescopic valve plugs in the hydraulic valve.

[0023] In summary, due to the adoption of the above technical solution, the beneficial effects of the present invention are:

[0024] 1. In the present invention, a movable valve core and a hydraulic valve are used in combination. During the process of lowering the device into the well, the hydraulic valve is opened by its own hydraulic pressure, and the valve core is closed. On the one hand, the inner cavity of the valve housing can be filled with liquid in the clear section underground, which reduces the buoyancy and increases the stability of the device entering the well. At the same time, the fit between the protruding plug and the plug hole isolates the liquid environment inside and outside the fixed plug, preventing impurities in the underground liquid from entering the innermost side of the device.

[0025] When the device is lowered into the well to the working section, the hydraulic valve is automatically closed due to the high pressure environment in the well, and the hydraulic pressure difference generated at the valve core by the liquid supply pipeline closes the valve core, thereby forming a synchronous closure of the two devices to avoid the possibility of leakage;

[0026] When the device fails, the internal and external connections at the valve core are restored by the disappearance of the hydraulic pressure difference, and the opening and closing of the hydraulic valve are automatically adjusted according to the hydraulic pressure difference between the inside and outside of the valve housing; when the hydraulic pressure inside the valve housing is greater than the downhole pressure, the hydraulic valve can be pushed to open inside and outside to relieve pressure and prevent explosion; when the hydraulic pressure inside the valve housing is less than the downhole pressure, it indicates that the pipeline providing pressure is faulty. At this time, avoid opening the hydraulic valve to prevent external impurities from flowing into the valve housing and causing pollution;

[0027] The above-mentioned various action states do not require additional remote sensing or control components to be implemented. The working environment of the screw drill can be judged by itself and corresponding judgments and actions can be made, which effectively reduces the problem that the screw drill is difficult to detect fault types and difficult to make corresponding remedial and loss prevention measures when operating underground. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] Figure 1 It is a schematic diagram of the main structure of the bypass valve assembly in the screw drilling tool of the present invention;

[0029] Figure 2 Schematic diagram of the external structure of the bypass valve assembly in the present invention;

[0030] Figure 3 A schematic diagram of the vertical cross-sectional structure at the center of the bypass valve assembly in the present invention (the left and right sides are respectively the effects of the cross-sectional structure after being filled and not filled);

[0031] Figure 4 For the present invention Figure 3 Enlarged view of point A in the middle;

[0032] Figure 5 It is a schematic diagram of the broken line cross-section structure of the bypass valve assembly in the present invention;

[0033] Figure 6 For the present invention Figure 5 Enlarged view of point B in the middle;

[0034] Figure 7 For the present invention Figure 6 Enlarged view of point C in the middle;

[0035] Figure 8 Schematic diagram of three cross-section structures of the bypass valve assembly of the present invention (without filling effect);

[0036] Fig. 9 For the present invention Figure 8 Enlarged view of point D in the middle;

[0037] Fig.10 It is a schematic diagram of the vertical cross-sectional structure of the main pipeline of the bypass valve assembly in the present invention;

[0038] Fig.11 For the present invention Fig.10 Enlarged view of point E in the middle;

[0039] Fig.12 It is a schematic diagram of the cross-sectional structure of the hydraulic groove flow channel of the bypass valve assembly in the present invention;

[0040] Fig.13 For the present invention Fig.12 Enlarged view of point F in the middle.

[0041] Markings in the figure: 1, valve housing; 11, outer shell; 12, bypass valve main hole; 13, lower threaded joint; 14, upper threaded joint; 15, contraction hole;

[0042] 2. Fixed plug; 21. Plug body; 22. Plug hole;

[0043] 3. Valve core; 31. Valve body core seat; 32. Valve body core rod; 33. Valve body core hole;

[0044] 4. Hydraulic valve; 41. Telescopic valve plug; 411. Side pipeline; 412. Side pipe hole; 413. Main pipeline; 414. First compression spring; 415. Protruding plug;

[0045] 42, hydraulic flow channel; 421, straight flow channel; 422, curved flow channel; 423, annular flow channel; 424, spring groove flow channel; 425, guide flow channel; 426, hydraulic groove flow channel; 427, piston; 428, bypass valve flow channel;

[0046] 5. Spring assembly; 51. Second compression spring. DETAILED DESCRIPTION

[0047] In order to make the purpose, technical solution and advantages of the present invention more clearly understood, the present invention is further described in detail below in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not used to limit the present invention.

[0048] Embodiment 1, refer to Figure 1-Figure 13 , a screw drill with a multifunctional bypass valve, comprising a motor assembly, a universal shaft assembly and a transmission shaft assembly which are detachably installed in sequence, and also comprising a bypass valve assembly installed above the motor assembly, wherein the bypass valve assembly is arranged at the top of the overall device and is connected to an external hydraulic pipeline. When in use, hydraulic medium is filled into the motor assembly through the bypass valve assembly, so that the motor assembly starts to rotate under the driving of the inconsistent hydraulic pressure difference between the upper and lower parts, thereby driving the rotation of the universal shaft assembly and the transmission shaft assembly, wherein the setting of the universal shaft assembly is used to transmit the rotation effect of the motor assembly to the transmission shaft assembly, and the axial direction of the input end and the output end of the universal shaft assembly is adjustable, that is, the rotation axes of the motor assembly and the transmission shaft assembly can be arranged non-coincidentally; the setting of the transmission shaft assembly is used to install an external drill bit to the bottom output end of the transmission shaft assembly, and at the same time, the hydraulic medium input at the top bypass valve assembly can also flow out of the device cavity from the transmission shaft assembly;

[0049] The bypass valve assembly comprises: a valve housing 1, a fixed plug 2 movably mounted from bottom to top in the inner cavity of the valve housing 1, and a valve core 3 movably mounted from top to bottom in the inner cavity of the fixed plug 2; a plurality of hydraulic valves 4 mounted between the inner and outer walls of the valve housing 1, and a spring assembly 5 arranged between the fixed plug 2 and the valve core 3;

[0050] Furthermore, the valve housing 1 has an annular contraction hole 15 formed by the inner wall of the outer shell 11 contracting inwardly, an upper threaded joint 14 is provided at the top of the outer shell 11, and the upper threaded joint 14 is provided as an internal thread structure, and a lower threaded joint 13 is provided at the bottom of the outer shell 11, and the lower threaded joint 13 is provided as an external thread structure; the fixed plug 2 has a plug body 21 movably provided in the inner cavity of the outer shell 11, and the top of the plug body 21 abuts against the annular contraction hole 15, and the plug body 21 is formed to fit the inner wall of the outer shell 11 and can slide. The cylindrical structure has a bottom end that contracts inwardly to form an annular portion, and a plug hole 22 communicating with the inside and outside is also provided above the annular portion of the cylindrical structure; the valve core 3 has a valve core seat 31 that is movably arranged in the inner cavity of the plug body 21, the top of the valve core seat 31 abuts against the annular contraction hole 15, the outer wall of the valve core seat 31 fits and slides with the inner wall of the plug body 21, the bottom end of the valve core seat 31 is connected to a valve core rod 32 that is inserted and slid with the annular portion, and a valve core hole 33 communicating with the inside and outside is opened at the valve core rod 32;

[0051] During installation, the valve core 3 is inserted into the interior of the fixed plug 2 from the top opening of the fixed plug 2, and the spring assembly 5 is placed in the gap between the valve core 3 and the fixed plug 2. Then, the fixed plug 2 and the valve core 3 are simultaneously slid into the inner cavity of the valve housing 1 from the bottom opening of the valve housing 1, and the fixed plug 2 is fixed inside the valve housing 1 using a clamping ring;

[0052] That is, the top of the plug body 21 and the top of the valve body core seat 31 are both in contact with the bottom of the contraction hole 15, the valve body core rod 32 is connected with the inner cavity of the plug body 21 through the valve body core hole 33, and the plug body 21 is connected with the inner cavity of the shell 11 through the plug hole 22; when the valve body core rod 32 is affected by the hydraulic pressure difference and resists the elastic force of the second compression spring 51 to move downward, the valve body core hole 33 can be moved to the annular part of the fixed plug 2 and closed.

[0053] When in use, when hydraulic medium is filled into the inner cavity of the valve housing 1 through an external hydraulic pipeline, since the inner cavity aperture of the valve core 3 is smaller than the aperture of the outer shell 11, a hydraulic pressure difference and a flow rate difference will be generated at the upper and lower ends of the valve core 3. Then, the hydraulic pressure difference generated at the upper and lower ends of the valve core 3 can push the valve core 3 to squeeze the spring assembly 5, and the connection between the valve core 3 and the fixed plug 2 is blocked by the fixed plug 2, thereby disconnecting the bypass valve assembly from the flow channel outside the device; when the device is operating normally, the bypass valve assembly is closed to reduce the leakage of hydraulic medium;

[0054] When the hydraulic passage below the device is blocked and cannot flow out normally, the hydraulic flow rate at the valve core 3 is reduced, and the hydraulic differential thrust on the valve core 3 disappears, so that the valve core 3 no longer has the compression effect on the spring assembly 5. At this time, the valve core 3 is pushed by the spring assembly 5 to reset to the initial state, so that the flow channel between the valve core 3 and the fixed plug 2 can be restored to communication, so that the bypass valve assembly can be automatically opened to release pressure when the motor assembly or the transmission shaft assembly is stuck, so as to avoid the device from bursting due to excessive internal pressure;

[0055] The valve housing 1 has an outer shell 11 connected up and down, and a bypass hole penetrating both sides of the outer shell 11, and a plurality of hydraulic valves 4 are installed in the bypass holes in a one-to-one correspondence; the hydraulic valve 4 has two telescopic valve plugs 41 penetrating the outer shell 11, and a hydraulic flow channel 42 that drives the two telescopic valve plugs 41 to move relative to each other through hydraulic pressure, and drives the hydraulic valve 4 to be opened and closed when the internal and external hydraulic pressure difference of the bypass valve assembly changes;

[0056] In the initial state, the hydraulic medium filled in the inner cavity of the hydraulic flow channel 42 makes the two telescopic valve plugs 41 have a hydraulic thrust exceeding the atmospheric pressure. When the valve housing 1 is under the atmospheric pressure outside the drilling well, since the outer side of the telescopic valve plug 41 is only affected by the atmospheric pressure, the hydraulic medium in the inner cavity of the hydraulic flow channel 42 can push the two telescopic valve plugs 41 apart from each other. Therefore, the hydraulic valve 4 is in an open state under atmospheric pressure.

[0057] When the whole device is extended from the upper end of the well into the well, the process is divided into a clear liquid section above the well and a turbid section near the bottom of the well; when the device moves downward in the clear liquid section, the bypass hole is opened by the internal pressure of the hydraulic valve 4, so that the liquid in the well can flow into the inner cavity of the valve housing 1 from the bypass hole until the hydraulic pressure inside and outside the valve housing 1 is consistent, and at the same time, the air in the inner cavity of the valve housing 1 is emptied to reduce the air in the inner cavity of the valve housing 1 and further reduce the buoyancy of the valve housing 1, so as to achieve stable and rapid sinking of the valve housing 1;

[0058] When the whole device falls into the well to a sufficient depth (the pressure drop inside and outside the hydraulic valve 4 is ≥7.0MPa and ≤14.0MPa), the hydraulic thrust in the hydraulic flow channel 42 can no longer support the two telescopic valve plugs 41 to spread apart from each other. Due to the sufficiently high hydraulic pressure in the well, the two telescopic valve plugs 41 approach each other and block the bypass hole originally connected to the inside and outside of the housing 11; at the same time, the valve body core rod 32 is pressed down and the channel connecting the inside and outside of the valve body core rod 32 is blocked by the hydraulic pressure difference between the upper and lower sides of the valve body core rod 32, that is, when the whole device is operating normally, the hydraulic valves 4 are closed to each other, and the channels inside and outside the valve body core rod 32 are also blocked. When the whole device is operating normally, the inside and outside of the valve housing 1 are highly closed to avoid leakage and the bypass hole being stuck by foreign objects;

[0059] When the device fails during underground operation, for example, the outlet of the transmission shaft assembly is blocked, resulting in the gradual increase of hydraulic pressure in the entire device and the failure to release the hydraulic pressure. At this time, since the hydraulic medium no longer flows out, the upper and lower sides of the valve core 3 are no longer subject to the hydraulic pressure difference, so that the spring assembly 5 pushes the valve core 3 to move upward until it is reset, and the inner and outer sides of the valve core 3 are connected, guiding the hydraulic medium to the hydraulic valve 4;

[0060] The gradually increasing hydraulic pressure in the inner cavity of the valve housing 1 causes the hydraulic flow channel 42 to be subjected to the hydraulic thrust of the inner cavity of the valve housing 1, and causes the movable components in the hydraulic flow channel 42 to move inward, squeezing the inner space of the hydraulic flow channel 42 until the hydraulic pressure of the hydraulic flow channel 42 pushes open the telescopic valve plug 41 inside the valve housing 1, thereby allowing the hydraulic medium blocked in the inner cavity of the valve housing 1 to flow into the bypass hole between the two telescopic valve plugs 41;

[0061] At this time, if the hydraulic pressure between the two telescopic valve plugs 41 is greater than the downhole pressure outside the device, the telescopic valve plug 41 outside the valve housing 1 is pushed open, so that the hydraulic medium blocked in the inner cavity of the valve housing 1 is released from the bypass hole, thereby preventing the valve housing 1 from bursting due to excessive hydraulic pressure in the inner cavity;

[0062] If the hydraulic pressure between the two telescopic valve plugs 41 is less than the downhole pressure outside the device, it means that the external hydraulic pressure of the valve housing 1 is greater than the blocked hydraulic pressure inside, or the pipeline that provides the hydraulic medium to the valve housing 1 is broken, resulting in insufficient hydraulic pressure, which means that the bypass valve should not be opened at this time to cause external downhole sewage to flow into the pipeline. Therefore, the telescopic valve plug 41 outside the valve housing 1 is always closed to prevent external downhole sewage from flowing in.

[0063] Finally, when the device completes the operation and leaves the drilling well, the external hydraulic pressure of the device decreases when approaching the wellhead, so that the two telescopic valve plugs 41 can be stretched open by the hydraulic pressure inside the hydraulic channel 42, thereby facilitating the hydraulic medium in the device to flow out of the inner cavity of the valve housing 1, thereby avoiding the injection and contamination of the high-pressure liquid medium in the inner cavity of the valve housing 1 when drilling.

[0064] Furthermore, the bypass hole includes: two bypass valve main holes 12 respectively opened on both sides of the outer shell 11 and coaxially arranged, two telescopic valve plugs 41 are respectively inserted into the inner cavities of the two bypass valve main holes 12, a spring groove flow channel 424 and a bypass valve flow channel 428 are connected between the two bypass valve main holes 12, the spring groove flow channel 424 is connected to the inner cavity of the shell 11 through a hydraulic groove flow channel 426, a piston 427 is slidably connected to the inner cavity of the hydraulic groove flow channel 426, and the hydraulic groove flow channel 426 and the spring groove flow channel 424 are filled with hydraulic medium with a pressure exceeding atmospheric pressure; the two telescopic valve plugs 41 in the hydraulic valve 4 are arranged in opposite directions, and the sides of the two telescopic valve plugs 41 close to each other are connected with a side pipe 411 matching the bypass valve flow channel 428 and a main pipe 413 matching the spring groove flow channel 424, and a side pipe hole 412 penetrating inside and outside is opened at the connection between the side pipe 411 and the telescopic valve plug 41. , a snap ring structure is formed at the radially outward protrusion of the opening of the main pipeline 413, a first compression spring 414 is wound around the outside of the main pipeline 413, and the two ends of the first compression spring 414 are respectively in contact with the snap ring structure and the side wall of the hydraulic groove flow channel 426; in the bypass hole, a spring groove flow channel 424 and at least two bypass valve flow channels 428 arranged in an annular manner equidistantly around the central axis of the spring groove flow channel 424 are provided, and an annular flow channel 423 is also connected between the hydraulic groove flow channel 426 and the spring groove flow channel 424, and a plurality of straight flow channels 421 and a plurality of curved flow channels 422 are connected between the annular flow channel 423 and the spring groove flow channel 424, and guide flow channels 425 are respectively connected between the annular flow channel 423 and the hydraulic groove flow channel 426; in the bypass hole, the annular flow channel 423 set in the shape of an annular pipeline is connected with a plurality of hydraulic groove flow channels 426, and a plurality of straight flow channels 421 correspond to a plurality of curved flow channels 422 one by one;

[0065] The two bypass valve main holes 12 are provided to make the inner and outer telescopic valve plugs 41 sink into the two bypass valve main holes 12 when they are closed, thereby reducing the collision of the mud in the well with the two telescopic valve plugs 41;

[0066] The arrangement of the spring groove flow channel 424 enables the spring groove flow channel 424, the straight flow channel 421, the curved flow channel 422, the annular flow channel 423, the guide flow channel 425 and the hydraulic groove flow channel 426, which are connected to each other in sequence, to form a complete hydraulic pipeline body, and is isolated from the external environment by the piston 427, and does not have any liquid communication with any external environment. It is only pushed when the internal and external hydraulic environments meet sufficient conditions, so that the bypass hole is opened to circulate the internal and external liquids;

[0067] The bypass valve channel 428 is only used to further make the bypass hole have the effect of internal and external connection when the two telescopic valve plugs 41 move away from each other, so that the side pipe hole 412 damaged by the side pipe 411 moves to the outside of the bypass valve channel 428. In other states, the bypass hole channel cannot be opened when only one of the two telescopic valve plugs 41 is pushed open.

[0068] Furthermore, the spring assembly 5 has a second compression spring 51 disposed at the gap between the valve body core seat 31 and the plug body 21, one end of the second compression spring 51 abuts against the valve body core seat 31, and the other end abuts against the top of the annular portion; the plug hole 22 is arranged to correspond to the hydraulic valve 4 one by one, and a protruding plug 415 that cooperates with the plug hole 22 to abut and seal is arranged on the outer side of one of the two telescopic valve plugs 41 in the hydraulic valve 4;

[0069] Among them, when the protruding plug 415 on the telescopic valve plug 41 cooperates and abuts against the plug hole 22, the plug hole 22 is closed, making it difficult for external liquid to enter the movable valve core 3, thereby reducing the problem of impurities entering the gap between the valve core 3 and the fixed plug 2 and causing a decrease in sealing.

[0070] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions and improvements made within the spirit and principles of the present invention should be included in the protection scope of the present invention.

Claims

1. A screw drill with a multifunctional bypass valve, comprising a motor assembly, a universal shaft assembly and a transmission shaft assembly which are detachably mounted in sequence, characterized in that: Also included is a bypass valve assembly installed above the motor assembly, the bypass valve assembly having: A valve housing (1), a fixed plug (2) movably mounted in the inner cavity of the valve housing (1) from bottom to top, and a valve core (3) movably mounted in the inner cavity of the fixed plug (2) from top to bottom; a plurality of hydraulic valves (4) mounted between the inner and outer walls of the valve housing (1), and a spring assembly (5) arranged between the fixed plug (2) and the valve core (3); The valve housing (1) comprises an outer shell (11) which is connected to the upper and lower parts, and a bypass hole which penetrates both inner and outer sides of the outer shell (11), and the plurality of hydraulic valves (4) are mounted in a one-to-one correspondence at the bypass holes; The hydraulic valve (4) comprises two telescopic valve plugs (41) penetrating the housing (11), and a hydraulic flow channel (42) for pushing the two telescopic valve plugs (41) to move relative to each other by hydraulic pressure, and driving the hydraulic valve (4) to open and close when the internal and external hydraulic pressure difference of the bypass valve assembly changes; The bypass hole comprises: two bypass valve main holes (12) respectively opened on both sides of the outer shell (11) and coaxially arranged; the two telescopic valve plugs (41) are respectively inserted into the inner cavities of the two bypass valve main holes (12); a spring groove flow channel (424) and a bypass valve flow channel (428) are connected between the two bypass valve main holes (12); the spring groove flow channel (424) is connected to the inner cavity of the outer shell (11) through a hydraulic groove flow channel (426); a piston (427) is slidably connected to the inner cavity of the hydraulic groove flow channel (426); and a hydraulic medium having a pressure exceeding atmospheric pressure is filled between the hydraulic groove flow channel (426) and the spring groove flow channel (424); The two telescopic valve plugs (41) in the hydraulic valve (4) are arranged in opposite directions, and the sides of the two telescopic valve plugs (41) close to each other are connected to a side pipe (411) matching the bypass valve flow channel (428) and a main pipe (413) matching the spring groove flow channel (424), and a side pipe hole (412) penetrating inside and outside is provided at the connection between the side pipe (411) and the telescopic valve plug (41), and a clamping ring structure is formed at the opening of the main pipe (413) in a radially outwardly protruding manner, and a first compression spring (414) is wound around the outside of the main pipe (413), and two ends of the first compression spring (414) are respectively in contact with the clamping ring structure and the side wall of the hydraulic groove flow channel (426); In the bypass hole, there are provided a spring groove flow channel (424) and at least two bypass valve flow channels (428) annularly equidistantly arranged around the central axis of the spring groove flow channel (424); an annular flow channel (423) is also connected between the hydraulic groove flow channel (426) and the spring groove flow channel (424); a plurality of straight flow channels (421) and a plurality of curved flow channels (422) are connected between the annular flow channel (423) and the spring groove flow channel (424); and guide flow channels (425) are respectively connected between the annular flow channel (423) and the hydraulic groove flow channel (426); In the bypass hole, an annular flow channel (423) arranged in the shape of an annular pipe is connected to the plurality of hydraulic groove flow channels (426), and the plurality of straight flow channels (421) correspond one to one to the plurality of curved flow channels (422).

2. A screw drilling tool with a multifunctional bypass valve as claimed in claim 1, characterized in that: The valve housing (1) has an annular contraction hole (15) formed by the inner wall of the outer housing (11) contracting inwardly, an upper threaded joint (14) is provided at the top end of the outer housing (11), and the upper threaded joint (14) is configured as an internal thread structure, and a lower threaded joint (13) is provided at the bottom end of the outer housing (11), and the lower threaded joint (13) is configured as an external thread structure.

3. A screw drilling tool with a multifunctional bypass valve as claimed in claim 2, characterized in that: The fixed plug (2) comprises a plug body (21) movably arranged in the inner cavity of the outer shell (11), the top end of the plug body (21) abuts against the annular shrinkage hole (15), the plug body (21) is formed into a cylindrical structure slidably fitting the inner wall of the outer shell (11), and the bottom end of the cylindrical structure shrinks inwardly to form an annular portion, and the cylindrical structure is also provided with a plug hole (22) communicating with the inside and the outside above the annular portion.

4. A screw drilling tool with a multifunctional bypass valve as claimed in claim 3, characterized in that: The valve core (3) comprises a valve core seat (31) movably arranged in the inner cavity of the plug body (21); the top end of the valve core seat (31) abuts against the annular contraction hole (15); the outer wall of the valve core seat (31) slides in contact with the inner wall of the plug body (21); the bottom end of the valve core seat (31) is connected to a valve core rod (32) inserted and slidably connected to the annular portion; the valve core rod (32) is provided with a valve core hole (33) communicating with the inside and outside.

5. A screw drilling tool with a multifunctional bypass valve as claimed in claim 4, characterized in that: The spring assembly (5) comprises a second compression spring (51) arranged in the gap between the valve body core seat (31) and the plug body (21); one end of the second compression spring (51) abuts against the valve body core seat (31) and the other end abuts against the top end of the annular portion.

6. A screw drilling tool with a multifunctional bypass valve as claimed in claim 3, characterized in that: The plug holes (22) are arranged to correspond one to one with the hydraulic valves (4), and a protruding plug (415) is arranged on the outer side of one of the two telescopic valve plugs (41) in the hydraulic valve (4) and is adapted to abut and seal against the plug hole (22).

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