A one-way bypass valve for a screw drill and a screw drill

Abstract

This utility model relates to the field of drilling technology for soil or rock layers, specifically to a one-way bypass valve for a screw drill and the screw drill itself. The drill includes a one-way bypass valve for unidirectional drilling fluid flow. The one-way bypass valve includes a valve body with a valve sleeve inside its inner bore. A one-way valve is located at the outlet end of the valve sleeve. The one-way valve includes a one-way valve seat with a support plate at the end furthest from the valve sleeve. The support plate has a drain hole for drilling fluid passage. A compression spring is also provided on the support plate, and a valve block is located at the other end of the spring. The one-way valve seat has a shoulder near the valve sleeve to stop the valve block. The spring force causes the valve block to abut or disengage from the shoulder, thus closing or opening the one-way valve seat. The compression spring in this utility model is positioned below the valve block, preventing the valve block and spring from being washed away by the drilling fluid with significant impact force, thereby improving the reliability of the entire device.

Description

Technical Field

[0001] This utility model relates to the field of drilling technology for soil or rock, specifically to a one-way bypass valve for a screw drill and a screw drill. Background Technology

[0002] A screw drill is a type of positive displacement downhole power drill that uses drilling fluid as its power source, converting fluid pressure energy into mechanical energy. Due to its high drilling efficiency, ease of operation, and strong adaptability, it is widely used in drilling production. A screw drill mainly consists of four parts connected in sequence: a bypass valve assembly, a motor assembly, a universal joint assembly, and a drive shaft assembly. Drilling mud, a type of drilling fluid, is pumped out by the mud pump, flows through the bypass valve, and enters the motor. A certain pressure difference is created between the motor's inlet and outlet, thereby driving the rotor in the motor assembly to rotate around the stator axis. The rotational speed and torque are then transmitted to the drill bit through the universal joint and drive shaft, thus realizing the drilling operation.

[0003] The bypass valve assembly typically connects to the drill pipe at the top and the motor assembly at the bottom, its main function being to connect the annular space inside the drill string and the wellbore. During tripping and running-in operations, if the pressure difference in the drill string does not reach the standard set value, the flow orifice on the bypass valve body remains open, and the bypass valve is in a bypass state, allowing the drilling mud in the drill pipe to bypass the motor and enter the annulus. When the mud flow rate and pressure reach the standard set value, the valve core in the bypass valve moves downward and contacts the valve sleeve, closing the flow orifice on the valve body. At this point, the mud flows through the motor, converting pressure energy into mechanical energy.

[0004] Chinese utility model patent with authorization announcement number CN203547609U and authorization announcement date of 2014 / 04 / 16 discloses a one-way flow type screw drill bypass valve. The screw drill bypass valve includes a valve body with a flow hole in the circumferential direction. A valve sleeve is provided in the inner hole of the valve body. A valve core is movably installed at the inlet end of the valve sleeve for drilling fluid to enter. The valve core moves reciprocally along the inner wall of the valve sleeve by a spring to open and close the flow hole. A cross pin is fixedly connected to the inner wall of the valve sleeve. A one-way valve ball is provided at the outlet end of the valve sleeve to ensure that the drilling fluid can only flow from top to bottom. The one-way valve ball and the cross pin are connected by a spring. When the drilling fluid flows from top to bottom, and the mud in the bypass valve is greater than the drilling fluid pressure at the lower end, the one-way valve ball moves downward against the spring force, and the one-way valve opens so that the screw drill can work normally. When the mud in the bypass valve is less than the drilling fluid pressure at the lower end, the one-way valve ball blocks the lower end of the valve sleeve under the action of the spring force and the pressure difference, which can prevent the drilling fluid from flowing back and causing a blowout or pump failure.

[0005] The bypass valve is equipped with a one-way valve ball that allows drilling fluid to flow in one direction through the cooperation of a spring and the one-way valve ball. The spring that drives the one-way valve ball to move is located above the one-way valve ball. During the downward pumping of drilling fluid, due to the high flow rate and hydraulic pressure of the drilling fluid, there is a risk that the one-way valve ball and the spring, or the spring and the cross pin, may be washed away by the impact force of the drilling fluid, thus causing the one-way valve to fail. Utility Model Content

[0006] The purpose of this utility model is to provide a one-way bypass valve for screw drills and a screw drill, so as to solve the problem that the one-way valve in the prior art will fall off due to the impact force of drilling fluid, causing the one-way valve to fail.

[0007] To solve the above problems, the present invention provides a one-way bypass valve for screw drills, which adopts the following technical solution:

[0008] A one-way bypass valve for screw drilling tools includes a valve body, a valve sleeve in the inner hole of the valve body, a one-way valve at the outlet end of the valve sleeve, a one-way valve seat, a support plate at the end of the one-way valve seat away from the valve sleeve, a drain hole for drilling fluid to pass through on the support plate, a compression spring on the support plate, and a valve block at the other end of the compression spring. The one-way valve seat has a shoulder at the end near the valve sleeve for blocking the valve block, and the spring force causes the valve block to abut or disconnect from the shoulder to complete the closure or opening of the one-way valve seat.

[0009] Furthermore, the valve block has an umbrella-shaped cone cap at one end near the shoulder, and the shoulder has a conical surface that matches the taper of the cone cap.

[0010] Furthermore, the valve block has a guide rod at the end away from the shoulder, the support plate has a guide hole corresponding to the position of the guide rod, and the end of the guide rod away from the valve block can move up and down in the guide hole.

[0011] Furthermore, the guide rod passes through the compression spring and is located at the centerline of the compression spring.

[0012] Furthermore, the compression spring is located on the support plate at the center line position relative to the inner hole of the valve body.

[0013] Furthermore, the valve body is provided with a bypass flow hole on its side wall, and a filter plate is provided in the flow hole. The filter plate is provided with multiple filter holes for filtering, and the filter plate is detachably connected to the flow hole.

[0014] Furthermore, multiple flow holes are arranged circumferentially on the valve body.

[0015] Furthermore, an anti-drop component is provided in the inner hole of the valve body below the one-way valve. The anti-drop component includes an anti-drop nut that is threaded into the inner hole of the valve body. An anti-drop shaft is provided inside the anti-drop nut. One end of the anti-drop shaft that extends into the inner hole of the valve body is provided with an anti-drop boss that is stopped and engaged with the anti-drop nut. The other end extends out of the valve body and is provided with a suspension external thread for connecting with the motor rotor.

[0016] Furthermore, the diameter of the inner hole of the anti-fall component is larger than the outer diameter of the anti-fall boss.

[0017] Beneficial Effects: This invention relates to an improved one-way bypass valve for screw drilling tools. The one-way bypass valve includes a valve body. A one-way valve within the inner bore of the valve body allows drilling fluid to flow in only one direction, thus helping to prevent backflow. The impact force of the flowing drilling fluid causes the valve block to move downwards and compress the spring, opening the one-way valve. The spring's rebound property causes the valve block to abut against a shoulder, closing the one-way valve. Because the spring is located below the valve block, and the contact area between the valve block and the drilling fluid is large, the impact force on the valve block during normal drilling fluid flow is more uniform. Simultaneously, the spring's elasticity can offset some of the pressure transmitted to it, helping to avoid the risk of the valve block and spring being washed away by the drilling fluid with significant impact force, thereby improving the reliability of this location and the entire device.

[0018] To solve the above problems, the present invention provides a screw drill bit with the following technical solution:

[0019] A screw drill bit includes a one-way bypass valve for unidirectional flow of drilling fluid. The one-way bypass valve includes a valve body, a valve sleeve in the inner hole of the valve body, and a one-way valve at the outlet end of the valve sleeve. The one-way valve includes a one-way valve seat, a support plate at the end of the one-way valve seat away from the valve sleeve, a drain hole for drilling fluid to pass through on the support plate, a compression spring on the support plate, and a valve block at the other end of the compression spring. The one-way valve seat has a shoulder at the end near the valve sleeve for blocking the valve block, and the spring force causes the valve block to abut or disconnect from the shoulder to complete the closure or opening of the one-way valve seat.

[0020] Furthermore, the valve block has an umbrella-shaped cone cap at one end near the shoulder, and the shoulder has a conical surface that matches the taper of the cone cap.

[0021] Furthermore, the valve block has a guide rod at the end away from the shoulder, the support plate has a guide hole corresponding to the position of the guide rod, and the end of the guide rod away from the valve block can move up and down in the guide hole.

[0022] Furthermore, the guide rod passes through the compression spring and is located at the centerline of the compression spring.

[0023] Furthermore, the compression spring is located on the support plate at the center line position relative to the inner hole of the valve body.

[0024] Furthermore, the valve body is provided with a bypass flow hole on its side wall, and a filter plate is provided in the flow hole. The filter plate is provided with multiple filter holes for filtering, and the filter plate is detachably connected to the flow hole.

[0025] Furthermore, multiple flow holes are arranged circumferentially on the valve body.

[0026] Furthermore, an anti-drop component is provided in the inner hole of the valve body below the one-way valve. The anti-drop component includes an anti-drop nut that is threaded into the inner hole of the valve body. An anti-drop shaft is provided inside the anti-drop nut. One end of the anti-drop shaft that extends into the inner hole of the valve body is provided with an anti-drop boss that is stopped and engaged with the anti-drop nut. The other end extends out of the valve body and is provided with a suspension external thread for connecting with the motor rotor.

[0027] Furthermore, the diameter of the inner hole of the anti-fall component is larger than the outer diameter of the anti-fall boss.

[0028] Beneficial Effects: This utility model of a screw drill bit is an improved invention. The screw drill bit of this utility model includes a one-way bypass valve for unidirectional drilling fluid flow. The one-way bypass valve includes a valve body, and a one-way valve set in the inner hole of the valve body allows drilling fluid to pass through in only one direction, thus helping to prevent backflow. The impact force of the flowing drilling fluid causes the valve block to move downwards and compress the spring, thereby opening the one-way valve. The spring's rebound characteristic drives the valve block to abut against the shoulder, closing the one-way valve. Because the spring in this one-way valve is located below the valve block, and the contact area between the valve block and the drilling fluid is large, the impact force on the valve block during normal drilling fluid flow is more uniform. Simultaneously, the spring can offset some of the pressure transmitted to it through its own elasticity. This helps to avoid the risk of the valve block and spring being washed away by the drilling fluid with large impact force, thereby improving the reliability of this location and the entire device. Attached Figure Description

[0029] Figure 1 This is a schematic diagram of an embodiment of the one-way bypass valve for screw drills and a screw drill tool according to the present invention;

[0030] Figure 2 This is a schematic diagram of the one-way bypass valve in the closed state.

[0031] Figure 3 Schematic diagram of valve body structure;

[0032] Figure 4 This is a schematic diagram of a one-way valve.

[0033] In the diagram: 1. Valve body; 2. Flow hole; 3. Valve sleeve; 4. One-way valve seat; 5. Support plate; 6. Compression spring; 7. Valve block; 8. Shoulder; 9. Conical cap; 10. Conical surface; 11. Guide rod; 12. Guide hole; 13. Filter plate; 14. Anti-drop nut; 15. Anti-drop shaft; 16. Anti-drop boss; 17. Suspension external thread. Detailed Implementation

[0034] The features and performance of this utility model will be further described in detail below with reference to the embodiments.

[0035] An embodiment of the one-way bypass valve for screw drill tools of this utility model is as follows:

[0036] In this utility model, the one-way valve in the one-way bypass valve for screw drilling tools is in contact with the shoulder of the one-way valve seat through the cooperation of the valve block and the shoulder. The pressure of the drilling fluid drives the valve block to move downward to open the one-way valve. When the drilling fluid stops flowing, the pressure spring can quickly reset to drive the valve block to reset and close the one-way valve.

[0037] Based on the above inventive concept, as a basic solution, such as Figure 1-4As shown, the one-way bypass valve for screw drilling tools of this utility model includes a valve body, a valve sleeve in the inner hole of the valve body, and a one-way valve at the outlet end of the valve sleeve. The one-way valve ensures one-way flow of drilling fluid, thus preventing backflow of drilling fluid to the surface or clogging of the water hole, and damage to downhole logging instruments. The one-way valve includes a one-way valve seat, which is installed in the inner hole of the valve body by having its inlet end stop against the valve sleeve and its outlet end abut against a stepped surface formed by different orifices in the inner hole of the valve body. This ensures that the one-way valve seat is confined to its position and will not move relative to the drilling fluid due to the impact force. A support plate is provided at the end of the one-way valve seat away from the valve sleeve. The support plate has a drain hole for drilling fluid to pass through and a compression spring. The support plate is mainly used for... The spring provides the installation position and ensures that the drilling fluid can pass smoothly through the support plate position during normal circulation. The other end of the spring is equipped with a valve block. The one-way valve seat has a shoulder at the end near the valve sleeve to stop the valve block. The spring force causes the valve block and the shoulder to abut or disconnect, thus completing the closure or opening of the one-way valve seat. The spring can deform under external force and quickly return to its original state after the external force is released. Therefore, the characteristics of the spring can be used to make the valve block and the shoulder abut or disconnect. During normal drilling, the drilling fluid overcomes the spring force to push open the valve block and open the one-way valve, allowing the drilling fluid to flow normally. When the drilling fluid stops circulating or overflows or blowouts occur, the valve block abuts against the shoulder of the one-way valve seat under the action of the spring, closing the one-way valve passage and effectively preventing drilling fluid backflow.

[0038] In a preferred embodiment, the valve block has an umbrella-shaped conical cap at one end near the shoulder, and the shoulder has a conical surface that matches the taper of the conical cap. The conical surface fit facilitates the flow of drilling fluid and better withstands the impact force of the drilling fluid flow to ensure the stable operation of the one-way valve. In addition, the conical surface fit increases the contact area between the valve block and the shoulder of the one-way valve seat, which helps to form a tighter fit and improves the sealing effect when the one-way valve is closed. In other embodiments, the valve block can be set as a spherical valve block, and the contact position between the shoulder and the spherical valve block is set as a spherical surface. The contact area of ​​the spherical surface fit is also larger, which can also achieve the effect of facilitating the flow of drilling fluid and tight fit with the one-way valve seat.

[0039] In a preferred embodiment, the valve block has a guide rod at the end away from the shoulder, and the support plate has a guide hole corresponding to the position of the guide rod. The end of the guide rod away from the valve block can move up and down within the guide hole. The guide hole provides space for the guide rod to move up and down. The guide rod can guide and assist the movement of the valve block during the closing or opening of the one-way valve. In addition, the guide rod passes through the compression spring and is located at the center line of the compression spring. At this time, the guide rod helps to prevent the compression spring from rotating or deviating during compression or extension. This guiding effect helps to maintain the stability of the compression spring in a predetermined direction, thereby ensuring that the compression spring can work normally and achieve the expected effect. In other embodiments, the guide rod set at the center of the compression spring can be changed to the guide rods set on both sides of the compression spring. Although this will result in higher material consumption compared to the preferred embodiment, it can also ensure the stability of the valve block during movement. Alternatively, a flexible cover can be set outside the compression spring. The flexible cover can change with the compression or extension of the compression spring, which can also achieve the guiding effect and make the compression spring move smoothly in a predetermined direction.

[0040] In a preferred embodiment, the compression spring is located on the support plate at the center line position relative to the inner hole of the valve body. Since the one-way valve seat is disposed in the inner hole of the valve body, and the compression spring is disposed at the center of the inner hole of the valve body, the compression spring is also located at the center of the one-way valve seat. This makes the valve block disposed on the compression spring and the shoulder that mates with it also located at the center position of the one-way valve seat. This helps to balance the pressure applied by the drilling fluid to the valve block when the drilling fluid is flowing normally, so as to extend the service life of the valve block and the compression spring. In addition, the design of being located at the center position also helps to reduce the machining difficulty of the inner hole of the one-way valve seat.

[0041] As a preferred implementation method, such as Figure 1-2As shown, the valve body also has a bypass flow hole on its side wall. A filter plate is installed in the flow hole, and the filter plate has multiple filter holes for filtration. The filter plate is detachably connected to the flow hole. Drilling fluid may carry other impurities or larger rock cuttings, silt, and other particles. During its flow, these particles may cause problems such as drill string jamming or blockage, and even lead to safety accidents. The filter holes can filter these impurities to improve the purity of the drilling fluid, thereby preventing wear on internal drill string components, extending the service life of the drill string, and ensuring stable operation. The filter plate also reduces the frequency of drill string replacement. The number of cleaning cycles is reduced, thus saving time and costs and improving drilling efficiency. Furthermore, the filter element and the flow holes can be detachably connected via threaded connections, facilitating disassembly, cleaning, or replacement of the filter element. Multiple flow holes are arranged circumferentially on the valve body, which improves the flow efficiency of the drilling fluid, saving time and costs. In other embodiments, a filter membrane can be used. While the filtration speed is slower and the cost is higher, the smaller pore size of the filter membrane allows for the filtration of various smaller impurities, offering a significant advantage when drilling fluid quality requirements are extremely high. Alternatively, a metal filter screen can be used, which is lower in cost and can also achieve the filtration effect.

[0042] As a preferred implementation method, such as Figure 1-2 As shown, an anti-drop component is also provided below the one-way valve in the inner hole of the valve body. The anti-drop component includes an anti-drop nut that is threaded into the inner hole of the valve body. An anti-drop shaft is provided inside the anti-drop nut. One end of the anti-drop shaft, which extends into the inner hole of the valve body, has an anti-drop boss that engages with the anti-drop nut. The other end extends out of the valve body and has a suspension external thread for connecting to the motor rotor. During the operation of the screw drill, phenomena such as wellbore deviation or drill bit jamming may be encountered, which may cause damage to the motor rotor or other components such as the universal joint. If a component breaks or other abnormalities occur, causing the drill string to malfunction or even risk falling out, the anti-falling boss and anti-falling nut can effectively prevent these components from falling into the well and causing downhole safety accidents. This further reduces the time and cost of downtime for retrieving fallen components. In other embodiments, a removable protective sleeve is provided to wrap and protect parts that are prone to failure. This method requires frequent installation and removal of the protective sleeve, which is not very convenient, but it can still play a role in preventing falling out to a certain extent.

[0043] As a preferred implementation method, such as Figure 1-3As shown, the diameter of the inner hole of the anti-drop component is larger than the outer diameter of the anti-drop boss. This is because the end of the anti-drop shaft that extends out of the bypass valve body is connected to the motor rotor. When the motor rotor is working, it performs planetary motion, so the anti-drop shaft also performs planetary motion. Therefore, setting the diameter of the inner hole to be larger can prevent the anti-drop shaft from colliding and rubbing against the inner hole of the valve body when it is performing planetary motion. When the anti-drop shaft collides and rubs against the inner hole, it will not only affect the movement of the rotor, but also aggravate the wear of the device and reduce its service life.

[0044] The working process of the one-way bypass valve for the screw drill bit of this utility model is as follows: Figure 1-4 As shown, when drilling fluid is pumped into the screw drill bit, the bypass passage on the valve body is closed. At this time, the drilling fluid flows to the check valve. Under the impact force of the drilling fluid, the valve block in the check valve is driven to compress the spring, and the check valve opens, allowing the drilling fluid to continue to flow downward until it flows into the motor rotor, thereby driving the rotor to rotate. When the drilling fluid circulation stops or during tripping or running-in, the passage opens, and the internal space of the valve body is connected to the annulus. The drilling fluid flows into the annulus through the passage. At this time, the pressure of the drilling fluid on the valve block cannot overcome the force of the spring on the valve block, and the check valve closes, which can prevent the backflow of drilling fluid in the drill bit.

[0045] The embodiment of the screw drill of this utility model is as follows:

[0046] A screw drill bit includes a one-way bypass valve for unidirectional flow of drilling fluid, wherein an embodiment of the one-way bypass valve has been described above and will not be repeated here.

[0047] The above description is only a preferred embodiment of the present utility model and is not intended to limit the present utility model. The patent protection scope of the present utility model shall be determined by the claims. Similarly, any equivalent structural changes made based on the description and drawings of the present utility model shall also be included within the protection scope of the present utility model.

Claims

1. A one-way bypass valve for a screw drill bit, comprising a valve body, a valve sleeve disposed in the inner bore of the valve body, and a one-way valve disposed at the outlet end of the valve sleeve, characterized in that, The one-way valve includes a one-way valve seat. The one-way valve seat has a support plate at one end away from the valve sleeve. The support plate has a drain hole for drilling fluid to pass through. The support plate also has a compression spring, and the other end of the compression spring has a valve block. The one-way valve seat has a shoulder at one end near the valve sleeve for blocking the valve block. The spring force causes the valve block to abut or disconnect from the shoulder to complete the closure or opening of the one-way valve seat.

2. The one-way bypass valve for screw drills according to claim 1, characterized in that, The valve block has an umbrella-shaped cone cap at one end near the shoulder, and the shoulder has a conical surface that matches the taper of the cone cap.

3. The one-way bypass valve for screw drills according to claim 1, characterized in that, The valve block has a guide rod at the end away from the shoulder, and the support plate has a guide hole corresponding to the position of the guide rod. The end of the guide rod away from the valve block can move up and down in the guide hole.

4. The one-way bypass valve for screw drills according to claim 3, characterized in that, The guide rod passes through the compression spring and is located at the center line of the compression spring.

5. The one-way bypass valve for screw drills according to any one of claims 1-4, characterized in that, The compression spring is located on the support plate at the center line position relative to the inner hole of the valve body.

6. The one-way bypass valve for screw drills according to claim 1, characterized in that, The valve body is also provided with a bypass flow hole on its side wall. A filter plate is provided in the flow hole. The filter plate has multiple filter holes for filtering. The filter plate and the flow hole are detachably connected.

7. The one-way bypass valve for screw drills according to claim 6, characterized in that, Multiple flow holes are arranged around the valve body.

8. The one-way bypass valve for screw drills according to claim 1, characterized in that, An anti-drop component is provided in the inner hole of the valve body below the one-way valve. The anti-drop component includes an anti-drop nut that is threaded into the inner hole of the valve body. An anti-drop shaft is provided inside the anti-drop nut. One end of the anti-drop shaft that extends into the inner hole of the valve body is provided with an anti-drop boss that is stopped and engaged with the anti-drop nut. The other end extends out of the valve body and is provided with a suspension external thread for connecting to the motor rotor.

9. The one-way bypass valve for screw drills according to claim 8, characterized in that, The diameter of the inner hole of the anti-fall component is larger than the outer diameter of the anti-fall boss.

10. A screw drill bit, comprising a one-way bypass valve for unidirectional flow of drilling fluid, characterized in that, The one-way bypass valve is the one-way bypass valve as described in any one of claims 1-9.

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