A diverter valve and downhole power tool

Abstract

The application provides a flow distribution valve and a downhole power tool, the flow distribution valve comprising an upper joint, a piston, a spring and a lower joint, wherein the upper joint has an axially arranged first flow channel, the upper end of the upper joint is connected with an upstream drill string, and the lower end is fixedly and sealingly connected with the lower joint; the lower joint has an axially arranged second flow channel, the lower end of the lower joint is fixedly connected with a downstream device; the second flow channel comprises a first section and a second section; the piston and the spring are arranged in the first section, the lower end of the piston is in contact with the upper end of the spring, a central throttling hole is arranged on the piston, the central throttling hole can generate a throttling pressure difference to drive the piston to move downward to compress the spring; a flow distribution hole is arranged on the lower joint; the initial position of the piston closes the flow distribution hole; from top to bottom, the ratio of the flow distribution hole flow area to the piston downward distance increases. The downhole power tool comprises the flow distribution valve. The application has the advantages of meeting the small rated displacement requirement of a screw rod, increasing the circulating displacement, circulating the drill cuttings and the proppant out of the wellbore and the like.

Description

Technical Field

[0001] This invention relates to the field of drilling equipment technology, and more specifically, to a flow divider valve and a downhole power tool. Background Technology

[0002] Currently, shale gas development primarily employs horizontal well development. After drilling, fracturing is required, and subsequently, coiled tubing is used to drill and grind bridge plugs inside the well. During the fracturing process in shale gas horizontal wells, casing deformation frequently occurs. Therefore, the bridge plugs used are mostly soluble. However, due to various reasons, soluble bridge plugs often cannot completely dissolve inside the well, causing wellbore blockage. To remove the blockage, coiled tubing must be used to drill and grind the tubing through the well.

[0003] After casing deformation, the casing diameter decreases significantly. A screw motor and grinding shoe matched to the casing's inner diameter cannot pass through the deformation point, requiring a smaller screw motor and grinding shoe for wellbore cleaning. However, the smaller screw motor has a low rated displacement, which cannot effectively circulate drill cuttings and proppant out of the wellbore. Therefore, a diversion valve needs to be designed that meets the requirements of the small rated displacement of the screw motor while increasing the wellbore circulation capacity to effectively circulate drill cuttings and proppant out of the wellbore. Summary of the Invention

[0004] The purpose of this invention is to overcome at least one of the aforementioned deficiencies in the prior art. For example, one objective of this invention is to provide a diversion valve that increases the circulation capacity while meeting the requirements of a small rated screw displacement, enabling the circulation of drill cuttings and proppant out of the wellbore. Another objective of this invention is to provide a downhole power tool that increases the circulation capacity while meeting the requirements of a small rated screw displacement, enabling the circulation of drill cuttings and proppant out of the wellbore.

[0005] To achieve the above objectives, the present invention provides a flow divider valve, which includes an upper connector, a piston, a spring, and a lower connector, wherein...

[0006] The upper connector has an axially arranged first flow channel, the upper end of the upper connector is connected to the upstream drill string, and the lower end is fixedly and sealed to the lower connector.

[0007] The lower connector has an axially arranged second flow channel, and the lower end of the lower connector is fixedly connected to the downstream equipment; the second flow channel includes a first section and a second section, and the diameter of the first section is larger than the diameter of the second section;

[0008] The piston and spring are arranged in the first section, with the lower end of the piston in contact with the upper end of the spring, the outer wall of the piston in contact with the inner wall of the first section, and a central throttling orifice provided on the piston. The central throttling orifice can generate a throttling pressure difference when the fluid flows through, driving the piston to move downward and compress the spring.

[0009] A diversion hole is provided on the outer wall of the lower connector, and the diversion hole connects the first section with the outside of the lower connector.

[0010] The initial position of the piston closes the flow divider orifice;

[0011] From top to bottom, the ratio of the flow area of ​​the diversion orifice to the downward distance of the piston gradually increases.

[0012] In one exemplary embodiment of one aspect of the present invention, the diversion orifice may include one or more inverted T-shaped throttling orifices, which are uniformly distributed along the circumference of the lower connector and located on the same plane.

[0013] In one exemplary embodiment of one aspect of the present invention, the one or more inverted T-shaped throttling orifices may include 2 to 6.

[0014] In one exemplary embodiment of one aspect of the present invention, the diverter valve may further include a packing gland disposed on the first section and sleeved on the piston, the packing gland being disposed on the first section and capable of forming a dynamic seal with the piston surface.

[0015] In one exemplary embodiment of one aspect of the present invention, the diverter valve may further include a seal disposed between the upper connector and the lower connector.

[0016] In one exemplary embodiment of one aspect of the present invention, the upper connector may include a first cylindrical section and a second cylindrical section, wherein the outer diameter of the first cylindrical section is greater than the outer diameter of the second cylindrical section, the outer diameter of the second cylindrical section is equal to the diameter of the first section, and the second cylindrical section is disposed in the first section.

[0017] In one exemplary embodiment of one aspect of the present invention, the second cylindrical section and the first section can be fixedly connected by threads.

[0018] In one exemplary embodiment of the present invention, the lower end of the lower connector may also be provided with a housing, and the outer wall of the housing is provided with threads, and the lower end of the lower connector is fixedly connected to the downstream equipment by the threads.

[0019] In one exemplary embodiment of this invention, the input flow rate of the diverter valve can be 76-550 L / min, the output flow rate can be 76-189 L / min, and the diversion flow rate of the diverter orifice can be 0-361 L / min.

[0020] In one exemplary embodiment of one aspect of the present invention, the inner wall of the first cylindrical section may be provided with threads, and the diameter of the threads gradually decreases from top to bottom.

[0021] In another aspect, the present invention provides a downhole power tool, which may include the diversion valve described in any of the above claims.

[0022] In another exemplary embodiment of the present invention, the downhole power tool may further include a screw motor and a grinding shoe, wherein the screw motor is disposed at the lower end of the diverter valve and the grinding shoe is disposed at the lower end of the screw motor.

[0023] Compared with the prior art, the beneficial effects of the present invention include at least one of the following:

[0024] (1) The diversion valve of the present invention solves the problem that when a small rated displacement screw motor works in the casing, the working displacement of the screw motor is small, resulting in the return drilling fluid displacement being insufficient to carry drill cuttings, proppant, or other solid particles in the wellbore; by setting a diversion hole, the flow area of ​​the diversion hole increases with the increase of the drilling fluid displacement, so that the drilling fluid flow rate entering the screw motor is kept within a certain range, and the drilling fluid flow rate through the diversion hole increases with the increase of the drilling fluid displacement, thereby improving the fluid's ability to carry solid particles in the wellbore;

[0025] (2) The flow divider of the present invention adopts an inverted T-shaped flow divider, which solves the flow divider requirements of the screw motor under both load and unload conditions. When the screw motor is under load, the pressure drop through the screw motor is large, and the throttling pressure difference through the flow divider is also large under the same displacement. When the motor is unloaded, the pressure drop through the motor is small, and the throttling pressure difference through the flow divider is also small, so the flow rate through the motor will increase relatively. When the flow divider is fully open after increasing by a certain value, the flow area of ​​the flow divider will increase significantly, thereby significantly increasing the fluid flow rate through the flow divider. This ensures that the screw motor always works within the rated working displacement while also ensuring that it can circulate at a larger displacement. Attached Figure Description

[0026] The above and other objects and / or features of the present invention will become clearer from the following description taken in conjunction with the accompanying drawings, in which:

[0027] Figure 1 A schematic diagram of the structure of a flow divider valve according to an exemplary embodiment of the present invention is shown;

[0028] Figure 2 It shows Figure 1 Schematic diagram of the cross-section at point AA;

[0029] Figure 3 It shows Figure 1 A schematic diagram of the cross-section at point BB.

[0030] Explanation of reference numerals in the attached figures:

[0031] 1-Upper connector, 2-Piston, 3-Central throttle orifice, 4-Packing, 5-Spring, 6-Housing, 7-Lower connector, 8-Diverter orifice. Detailed Implementation

[0032] In the following description, a diversion valve and a downhole power tool of the present invention will be explained in detail with reference to exemplary embodiments.

[0033] Figure 1 A schematic diagram of the structure of a flow divider valve according to an exemplary embodiment of the present invention is shown; Figure 2 It shows Figure 1 Schematic diagram of the cross-section at point AA; Figure 3 It shows Figure 1 A schematic diagram of the cross-section at point BB.

[0034] In a first exemplary embodiment of the present invention, as Figure 1 As shown, the diversion valve mainly includes an upper connector 1, a piston 2, a spring 5, and a lower connector 7.

[0035] The upper connector 1 has an axially arranged first flow channel. The upper end of the upper connector 1 is fixedly connected to the upstream drill string to transmit the torque of the upstream drill string and receive drilling fluid in the upstream drill string. The lower end of the upper connector 1 is fixedly and sealed to the upper end of the lower connector 7, thereby driving the lower connector and the upper connector to rotate or move together.

[0036] The lower connector 7 has an axially arranged second flow channel that communicates with the first flow channel to receive drilling fluid from the first flow channel. The lower end of the lower connector 7 is fixedly connected to downstream equipment to transmit torque or supply drilling fluid. Here, the drilling fluid can be drilling liquid. The second flow channel includes a first section and a second section connected end-to-end, with the first section situated above the second section and having a diameter larger than that of the second section, thus forming a step at the junction of the first and second sections.

[0037] Piston 2 and spring 5 are disposed in the first section, with the lower end of piston 2 contacting the upper end of spring 5. The outer wall of piston 2 contacts the inner wall of the first section. A central throttling orifice 3 is provided on the piston, which generates a throttling pressure differential when drilling fluid flows through, causing piston 2 to move downward and compress spring 5. Here, the upper end face of piston 2 can contact the lower end face of the upper connector, thereby limiting the upward movement of piston 2 in the first section. However, the invention is not limited to this; a limiting member can also be provided in the second section to limit the upward movement of piston. The lower end of spring 5 contacts the step at the connection between the first and second sections.

[0038] A flow divider hole 8 is provided on the outer wall of the lower connector 7, which connects the first section to the outside of the lower connector. The piston 2, in its initial position in the first section, closes the flow channel of the flow divider hole 8.

[0039] From top to bottom, the ratio of the flow area of ​​the diversion orifice to the downward distance of the piston gradually increases. Specifically, as the piston travels a greater distance downward in the first stage, the flow area of ​​the diversion orifice increases significantly, thereby significantly increasing the diversion flow rate of the diversion orifice.

[0040] In this exemplary embodiment, as Figures 1-3 As shown, the diversion orifice 8 may include one or more inverted T-shaped throttling orifices, which are evenly distributed along the circumference of the lower connector and located on the same plane.

[0041] Furthermore, the more than one inverted T-shaped throttling orifice may include 2 to 6. For example, such as Figure 1 As shown, the more than one inverted T-shaped throttling orifice includes three orifices, which are circumferentially distributed on the lower connector sidewall at 120° intervals from each other.

[0042] In this exemplary embodiment, as Figure 1 As shown, the diverter valve may further include packing 4, which can be disposed on the first section and can form a dynamic seal with the piston surface. Here, a groove is provided circumferentially on the inner wall of the first section, and the packing is disposed in the groove. The inner surface of the packing contacts the outer circumferential surface of the piston, thereby dividing the first section into upper and lower cavities.

[0043] In this exemplary embodiment, as Figure 1 As shown, the diversion valve may also include a seal. Figure 1 (Not shown in the text), the sealing element is disposed between the upper connector and the lower connector to achieve a seal between the upper connector and the lower connector.

[0044] In this exemplary embodiment, as Figure 1 As shown, the upper connector may include a first cylindrical section and a second cylindrical section, the first cylindrical section and the second cylindrical section are connected end to end, and the outer diameter of the first cylindrical section is larger than the outer diameter of the second cylindrical section, the outer diameter of the second cylindrical section is equal to the diameter of the first section, and the second cylindrical section is disposed in the first section.

[0045] In this exemplary embodiment, as Figure 1 As shown, the second cylindrical section and the first section can be fixedly connected by threads. However, the present invention is not limited to this, and other connection methods are also possible.

[0046] In the exemplary embodiments of this invention, such as Figure 1 As shown, the lower end of the lower connector may also be provided with a housing 6, and the outer wall of the housing 6 is provided with threads, and the lower end of the lower connector is fixedly connected to the downstream equipment by the threads.

[0047] In this exemplary embodiment, the input flow rate of the diversion valve can be 76–550 L / min, the output flow rate can be 76–189 L / min, and the diversion flow rate of the diversion orifice can be 0–361 L / min. In this exemplary embodiment, the inner wall of the first cylindrical section may be provided with threads, and the diameter of the threads gradually decreases from top to bottom.

[0048] In a second exemplary embodiment of the present invention, the downhole power tool may include the diversion valve described in the first exemplary embodiment above.

[0049] In this exemplary embodiment, the downhole power tool may further include a screw motor and a grinding shoe. The screw motor is disposed below the flow divider valve, and the grinding shoe is disposed below the screw motor. Here, the screw motor is a screw motor with a small rated displacement (e.g., a rated displacement of 76–189 L / min). After casing deformation, the casing diameter is significantly reduced, and the screw motor and grinding shoe matched to the casing inner diameter cannot pass through the casing deformation point. A smaller screw motor and grinding shoe are required to drill and purify the well.

[0050] In summary, the beneficial effects of the present invention include at least one of the following:

[0051] (1) The diversion valve of the present invention solves the problem that when a small rated displacement screw motor works in the casing, the working displacement of the screw motor is small, resulting in the return drilling fluid displacement being insufficient to carry drill cuttings, proppant, or other solid particles in the wellbore; by setting a diversion hole, the flow area of ​​the diversion hole increases with the increase of the drilling fluid displacement, so that the drilling fluid flow rate entering the screw motor is kept within a certain range, and the drilling fluid flow rate through the diversion hole increases with the increase of the drilling fluid displacement, thereby improving the fluid's ability to carry solid particles in the wellbore;

[0052] (2) The flow divider of the present invention adopts an inverted T-shaped flow divider, which solves the flow divider requirements of the screw motor under both load and unload conditions. When the screw motor is under load, the pressure drop through the screw motor is large, and the throttling pressure difference through the flow divider is also large under the same displacement. When the motor is unloaded, the pressure drop through the motor is small, and the throttling pressure difference through the flow divider is also small, so the flow rate through the motor will increase relatively. When the flow divider is fully open after increasing by a certain value, the flow area of ​​the flow divider will increase significantly, thereby significantly increasing the fluid flow rate through the flow divider. This ensures that the screw motor always works within the rated working displacement while also ensuring that it can circulate at a larger displacement.

[0053] Although the present invention has been described above in conjunction with exemplary embodiments and accompanying drawings, those skilled in the art should understand that various modifications can be made to the above embodiments without departing from the spirit and scope of the claims.

Claims

1. A flow divider valve, characterized in that, The diverter valve includes an upper connector, a piston, a spring, and a lower connector, wherein, The upper connector has an axially arranged first flow channel, the upper end of the upper connector is connected to the upstream drill string, and the lower end is fixedly and sealed to the lower connector. The lower connector has an axially arranged second flow channel, and the lower end of the lower connector is fixedly connected to the downstream equipment; the second flow channel includes a first section and a second section, and the diameter of the first section is larger than the diameter of the second section; The piston and spring are arranged in the first section, with the lower end of the piston in contact with the upper end of the spring, the outer wall of the piston in contact with the inner wall of the first section, and a central throttling orifice provided on the piston. The central throttling orifice can generate a throttling pressure difference when the fluid flows through, driving the piston to move downward and compress the spring. A diversion hole is provided on the outer wall of the lower connector, which connects the first section with the outside of the lower connector; the diversion hole includes one or more inverted T-shaped throttling holes, which are evenly distributed along the circumference of the lower connector and located on the same plane; The initial position of the piston closes the flow divider orifice; From top to bottom, the ratio of the flow area of ​​the diversion orifice to the downward distance of the piston gradually increases.

2. The flow divider valve according to claim 1, characterized in that, The number of inverted T-shaped throttling orifices mentioned above includes 2 to 6.

3. The flow divider valve according to claim 1, characterized in that, The diverter valve also includes a packing gland, which is disposed on the first section and can form a dynamic seal with the piston surface.

4. The flow divider valve according to claim 1, characterized in that, The diverter valve also includes a seal, which is disposed between the upper connector and the lower connector.

5. The flow divider valve according to claim 1, characterized in that, The upper connector includes a first cylindrical section and a second cylindrical section, wherein the outer diameter of the first cylindrical section is larger than the outer diameter of the second cylindrical section, and the outer diameter of the second cylindrical section is equal to the diameter of the first section, and the second cylindrical section is disposed in the first section.

6. The flow divider valve according to claim 5, characterized in that, The second cylindrical section is fixedly connected to the first section by threads.

7. The flow divider valve according to claim 1, characterized in that, The lower end of the lower connector is also provided with a housing, and the outer wall of the housing is provided with threads, and the lower end of the lower connector is fixedly connected to the downstream equipment by the threads.

8. The flow divider valve according to claim 1, characterized in that, The input flow rate of the diverter valve is 76~550L / min, the output flow rate is 76~189L / min, and the diversion flow rate of the diverter orifice is 0~361L / min.

9. The flow divider valve according to claim 5, characterized in that, The inner wall of the first cylindrical section is provided with threads, and the diameter of the threads gradually decreases from top to bottom.

10. A downhole power tool, characterized in that, The downhole power tool includes a diversion valve as described in any one of claims 1 to 9; the downhole power tool also includes a screw motor and a grinding shoe, wherein the screw motor is disposed at the lower end of the diversion valve and the grinding shoe is disposed at the lower end of the screw motor.

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