Continuous circulation well drilling tripping mud channel switching valve

Abstract

The utility model discloses a continuous circulation drilling tripping mud channel switching valve which comprises a pup joint body, a normally-open main through valve and a normally-closed bypass valve. The normally-open main through valve and the pup joint body are coaxially arranged and installed, and the normally-closed bypass valve is arranged on the side wall, located on the lower portion of the normally-open main through valve, of the pup joint body. The normally-open main through valve comprises a main valve body, a main valve element and a movable sliding block. The normally-closed bypass valve comprises a bypass valve seat, a bypass valve element, a plug, a plug core and a double-clack check valve. The overall structure is simple and ingenious, the service life is long, when circulating drilling fluid is switched between the main circulating channel and the bypass circulating channel, the normally-open main through valve can be automatically opened or closed through hydraulic pressure difference, the equivalent circulating density of a well annulus is effectively controlled, underground pressure fluctuation caused by pump starting and stopping is avoided, and the working efficiency is improved. Meanwhile, the normally-closed bypass valve achieves elastic reset of the two valve clacks through the torsional spring serving as an elastic piece, the reset structure is simplified, the sealing piece is arranged in the direction opposite to the fluid flowing direction, and the service life of the normally-closed bypass valve is prolonged.

Description

Technical field:

[0001] The invention belongs to a petroleum drilling tool, and in particular relates to a continuous circulation drilling tripping mud channel switching valve applied in the continuous circulation drilling technology. Background technology:

[0002] During drilling operations, when connecting single rods or columns and tripping the drill bit, pump shutdowns and restarts can cause fluctuations in bottomhole pressure, leading to a series of complex downhole problems. Continuous circulation drilling technology was developed to address this issue. This technology primarily utilizes a continuous circulation valve to close the positive circulation channel when connecting or disconnecting single rods or columns, and to open the bypass circulation channel of the continuous circulation valve for continuous circulation. This maintains a constant drilling circulation rate and equivalent density, preventing accidents or complex situations such as well wall collapse, overflow, sand settling, and drill bit sticking caused by stopping circulation when connecting or disconnecting single rods or columns.

[0003] At present, common continuous circulation valves mainly include three-way ball valves, ball valve-plate valves, double-plate valves and other main forms. However, due to the influence of structural components, although the three-way ball valve and the ball valve-plate valve combination structure can achieve continuous circulation drilling, there is a problem that the ball core is difficult to rotate under the action of the fluid pressure in the drill string. Moreover, both structures require wellhead personnel to manually operate the switch of the ball valve part, resulting in a low degree of automation response and a slow response speed.

[0004] The current dual-plate valve structure uses a return spring to open and close the main valve disc. However, due to the long-term exposure of the return spring to erosion by the circulating drilling fluid, problems such as erosion of the center valve disc, which can lead to seal failure, long-term stress damage to the return spring, and the inability to run the inclination-while-drilling tool into the drill string, all affect operational safety. Furthermore, the bypass valve seal is exposed to erosion by the circulating drilling fluid, which can easily lead to seal failure and shorten the bypass valve's service life.

[0005] Chinese Patent No. 2011101301394 discloses an uninterrupted circulation short-circuit for oil drilling and a method for continuously circulating mud therein. The uninterrupted circulation short-circuit comprises a short-circuit body, an automatic center gate valve, and a lateral normally closed check valve. When it is necessary to disassemble and assemble the drill pipe, make or break the drill pipe, or trip the drill, the mud is continuously circulated through the lateral normally closed check valve. Although the pressure of the circulating mud is also used to automatically close the automatic center gate valve, the position of the gate valve cover is parallel to the axis of the circulation channel when the automatic center gate valve is in the open state, resulting in unclear sensing of pressure changes on both sides of the center gate valve and slow response speed. Problem: Since the gate valve cover is fixed to the valve cylinder by only a single pin shaft, when the pressure on both sides of the center gate valve suddenly changes, it is easy to cause shaking, affecting the working stability of the gate valve; in addition, since the diameter of the lower end channel of the center gate valve becomes smaller and there is no reducing section for buffering, turbulence is easy to generate, which increases the erosion effect on the pipe wall and aggravates the wear of the pipe wall; at the same time, its lateral normally closed single-flow valve is closed and opened by a single valve cover under the action of a torsion spring for the entire bypass valve. When under the action of high flow rate or large flow of mud, there will be a problem that the valve cover is not closed quickly enough, and due to the lack of seals between the valve cover and the valve body, leakage problems are prone to occur. Summary of the invention:

[0006] The purpose of the present invention is to overcome the deficiencies of the prior art and provide a continuous circulation drilling tripping mud channel switching valve that utilizes drilling fluid pressure to quickly switch between a positive circulation channel and a bypass circulation channel.

[0007] The object of the present invention is achieved through the following technical solutions:

[0008] A continuous circulation drilling tripping mud channel switching valve is characterized in that: the continuous circulation drilling tripping mud channel switching valve comprises a short-circuit body, a retaining spring, a retaining ring, a normally open main valve, a normally closed bypass valve and a pressure block, wherein the retaining ring is arranged at a positioning groove of the short-circuit body, the retaining spring is clamped in a limiting groove of the retaining ring, and the retaining ring is arranged on the inner wall of the retaining ring below the retaining spring; the normally open main valve and the short-circuit body are arranged and installed coaxially, and the normally closed bypass valve is arranged on a side wall of the short-circuit body located below the normally open main valve, and the position of the normally closed bypass valve on the side wall of the short-circuit body is limited by the pressure block;

[0009] The normally open main valve comprises a main valve core, a movable slider and a main valve body; the main valve core and the movable slider are both coaxially arranged and installed with the main valve body;

[0010] The normally closed bypass valve includes a bypass valve seat, a bypass valve core, a plugging core, a plugging double-flap check valve and a pin shaft; the bypass valve core is installed in the bypass valve seat through a threaded connection, the plugging core is coaxially installed in the plug through a threaded connection, and the plug is installed in the bypass valve core through a threaded connection;

[0011] The double-flap check valve comprises a positioning valve seat, a torsion spring and a valve disc; the valve disc is two in number and is connected to the positioning valve seat via a torsion spring; the positioning valve seat of the double-flap check valve is hinged to the bypass valve seat via a pin shaft;

[0012] The short-circuit body is cylindrical, with an upper hole diameter larger than a lower hole diameter, and is internally provided with a main circulation pipeline, a bypass circulation pipeline, a connecting box, a connecting groove, and a connecting pin. The upper end is connected to the drill pipe via the connecting box, and the lower end is connected to the drill pipe via the connecting pin. The pressure block is used to define the position of the normally closed bypass valve on the side wall of the short-circuit body through the connecting groove.

[0013] The main valve core is provided with a limiting protrusion, a positioning groove and a sliding groove; the main valve body is installed and matched with the main valve core through the limiting protrusion; the movable slide is positioned relative to the main valve core through the positioning groove;

[0014] The movable slider is a cup-shaped body with a positioning protrusion on the upper part. By cooperating with the positioning groove on the main valve core, the position of the movable slider is limited when the normally open main valve is closed. The side walls are evenly distributed with multiple fluid channels and slides. The slides cooperate with the slide grooves on the main valve core so that the movable slider can move along the slide grooves on the main valve core. The bottom has an arc-shaped protrusion, the size of which is the same as the inner diameter of the main valve core.

[0015] The main valve body is a variable diameter body with a wide mouth on the lower side, which can slow down the flow rate of the circulating drilling fluid and disperse the impact force of the circulating drilling fluid, avoid turbulence or eddy currents, and reduce wear or erosion on the pipe wall. The main valve body is provided with a sealing groove I and a trapezoidal protrusion. A sealing ring is added to the sealing groove I to achieve sealing between the main valve body and the short-circuit body, and the trapezoidal protrusion is used to limit the position of the movable slider when the normally open main valve is opened.

[0016] The bypass valve seat is provided with a threaded hole I, a threaded hole II, a sealing groove II, a sealing groove III and a sealing groove IV; the threaded hole I on the bypass valve seat and the connecting groove are mounted on the side wall of the short-circuit body via a pressing block, the threaded hole II on the bypass valve seat is connected to the positioning valve seat on the double-flap check valve via a pin shaft, the bypass valve seat is sealed with the bypass valve core by adding a sealing ring in the sealing groove II, is sealed with the short-circuit body by adding a sealing ring in the sealing groove III, and is contact-sealed with the valve disc by adding a sealing ring in the sealing groove IV;

[0017] The plug core is provided with a sealing groove V, and a sealing ring is added in the sealing groove V to achieve sealing with the plug;

[0018] The plug is provided with a through hole, a sealing groove VI and a glue coating groove; the through hole needs to be kept open to reduce the air pressure, and a sealing ring is added to the sealing groove VI to achieve sealing with the bypass valve core, and glue is applied in the glue coating groove to achieve contact sealing with the end of the plug core;

[0019] The positioning valve seat is provided with a support shaft I and a support shaft II; the torsion spring is two in number and is installed on the support shaft II, with one end connected to the support shaft I and the other end connected to the torsion spring groove on the valve disc;

[0020] The valve disc is provided with a mounting boss and a torsion spring groove, and a rubber layer is provided on the edge; the valve disc is mounted on the support shaft II through the mounting boss.

[0021] Furthermore, in the above-mentioned continuous circulation drilling tripping mud channel switching valve, the positioning valve seat is hinged to the bypass valve seat through a pin shaft, and adopts an articulated rod installation method, which is convenient to install and easy to replace.

[0022] Furthermore, in the above-mentioned continuous circulation drilling tripping mud channel switching valve, the valve disc is tightly pressed against the bypass valve seat under the action of the torsion spring, and a contact seal is formed between the valve disc and the bypass valve seat.

[0023] Furthermore, in the above-mentioned continuous circulation drilling mud channel switching valve, the plug is installed on the plug through a threaded connection, the plug is installed on the bypass valve core through a threaded connection, the bypass valve core is installed on the bypass valve seat through a threaded connection, and the bypass valve seat is installed on the side wall of the short-circuit body through a threaded connection.

[0024] Furthermore, in the above-mentioned continuous circulation drilling tripping mud channel switching valve, the following steps are included:

[0025] S1: Connect the side circulation pipeline to the normally closed bypass valve, open the bypass circulation channel, close the positive circulation channel and reduce the pressure of the top drive circulating drilling fluid entering through the short-circuit body. Instead, the drilling fluid enters the short-circuit body through the normally closed bypass valve on the side wall of the short-circuit body for circulation.

[0026] S2: Increase the pressure of the circulating drilling fluid entering the short-circuit body through the normally closed bypass valve on the side wall of the short-circuit body, so that the arc-shaped protrusion of the movable slider in the normally open main valve blocks the inner diameter of the main valve core under the pressure of the circulating drilling fluid on both sides, and the normally open main valve installed coaxially with the short-circuit body is automatically closed;

[0027] S3: Open the positive circulation channel and close the bypass circulation channel, reducing the pressure of the drilling fluid circulating inside the short-circuit body through the normally closed bypass valve on the side wall of the short-circuit body; the valve disc automatically closes under the action of the torsion spring, realizing the closure of the normally closed bypass valve on the side wall of the short-circuit body;

[0028] S4: Increase and restore the pressure of the top drive circulating drilling fluid entering the top of the short-circuit body, so that the arc-shaped protrusion of the movable slider in the normally open main valve leaves the inner diameter of the main valve core under the pressure of the drilling circulating fluid on both sides and contacts the trapezoidal protrusion on the main valve body. The circulating drilling fluid flows out through the fluid channel on the side wall of the movable slider, realizing the automatic opening of the normally open main valve;

[0029] S5: Remove the side circulation pipeline connected to the normally closed bypass valve.

[0030] Furthermore, in the above-mentioned continuous circulation drilling mud channel switching valve, when it is necessary to disassemble and assemble the drill pipe, make and break the drill pipe, and trip the drill pipe, the drilling fluid is continuously circulated through the normally closed bypass valve, and the normally open main valve above the normally closed bypass valve is automatically closed by utilizing the pressure difference of the circulating drilling fluid.

[0031] The beneficial effects of the present invention are:

[0032] 1. The overall structure of the continuous circulation drilling tripping mud channel switching valve is simple and ingenious, and it is easy to assemble and disassemble. At the same time, the main valve avoids the use of a return spring, which effectively increases its service life.

[0033] 2. When the circulating drilling fluid switches between the main circulation channel and the bypass circulation channel, the normally open main valve can be automatically opened or closed by utilizing the hydraulic pressure difference, effectively controlling the equivalent circulation density of the wellbore annulus and avoiding downhole pressure fluctuations caused by starting and stopping the pump. The movable slider is coaxially arranged with the channel, and the pressure changes on both sides of the main circulation channel are obviously sensed and the response speed is faster. At the same time, the slide on the main valve core can limit the position of the movable slider, thereby improving the working stability and preventing the movable slider from axial rotation when subjected to high pressure.

[0034] 3. The normally closed bypass valve adopts a double-flap check valve with a torsion spring as the elastic part. The elastic reset of the two valve discs can be achieved by the elastic part alone, which simplifies the reset structure, closes more thoroughly, and prevents leakage more effectively. At the same time, the double-flap check valve adopts a hinged installation method, which is more convenient to assemble and easy to replace when elastic fatigue occurs.

[0035] 4. The bypass valve sealing components are all set to face away from the fluid flow direction, which can effectively avoid erosion of the rubber sealing part and increase the service life of the bypass valve. It can be applied to continuous circulation drilling operations under various drilling conditions, and has good continuity and is not easy to be interrupted. At the same time, a rubber layer is provided on the edge of the valve disc to better prevent leakage and improve the sealing performance of the valve. It is also more suitable for high flow rate and high pressure pipeline systems. Description of the drawings:

[0036] Figure 1 It is a structural schematic diagram of the present invention;

[0037] Figure 2It is a structural schematic diagram of the retaining spring of the present invention;

[0038] Figure 3 It is a structural schematic diagram of the card flap of the present invention;

[0039] Figure 4 Schematic diagram of the structure of the retaining ring of the present invention;

[0040] Figure 5 This is a structural diagram of the normally open main valve of the present invention when it is open;

[0041] Figure 6 This is a schematic structural diagram of the normally open main valve of the present invention when it is closed;

[0042] Figure 7 This is a one-third cross-sectional view of the normally open main valve structure of the present invention;

[0043] Figure 8 A schematic structural diagram of the main valve core of the present invention;

[0044] Figure 9 A schematic structural diagram of the movable slider of the present invention;

[0045] Figure 10 An exploded view of the structure of the normally closed bypass valve of the present invention;

[0046] Figure 11 A schematic structural diagram of the bypass valve seat of the present invention;

[0047] Figure 12 A schematic structural diagram of the bypass valve core of the present invention;

[0048] Figure 13 A schematic structural diagram of the plugging core of the present invention;

[0049] Figure 14 A schematic structural diagram of the plug of the present invention;

[0050] Figure 15 A schematic structural diagram of a double-flap check valve according to the present invention;

[0051] Figure 16 A schematic structural diagram of the positioning valve seat of the present invention;

[0052] Figure 17 A schematic structural diagram of a torsion spring according to the present invention;

[0053] Figure 18 A schematic structural diagram of the valve disc of the present invention;

[0054] In the figure, 1-short-circuit body, 101-connecting female buckle, 102-connecting groove, 103-connecting male buckle, 2-circlip, 3-card flap, 301-limiting groove, 4-retaining ring, 5-normally open main valve, 6-main valve core, 601-limiting protrusion, 602-positioning groove, 603-slide groove, 7-movable slider, 701-positioning protrusion, 702-fluid channel, 703-slideway, 704-arc-shaped protrusion, 8-main valve body, 801-sealing groove I, 802-trapezoidal protrusion, 9-normally closed bypass valve, 10-bypass valve seat, 100 1-threaded hole I, 1002-threaded hole II, 1003-sealing groove II, 1004-sealing groove III, 1005-sealing groove IV, 11-bypass valve core, 12-plugging core, 1201-sealing groove V, 13-plug, 1301-through hole, 1302-sealing groove VI, 1303-glue coating groove, 14-double-flap check valve, 15-pin shaft, 16-positioning valve seat, 1601-support shaft I, 1602-support shaft II, 17-torsion spring, 18-valve disc, 1801-mounting boss, 1802-torsion spring groove, 19-pressure block. Specific implementation method:

[0055] The technical solution of the present invention is described clearly and completely below with reference to the accompanying drawings. It is apparent that the embodiments described are only a portion of the embodiments of the present invention, not all of them. All other embodiments derived by persons of ordinary skill in the art based on the embodiments of the present invention without inventive effort are intended to fall within the scope of protection of the present invention.

[0056] In the description of the present invention, it should be noted that the directions or positional relationships indicated by terms such as "center," "up," "down," "left," "right," "vertical," "horizontal," "inside," and "outside" are based on the directions or positional relationships described in the accompanying drawings and are intended solely to facilitate and simplify the description of the present invention. They are not intended to indicate or imply that the devices or components referred to must have a specific orientation, be constructed, or operate in a specific orientation. Therefore, they should not be construed as limitations on the present invention. Furthermore, terms such as "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance.

[0057] In the description of the present invention, it should be noted that, unless otherwise expressly specified or limited, the terms "mounted," "connected," and "connected" should be understood in a broad sense. For example, they may refer to fixed connections, detachable connections, or integral connections; mechanical connections or electrical connections; direct connections or indirect connections through an intermediate medium; and internal communication between two components. Those skilled in the art will understand the specific meanings of the above terms in the present invention.

[0058] like Figures 1 to 8As shown, this embodiment is a continuous circulation drilling tripping mud channel switching valve, which includes a short-circuit body 1, a clamping spring 2, a clamping flap 3, a retaining ring 4, a normally open main valve 5, a normally closed bypass valve 9 and a pressure block 19, wherein the clamping flap 3 is arranged at the positioning clamping groove of the short-circuit body 1, the clamping spring 2 is clamped in the limiting groove 301 of the clamping flap 3, and the retaining ring 4 is arranged on the inner wall of the clamping flap 3 below the clamping spring 2; the normally open main valve 5 is coaxially arranged and installed with the short-circuit body 1, and the normally closed bypass valve 9 is arranged on the side wall of the short-circuit body 1 located below the normally open main valve 5, and the position of the normally closed bypass valve 9 on the side wall of the short-circuit body 1 is limited by the pressure block 19;

[0059] In this embodiment, the normally open main valve 5 includes a main valve core 6, a movable slider 7 and a main valve body 8; the main valve core 6 and the movable slider 7 are both coaxially arranged and installed with the main valve body 8;

[0060] In this embodiment, the normally closed bypass valve 9 includes a bypass valve seat 10, a bypass valve core 11, a plug 12, a plug 13, a double-flap check valve 14, and a pin 15; the bypass valve core 11 is installed in the bypass valve seat 10 through a threaded connection, the plug 12 is coaxially installed in the plug 13 through a threaded connection, and the plug 13 is installed in the bypass valve core 11 through a threaded connection;

[0061] In this embodiment, the double-flap check valve 14 includes a positioning valve seat 16, a torsion spring 17, and a valve disc 18. The valve disc 18 is two in number and is connected to the positioning valve seat 16 via the torsion spring 17. The positioning valve seat 16 of the double-flap check valve 14 is hinged to the bypass valve seat 10 via a pin 15.

[0062] In this embodiment, the short-circuit body 1 is cylindrical, with an upper hole diameter larger than a lower hole diameter. A main circulation pipeline, a bypass circulation pipeline, a connecting box 101, a connecting groove 102, and a connecting pin 103 are provided inside. The upper end is connected to the drill pipe via the connecting box 101, and the lower end is connected to the drill pipe via the connecting pin 103. The pressure block 19 is connected to the normally closed bypass valve 9 on the side wall of the short-circuit body 1 through the connecting groove 102.

[0063] In this embodiment, the main valve core 6 is provided with a limiting protrusion 601, a positioning groove 602 and a sliding groove 603; the main valve body 8 is installed and matched with the main valve core 6 through the limiting protrusion 601; the movable slider 7 is positioned relative to the main valve core 6 through the positioning groove 602;

[0064] In this embodiment, the movable slider 7 is a cup-shaped body with a positioning protrusion 701 on the upper portion. By cooperating with the positioning groove 602 on the main valve core 6, the position of the movable slider 7 is determined when the normally open main valve 5 is closed. The side wall is evenly distributed with multiple fluid channels 702 and slideways 703. The slideways 703 cooperate with the slide grooves 603 on the main valve core 6 so that the movable slider 7 can move on the main valve core 6 along the slide grooves 603. The bottom has an arc-shaped protrusion 704, the size of which is the same as the inner diameter of the main valve core 6.

[0065] In this embodiment, the main valve body 8 is a variable diameter body with a wide mouth on the lower side, which can slow down the flow rate of the circulating drilling fluid and disperse the impact force of the circulating drilling fluid, avoid turbulence or eddy currents, and reduce wear or erosion on the pipe wall. The main valve body 8 is provided with a sealing groove I 801 and a trapezoidal protrusion 802. A sealing ring is added to the sealing groove I 801 to achieve sealing between the main valve body 8 and the short-circuit body 1. The trapezoidal protrusion 802 is used to limit the position of the movable slider 7 when the normally open main valve 5 is opened.

[0066] In this embodiment, the bypass valve seat 10 is provided with a threaded hole I1001, a threaded hole II1002, a sealing groove II1003, a sealing groove III1004 and a sealing groove IV1005; the threaded hole I1001 on the bypass valve seat 10 and the connecting groove 102 are mounted on the side wall of the short-circuit body 1 via a pressing block 19, the threaded hole II1002 on the bypass valve seat 10 is connected to the positioning valve seat 16 on the double-flap check valve 14 via a pin 15, the bypass valve seat 10 is sealed with the bypass valve core 11 by adding a sealing ring in the sealing groove II1003, is sealed with the short-circuit body 1 by adding a sealing ring in the sealing groove III1004, and is formed into a contact seal with the valve disc by adding a sealing ring in the sealing groove IV1005;

[0067] In this embodiment, a sealing groove V1201 is provided on the plug core 12, and a sealing ring is added in the sealing groove V1201 to achieve sealing with the plug 13;

[0068] In this embodiment, the plug 13 is provided with a through hole 1301, a sealing groove VI 1302, and a glue coating groove 1303. The through hole 1301 needs to be kept open to reduce the air pressure. A sealing ring is added to the sealing groove VI 1302 to achieve sealing with the bypass valve core 11. Glue is applied to the glue coating groove 1303 to achieve contact sealing with the end of the plug core 12.

[0069] In this embodiment, the positioning valve seat 16 is provided with a support shaft I 1601 and a support shaft II 1602 ; the torsion spring 17 is two in number and is mounted on the support shaft II 1602 , with one end connected to the support shaft I 1601 and the other end connected to the torsion spring groove 1802 on the valve disc 18 ;

[0070] In this embodiment, a mounting boss 1801 and a torsion spring groove 1802 are provided on the valve flap 18 , and a rubber layer is provided on the edge; the valve flap 18 is mounted on the support shaft II 1602 via the mounting boss 1801 .

[0071] In this embodiment, the positioning valve seat 16 is hinged to the bypass valve seat 10 through the pin shaft 15, and adopts an articulated rod installation method, which is convenient to install and easy to replace.

[0072] In this embodiment, the valve flap 18 is tightly pressed against the bypass valve seat 10 under the action of the torsion spring 17 , and a contact seal is formed between the valve flap 18 and the bypass valve seat 10 .

[0073] In this embodiment, the plug core 12 is installed on the plug 13 through a threaded connection, the plug 13 is installed on the bypass valve core 11 through a threaded connection, the bypass valve core 11 is installed on the bypass valve seat 10 through a threaded connection, and the bypass valve seat 10 is installed on the side wall of the short-circuit body 1 through a threaded connection.

[0074] In this embodiment, the specific working process of the continuous circulation drilling tripping mud channel switching valve includes the following steps:

[0075] S1: Connect the side circulation pipeline to the normally closed bypass valve 9, open the bypass circulation channel, close the positive circulation channel and reduce the pressure of the top drive circulating drilling fluid entering through the short-circuit body 1. Instead, the drilling fluid enters the short-circuit body through the normally closed bypass valve 9 on the side wall of the short-circuit body 1 to be used as circulating drilling fluid;

[0076] S2: Increase the pressure of the circulating drilling fluid entering the short-circuit body 1 through the normally closed bypass valve 9 on the side wall of the short-circuit body 1, so that the arc-shaped protrusion 704 of the movable slider 7 in the normally open main valve 5 blocks the inner diameter of the main valve core 6 under the pressure of the circulating drilling fluid on both sides, thereby achieving the automatic closing of the normally open main valve 5 coaxially arranged with the short-circuit body 1;

[0077] S3: Open the positive circulation channel and close the bypass circulation channel, reducing the pressure of the drilling fluid circulating inside the short-circuit body 1 through the normally closed bypass valve 9 on the side wall of the short-circuit body 1; the valve disc 18 automatically closes under the action of the torsion spring 17, thereby closing the normally closed bypass valve 9 on the side wall of the short-circuit body 1;

[0078] S4: Increase and restore the pressure of the top drive circulating drilling fluid entering the top of the short-circuit body 1, so that the arc-shaped protrusion 704 of the movable slider 7 in the normally open main valve 5 leaves the inner diameter of the main valve core 6 under the pressure of the drilling circulating fluid on both sides and contacts the trapezoidal protrusion 802 on the main valve body 8. The circulating drilling fluid flows out through the fluid channel 702 on the side wall of the movable slider 7, and the normally open main valve 5 is automatically opened.

[0079] S5: Remove the side circulation pipeline connected to the normally closed bypass valve 9.

[0080] In this embodiment, when it is necessary to disassemble and assemble the drill pipe, make or break the drill pipe, or trip the drill pipe, the drilling fluid is continuously circulated through the normally closed bypass valve 9, and the normally open main valve 5 above the normally closed bypass valve 9 is automatically closed by utilizing the pressure difference of the circulating drilling fluid.

[0081] Obviously, the above embodiments are merely examples for clarity of explanation and are not intended to limit the implementation methods. Those skilled in the art will readily appreciate that other variations or modifications can be made based on the above descriptions. It is not necessary and impossible to enumerate all implementation methods here. Obvious variations or modifications derived therefrom remain within the scope of protection of the present invention.

Claims

1. A continuous circulation drilling tripping mud channel switching valve, characterized by: The continuous circulation drilling tripping mud channel switching valve comprises a short-circuit main body (1), a clamping spring (2), a clamping flap (3), a retaining ring (4), a normally open main valve (5), a normally closed bypass valve (9) and a pressure block (19), wherein the clamping flap (3) is arranged at a positioning clamping groove of the short-circuit main body (1), the clamping spring (2) is clamped in a limiting groove (301) of the clamping flap (3), and the retaining ring (4) is arranged on the inner wall of the clamping flap (3) below the clamping spring (2); the normally open main valve (5) and the short-circuit main body (1) are coaxially arranged and installed, the normally closed bypass valve (9) is arranged on the side wall of the short-circuit main body (1) located below the normally open main valve (5), and the position of the normally closed bypass valve (9) on the side wall of the short-circuit main body (1) is limited by the pressure block (19); The normally open main valve (5) comprises a main valve core (6), a movable slider (7) and a main valve body (8); the main valve core (6) and the movable slider (7) are both coaxially arranged and installed with the main valve body (8); The normally closed bypass valve (9) comprises a bypass valve seat (10), a bypass valve core (11), a plug core (12), a plug head (13), a double-flap check valve (14) and a pin shaft (15); the bypass valve core (11) is installed in the bypass valve seat (10) through a threaded connection, the plug core (12) is installed in the plug head (13) coaxially through a threaded connection, and the plug head (13) is installed in the bypass valve core (11) through a threaded connection; The double-flap check valve (14) comprises a positioning valve seat (16), a torsion spring (17) and a valve flap (18); the valve flaps (18) are two in number and are connected to the positioning valve seat (16) via the torsion spring (17); the positioning valve seat (16) of the double-flap check valve (14) is hinged to the bypass valve seat (10) via a pin shaft (15); The short-circuit main body (1) is cylindrical, with an upper hole diameter larger than a lower hole diameter, and is internally provided with a main circulation pipeline, a bypass circulation pipeline, a connecting female buckle (101), a connecting groove (102), and a connecting male buckle (103); the upper end is connected to the drill pipe via the connecting female buckle (101), and the lower end is connected to the drill pipe via the connecting male buckle (103); the pressure block (19) is connected to the normally closed bypass valve (9) on the side wall of the short-circuit main body (1) via the connecting groove (102); The main valve core (6) is provided with a limiting protrusion (601), a positioning groove (602) and a sliding groove (603); the main valve body (8) is installed and matched with the main valve core (6) through the limiting protrusion (601), and the movable slider (7) is positioned relative to the main valve core (6) through the positioning groove (602); The movable slider (7) is a cup-shaped body, with a positioning protrusion (701) on the upper part, which cooperates with the positioning groove (602) on the main valve core (6) to realize the position limitation of the movable slider (7) when the normally open main valve (5) is closed. The side wall is evenly distributed with multiple fluid channels (702) and slideways (703). The slideways (703) cooperate with the slide grooves (603) on the main valve core (6) so that the movable slider (7) can move along the slide grooves (603) on the main valve core (6). The bottom is provided with an arc-shaped protrusion (704), and the size of the arc-shaped protrusion (704) is the same as the inner diameter of the main valve core (6); The main valve body (8) is a variable diameter body with a wide mouth on the lower side, which can slow down the flow rate of the circulating drilling fluid and disperse the impact force of the circulating drilling fluid, avoid the generation of turbulence or eddy current, and reduce the wear or erosion of the pipeline wall. The main valve body (8) is provided with a sealing groove I (801) and a trapezoidal protrusion (802); the sealing between the main valve body (8) and the short-circuit body (1) is achieved by adding a sealing ring in the sealing groove I (801), and the position of the movable slider (7) is limited when the normally open main valve (5) is opened by the trapezoidal protrusion (802); The bypass valve seat (10) is provided with a threaded hole I (1001), a threaded hole II (1002), a sealing groove II (1003), a sealing groove III (1004) and a sealing groove IV (1005); the threaded hole I (1001) on the bypass valve seat (10) and the connecting groove (102) are installed on the side wall of the short-circuit body (1) through a pressing block (19); the threaded hole II (1002) on the bypass valve seat (10) and the positioning valve seat (16) on the double-flap check valve (14) are connected through a pin shaft (15); the bypass valve seat (10) is sealed with the bypass valve core (11) by adding a sealing ring in the sealing groove II (1003), is sealed with the short-circuit body (1) by adding a sealing ring in the sealing groove III (1004), and is formed into a contact seal with the valve disc by adding a sealing ring in the sealing groove IV (1005); The plugging core (12) is provided with a sealing groove V (1201), and a sealing ring is added in the sealing groove V (1201) to achieve sealing with the plug (13); The plug (13) is provided with a through hole (1301), a sealing groove VI (1302) and a glue coating groove (1303); the through hole (1301) needs to be kept open to reduce the air pressure; a sealing ring is provided in the sealing groove VI (1302) to achieve sealing with the bypass valve core (11), and glue is applied in the glue coating groove (1303) to achieve contact sealing with the end of the plug core (12); The positioning valve seat (16) is provided with a support shaft I (1601) and a support shaft II (1602); the torsion spring (17) is two in number and is installed on the support shaft II (1602), with one end connected to the support shaft I (1601) and the other end connected to the torsion spring groove (1802) on the valve disc (18); The valve flap (18) is provided with a mounting boss (1801) and a torsion spring groove (1802), and a rubber layer is provided on the edge; the valve flap (18) is mounted on the support shaft II (1602) via the mounting boss (1801).

2. The continuous circulation drilling tripping mud channel switching valve according to claim 1, characterized in that: The positioning valve seat (16) is hinged to the bypass valve seat (10) through a pin shaft (15) and adopts an articulated rod installation method, which is convenient to install and easy to replace.

3. The continuous circulation drilling tripping mud channel switching valve according to claim 1, characterized in that: The valve flap (18) is tightly pressed against the bypass valve seat (10) under the action of the torsion spring (17), and a contact seal is formed between the valve flap (18) and the bypass valve seat (10).

4. The continuous circulation drilling tripping mud channel switching valve according to claim 1, characterized in that: The plug core (12) is mounted on the plug (13) through a threaded connection, the plug (13) is mounted on the bypass valve core (11) through a threaded connection, the bypass valve core (11) is mounted on the bypass valve seat (10) through a threaded connection, and the bypass valve seat (10) is mounted on the side wall of the short-circuit body (1) through a threaded connection.

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