Continuous circulation well drilling tripping mud channel switching valve

Abstract

The invention discloses a tripping mud channel switching valve for continuous circulation drilling. The tripping mud channel switching valve 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 whole 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 oil drilling tools, and in particular relates to a continuous circulation drilling tripping mud channel switching valve used in the continuous circulation drilling technology. Background technology:

[0002] During the drilling operation, when connecting a single root or column and when pulling out and drilling, the pump will stop or start, which will cause the bottom hole pressure to fluctuate, thus bringing a series of complex problems downhole. Continuous circulation drilling technology is proposed to solve this problem. This technology mainly uses a continuous circulation valve to close the positive circulation channel when connecting and unloading a single root or column, and open the bypass circulation channel of the continuous circulation valve for continuous circulation, thereby maintaining a constant drilling circulation displacement and equivalent density, and preventing accidents or complex situations such as well wall collapse, overflow, sand settling and drill bit jamming caused by stopping circulation when connecting and unloading a single root or column.

[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 structures of the three-way ball valve and the ball valve-plate valve combination 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, and the degree of automation response is low and it is easy to cause the defect of slow response speed.

[0004] The current double-plate valve structure uses a return spring to open and close the main valve plate. However, since the return spring is exposed to the erosion of the circulating drilling fluid for a long time, there are problems such as the central valve plate is easily eroded, resulting in seal failure, the return spring is damaged by long-term force, and the inability to insert the drilling inclination measurement tool into the drill string, which affects the safety of the operation. In addition, the seal of the bypass valve is exposed to the erosion of the circulating drilling fluid, which is prone to seal failure and reduces the service life of the bypass valve.

[0005] Chinese patent 2011101301394 discloses an uninterrupted circulation short circuit for oil drilling and a continuous circulation mud method thereof, wherein 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 buckle, unbuckling and tripping, the mud is circulated uninterruptedly from the lateral normally closed check valve. Although the pressure of the circulating mud is also used to automatically close the automatic center gate valve, when the automatic center gate valve is in the open state, the position of the gate valve cover is parallel to the axis of the circulation channel, so the pressure change on both sides of the center gate valve is not obvious and the response speed is slow. Problem: Since the gate valve cover is fixed to the valve cylinder only by a single pin shaft, when the pressure on both sides of the center gate valve changes suddenly, 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 increase the erosion effect on the pipe wall, causing the pipe wall to wear more severely; 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 sealing 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 which utilizes drilling fluid pressure to achieve rapid switching between a positive circulation channel and a bypass circulation channel.

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

[0008] A continuous circulation drilling tripping mud channel switching valve, characterized in that: the continuous circulation drilling tripping mud channel switching valve comprises a short-circuit body, a clamping spring, a clamping flap, a retaining ring, a normally open main valve, a normally closed bypass valve and a pressure block, wherein the clamping flap is arranged at a positioning clamping groove of the short-circuit body, the clamping spring is clamped in a limiting groove of the clamping flap, and the retaining ring is arranged on an inner wall of the clamping flap below the clamping spring; the normally open main valve is coaxially arranged and installed with the short-circuit body, 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 comprises 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 installed in the plugging core coaxially through a threaded connection, and the plugging core 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 flap; the valve flaps are two in number and are connected to the positioning valve seat via a torsion spring; the positioning valve seat of the double-flap check valve is hinged on the bypass valve seat via a pin shaft;

[0012] The short-circuit main body is cylindrical, the diameter of the upper hole is larger than the diameter of the lower hole, and a main circulation pipeline, a bypass circulation pipeline, a connecting box, a connecting groove and a connecting pin are arranged inside; the upper end is connected to the drill pipe through the connecting box, and the lower end is connected to the drill pipe through the connecting pin, and the pressure block realizes the position limitation of the normally closed bypass valve on the side wall of the short-circuit main 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 limited in position with 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, which cooperates with the positioning groove on the main valve core to realize the position limitation of the movable slider when the normally open main valve is closed. The side wall is evenly distributed with multiple fluid channels and slideways, and the slideways cooperate with the slide grooves on the main valve core so that the movable slider can move on the main valve core along the slide grooves. The bottom has an arc-shaped protrusion, and the size of the arc-shaped protrusion 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 at the bottom, 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 current, and reduce the wear or erosion of the pipeline wall. The main valve body is provided with a sealing groove I and a trapezoidal protrusion; the sealing between the main valve body and the short-circuit body is achieved by adding a sealing ring in the sealing groove I, and the position of the movable slider is limited when the normally open main valve is opened by the trapezoidal protrusion;

[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 installed on the side wall of the short-circuit body through 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 through 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 in 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, one end of which is connected to the support shaft I and the other end is connected to the torsion spring groove on the valve disc;

[0020] The valve flap is provided with a mounting boss and a torsion spring groove, and a rubber layer is provided on the edge; the valve flap 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 an articulated rod installation method is adopted, 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, and change it to enter the short-circuit body through the normally closed bypass valve on the side wall of the short-circuit body for circulating drilling fluid;

[0026] S2: Increase the pressure of the circulating drilling fluid entering the short-circuit body from 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, so as to realize the automatic closing of the normally open main valve coaxially installed with the short-circuit body;

[0027] S3: Open the positive circulation channel and close the bypass circulation channel to reduce the pressure of the drilling fluid circulating in 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, and 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 buckle, detach the buckle and trip the drill, the drilling fluid is circulated continuously 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 reset spring, which effectively improves the 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 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 slideway on the main valve core can limit the position of the movable slider, which improves the working stability and avoids the axial rotation of the movable slider when it is 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 cycle drilling operations under various drilling conditions, and has good continuity and is not easily 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 It is a structural schematic diagram of the retaining ring of the present invention;

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

[0041] Figure 6 This is a schematic diagram of the structure 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 a main valve core of the present invention;

[0044] Fig. 9 A schematic structural diagram of a movable slider of the present invention;

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

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

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

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

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

[0050] Fig.15 A schematic structural diagram of a double-flap check valve of the present invention;

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

[0052] Fig.17 A schematic structural diagram of a torsion spring of the present invention;

[0053] Fig.18 A schematic diagram of the structure of the valve flap 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 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 in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are 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 "center", "up", "down", "left", "right", "vertical", "horizontal", "inside", "outside", etc. are directions or positional relationships based on the drawings, which are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as limiting the present invention. In addition, "first" and "second" are only used for descriptive purposes and cannot be understood as indicating or implying relative importance.

[0057] In the description of the present invention, it should be noted that, unless otherwise clearly specified and limited, "installation", "connection" and "connection" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or it can be indirectly connected through an intermediate medium, or it can be the internal communication of two components. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0058] like Figures 1 to 18As 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 core 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 core 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 flap 18; the valve flap 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 on the bypass valve seat 10 via the pin 15;

[0062] In this embodiment, the short-circuit body 1 is cylindrical, the diameter of the upper channel is larger than the diameter of the lower channel, and a main circulation pipeline, a bypass circulation pipeline, a connecting female buckle 101, a connecting groove 102 and a connecting male buckle 103 are arranged inside; the upper end is connected to the drill pipe through the connecting female buckle 101, and the lower end is connected to the drill pipe through the connecting male buckle 103. The pressure block 19 realizes the position limitation of 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 slide 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 with the main valve core 6 through the positioning groove 602;

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

[0065] In this embodiment, the main valve body 8 is a reducer with a wide mouth at the bottom, 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 current, and reduce the wear or erosion of the pipeline wall. The main valve body 8 is provided with a sealing groove Ⅰ801 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 Ⅰ801, and the position of the movable slider 7 is limited when the normally open main valve 5 is opened by the trapezoidal protrusion 802;

[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 installed on the side wall of the short-circuit body 1 through a pressing block 19, the threaded hole II1002 on the bypass valve seat 10 and the positioning valve seat 16 on the double-flap check valve 14 are connected through 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, and a sealing ring is added in the sealing groove VI 1302 to achieve sealing with the bypass valve core 11, and glue is applied in the glue coating groove 1302 to achieve contact sealing with the end of the plug core 13;

[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 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 flap 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 11 through the pin shaft 15, and adopts the installation mode of hinged rod, 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 11 under the action of the torsion spring 17 , and a contact seal is formed between the valve flap 18 and the bypass valve seat 11 .

[0073] In this embodiment, the plug core 12 is installed on the plug 13 by threaded connection, the plug 13 is installed on the bypass valve core 11 by threaded connection, the bypass valve core 11 is installed on the bypass valve seat 10 by threaded connection, and the bypass valve seat 10 is installed on the side wall of the short-circuit body 1 by 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, and change it to enter the short-circuit body through the normally closed bypass valve 9 on the side wall of the short-circuit body 1 as circulating drilling fluid;

[0076] S2: Increase the pressure of the circulating drilling fluid entering the short-circuit body 1 from 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, so that the normally open main valve 5 coaxially arranged and installed with the short-circuit body 1 is automatically closed;

[0077] S3: Open the positive circulation channel, close the bypass circulation channel, and reduce the pressure of the 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 for circulation; the valve flap 18 is automatically closed under the action of the torsion spring 17, so that the normally closed bypass valve 9 on the side wall of the short-circuit body 1 is closed;

[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, and the circulating drilling fluid flows out through the fluid channel 702 on the side wall of the movable slider 7, so that 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, unbuck and trip the drill pipe, the drilling fluid is circulated continuously 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 clear explanation, and are not intended to limit the implementation methods. For ordinary technicians in the relevant field, other different forms of changes or modifications can be made based on the above description. It is not necessary and impossible to list all the implementation methods here. The obvious changes or modifications derived from them are still within the protection scope of the invention.

Claims

1. A continuous circulation drilling tripping mud channel switching valve, characterized in that: The short-circuit body (1) comprises 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 a positioning clamping groove of the short-circuit 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) is coaxially arranged and installed with the short-circuit body (1), 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); 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 coaxially in the plug head (13) 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 flap (18) is in two pieces 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 on the bypass valve seat (10) via a pin shaft (15); The short-circuit body (1) is cylindrical, the diameter of the upper hole is larger than the diameter of the lower hole, and is 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) inside; the upper end is connected to the drill pipe through the connecting female buckle (101), and the lower end is connected to the drill pipe through the connecting male buckle (103); the pressing block (19) is used to define the position of the normally closed bypass valve (9) on the side wall of the short-circuit body (1) through the connecting groove (102); The main valve core (6) is provided with a limiting protrusion (601), a positioning groove (602) and a slide 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 slide block (7) is positioned relative to the main valve core (6) through the positioning groove (602); The movable slider (7) is a cup-shaped body, and a positioning protrusion (701) is provided on the upper part. By cooperating with the positioning groove (602) on the main valve core (6), the position of the movable slider (7) is limited when the normally open main valve (5) is closed. The side wall is evenly distributed with multiple fluid channels (702) and slideways (703). The slideway (703) cooperates with the slide groove (603) on the main valve core (6) so that the movable slider (7) can move on the main valve core (6) along the slide groove (603). The bottom is provided with an arc-shaped protrusion (704), and the size of the arc-shaped protrusion (704) is equal to the inner diameter of the main valve core (6); The main valve body (8) is a reducer with a wide opening at the bottom, 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 current, and reduce wear or erosion on the pipeline 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); and the trapezoidal protrusion (802) is used to limit the position of the movable slider (7) when the normally open main valve (5) is opened; 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) via 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 via 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 contact-sealed 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 added in the sealing groove VI (1302) to achieve sealing with the bypass valve core (11), and glue is applied in the glue coating groove (1302) to achieve contact sealing with the end of the plug core (13); 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), one end of which is connected to the support shaft I (1601) and the other end of which is 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. A 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 (11) via a pin shaft (15) and adopts a hinged rod installation method, which is convenient to install and easy to replace.

3. A 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 (11) under the action of the torsion spring (17), and a contact seal is formed between the valve flap (18) and the bypass valve seat (11).

4. A continuous circulation drilling tripping mud channel switching valve according to claim 1, characterized in that: The plugging 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.

5. The continuous circulation drilling tripping mud channel switching valve according to claim 1, characterized in that: The method for switching the continuous circulation drilling tripping mud channel comprises the following steps: 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), and change it to enter the short-circuit body through the normally closed bypass valve (9) on the side wall of the short-circuit body (1) for use as circulating drilling fluid; S2: increasing 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 realizing the automatic closing of the normally open main valve (5) coaxially arranged and installed with the short-circuit body (1); S3: opening the positive circulation channel and closing the bypass circulation channel, reducing the pressure of the 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) for circulating the drilling fluid; the valve flap (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); S4: increasing and restoring 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), and the circulating drilling fluid flows out through the fluid channel (702) on the side wall of the movable slider (7), thereby realizing the automatic opening of the normally open main valve (5); S5: Remove the side circulation pipeline connected to the normally closed bypass valve (9).

6. The continuous circulation drilling tripping mud channel switching valve according to claim 1, characterized in that When it is necessary to disassemble and assemble the drill pipe buckle, unbuck, 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.

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