Downhole while drilling circulation bypass tool and unlimited circulation bypass method

Abstract

This invention relates to the field of circulation bypass tools, specifically a downhole drilling circulation bypass tool and an unlimited circulation bypass method. The former includes a main body, an upper guide sleeve, a lower guide sleeve, a central tube, an indexing sleeve, an activation ball seat, and an isolation ball seat. The main body contains an indexing sleeve, with an upper guide sleeve and a lower guide sleeve located above and below it, respectively, to assist in the indexing sleeve's rotation. The upper and lower guide sleeves are installed at corresponding positions on the main body. A central tube is installed inside the indexing sleeve, with its lower end located below the lower guide sleeve. This invention features a reasonable and compact structure, is easy to use, and utilizes a combination of an upper guide sleeve, an indexing sleeve, and a lower guide sleeve to control the periodic alignment and misalignment of the circulation holes, enabling the tool to switch between different working states. The absence of a ball basket at the bottom shortens the effective length of the drill string, facilitating bottom hole assembly design, wellhead installation, and transportation.

Description

Technical Field

[0001] This invention relates to the field of circulation bypass tools, specifically a downhole drilling circulation bypass tool and an unlimited circulation bypass method. Background Technology

[0002] A circulation bypass tool is a surface-controlled bypass tool that enables multiple alternating forward and lateral (bypass) cycles for drilling-while-drilling plugging and high-volume well flushing. Based on the number of activations, tools can be categorized as finite-use or unlimited-use tools. Finite-use tools have their activation count limited by the length of the ball basket, which often restricts their use in complex conditions. In finite-use tools, the functional ball falls into the lower basket after completing its mechanical action, affecting the tool's internal passageway. With the increasing development of deep, ultra-deep, and complex well processes, drilling-while-drilling plugging and high-volume well flushing technologies demand circulation bypass tools with more activations, simpler operation, and higher stability. Summary of the Invention

[0003] This invention provides a downhole drilling circulation bypass tool and an unlimited circulation bypass method, which overcomes the shortcomings of the prior art. It can effectively solve the problem that the functional ball of the existing circulation bypass tool falls into the lower ball basket after completing the mechanical action, affecting the internal passage of the tool.

[0004] One of the technical solutions of the present invention is achieved through the following measures: a downhole drilling circulation bypass tool, comprising a body, an upper guide sleeve, a lower guide sleeve, a central tube, an indexing sleeve, an activation ball seat, and an isolation ball seat. The body is provided with an indexing sleeve. An upper guide sleeve and a lower guide sleeve, which can cooperate with the indexing sleeve to turn, are respectively provided on the upper and lower sides of the indexing sleeve. The upper and lower guide sleeves are respectively installed together with the corresponding positions of the body. A central tube is installed inside the indexing sleeve. The lower end of the central tube is located below the lower guide sleeve. A mounting platform is provided on the lower inner side of the body. A cylindrical helical compression spring is provided between the lower end of the central tube and the mounting platform. An activation ball seat and an isolation ball seat are respectively installed in the central tube corresponding to the upper and lower positions of the indexing sleeve. An inner circulation hole and a middle circulation hole are respectively provided on the central tube and the indexing sleeve corresponding to the position between the activation ball seat and the isolation ball seat. An outer circulation hole is provided on the body corresponding to the position below the middle circulation hole.

[0005] The following are further optimizations and / or improvements to the above-mentioned technical solution:

[0006] The upper guide sleeve has ten top guide keys evenly distributed around its circumference at its lower end. Five long slots and five short slots are formed between adjacent top guide keys, with the long and short slots alternating. The indexing sleeve has five upper guide keys evenly distributed around its circumference at its upper end. The upper guide keys are located in the long slots. The indexing sleeve has ten middle guide keys evenly distributed around its circumference at its lower end. The middle guide keys form middle keyways between them. The lower guide sleeve has ten lower guide keys evenly distributed around its circumference at its upper end. The lower guide keys form lower keyways between them. The middle guide keys can mate with the lower keyways, and the middle keyways can mate with the lower guide keys. The ends of the top guide keys, upper guide keys, middle guide keys, and lower guide keys are all provided with 45-degree guide surfaces.

[0007] The central tube at the position between the indexing sleeve and the lower guide sleeve can have waist-shaped holes that are evenly distributed around the circumference.

[0008] The aforementioned activation spheres and isolation spheres can be made of biodegradable aluminum-magnesium alloy.

[0009] Both the upper and lower guide sleeves can be fixedly installed together with the body by means of pins. An O-ring is provided between the pin and the body. A support platform is provided on the inner side of the body corresponding to the lower end of the lower guide sleeve. The lower end of the lower guide sleeve is located on the upper side of the support platform. An O-ring is provided between the activation ball seat and the central tube. A sealing ring is provided between the isolation ball seat and the central tube. An O-ring is provided between the central tube corresponding to the activation ball seat and the body. At least one U-shaped sealing ring is provided between the body and the indexing sleeve at intervals above and below the external circulation hole.

[0010] The second technical solution of the present invention is achieved through the following measures: an infinitely cyclic bypass method includes a high-volume well flushing method and a leakage plugging method:

[0011] High-volume well washing method: (1) Activation ball is put into the wellhead. The degradation time of the activation ball must be greater than the time of pumping to the ball seat;

[0012] (2) Pump the activation ball, reduce the pumping flow rate and slowly press it before pumping it into place;

[0013] (3) The activation ball pushes the central tube and the indexing sleeve downwards. The guide surface of the guide key in the indexing sleeve contacts the guide surface of the lower guide key in the lower guide sleeve. The hydraulic pressure pushes the indexing sleeve to rotate downwards to the bottom. At this time, the circulation hole in the indexing sleeve and the outer circulation hole on the body are axially misaligned and circumferentially misaligned.

[0014] (4) Continue to pressurize to 20MPa. The activation ball forces the activation ball seat to undergo plastic deformation. The hydraulic pressure knocks the activation ball off. The activation ball passes through the activation ball seat and the isolation ball seat continuously and falls into the lower drill bit, waiting for degradation.

[0015] (5) The cylindrical spiral compression spring pushes the central tube and the indexing sleeve to rotate upward. The guide surface of the guide key on the indexing sleeve contacts the guide surface of the guide key at the top of the upper guide sleeve. The cylindrical spiral compression spring pushes the indexing sleeve to rotate 18°. The guide key on the indexing sleeve enters the short groove of the upper guide sleeve. The circulation hole in the indexing sleeve is aligned with the external circulation hole on the body, and the bypass flow channel is opened.

[0016] (6) At this time, the drilling fluid in the drill string can be circulated through the bypass channel and the drill bit water hole to carry out large-volume well washing operation. The flow channel ratio design allows the flow rate ratio of the bypass and drill bit water hole channels to be 3:1 to 4:1.

[0017] (7) After the large-volume well washing operation is completed, an activation ball is put into the wellhead. The degradation time of the activation ball must be longer than the time it takes to pump to the ball seat.

[0018] (8) Pump the activation ball, reduce the pumping flow rate and slowly press it before pumping it into place;

[0019] (9) The activation ball pushes the central tube and the indexing sleeve downwards. The guide surface of the guide key in the indexing sleeve contacts the guide surface of the lower guide key in the lower guide sleeve. The hydraulic pressure pushes the indexing sleeve to rotate and descend to the bottom. At this time, the circulation hole in the indexing sleeve and the outer circulation hole on the body are axially misaligned and circumferentially misaligned again.

[0020] (10) Continue to pressurize to 20MPa. The activation ball forces the activation ball seat to undergo plastic deformation. The hydraulic pressure knocks the activation ball off. The activation ball passes through the activation ball seat and the isolation ball seat continuously and falls into the lower drill bit, waiting for degradation.

[0021] (11) The cylindrical spiral compression spring pushes the central tube and the indexing sleeve to move upward. The guide surface of the guide key on the indexing sleeve contacts the guide surface of the guide key at the top of the upper guide sleeve. The cylindrical spiral compression spring pushes the indexing sleeve to rotate 18°. The guide key of the indexing sleeve enters the long groove of the upper guide sleeve, and the tool returns to its initial state.

[0022] Leak sealing methods:

[0023] (1) Activation balls are put into the wellhead, and the degradation time of the activation balls must be greater than the time it takes to pump them to the ball seat;

[0024] (2) Pump the activation ball, reduce the pumping flow rate and slowly press it before pumping it into place;

[0025] (3) The activation ball pushes the central tube and the indexing sleeve downwards. The guide surface of the guide key in the indexing sleeve contacts the guide surface of the lower guide key in the lower guide sleeve. The hydraulic pressure pushes the indexing sleeve to rotate downwards to the bottom. At this time, the circulation hole in the indexing sleeve and the outer circulation hole on the body are axially misaligned and circumferentially misaligned.

[0026] (4) Continue to pressurize to 20MPa. The activation ball forces the activation ball seat to undergo plastic deformation. The hydraulic pressure knocks the activation ball off. The activation ball passes through the activation ball seat and the isolation ball seat continuously and falls into the lower drill bit, waiting for degradation.

[0027] (5) The cylindrical spiral compression spring pushes the central tube and the indexing sleeve to move upward. The guide surface of the indexing sleeve guide key contacts the guide surface of the upper guide sleeve guide key. The cylindrical spiral compression spring pushes the indexing sleeve to rotate 18°. The indexing sleeve guide key enters the short groove of the upper guide sleeve. The circulation hole in the indexing sleeve is aligned with the external circulation hole on the body, and the bypass flow channel is opened.

[0028] (6) Insert isolation balls into the wellhead. The degradation time of the isolation balls must be longer than the estimated time for plugging operations.

[0029] (7) Pump the isolation ball. Before pumping it into place, reduce the pumping flow rate. Due to size limitations, the isolation ball passes through the activation ball seat and falls into the isolation ball seat. Slowly press it and control the pressure so as not to push the indexing sleeve downward again.

[0030] (8) Perform plugging operation. If the plugging operation takes longer than the estimated time, drop the isolation ball again from the wellhead. After the first isolation ball degrades, it will fall back into the ball seat to isolate the drilling fluid.

[0031] (9) After the plugging operation is completed, an activation ball is put into the wellhead. The degradation time of the activation ball must be longer than the time it takes to be pumped to the ball seat.

[0032] (10) Pump the activation ball, reduce the pumping flow rate and slowly press it before pumping it into place;

[0033] (11) The activation ball pushes the central tube and the indexing sleeve downwards. The guide surface of the guide key in the indexing sleeve contacts the guide surface of the guide key in the lower guide sleeve. The hydraulic pressure pushes the indexing sleeve to rotate downwards to the bottom. At this time, the circulation hole in the indexing sleeve and the outer circulation hole on the body are axially misaligned and circumferentially misaligned again.

[0034] (12) Continue to pressurize to 20MPa. The activation ball forces the activation ball seat to undergo plastic deformation. The hydraulic pressure knocks the activation ball and the isolation ball off. The activation ball passes through the activation ball seat and the isolation ball seat continuously and falls into the lower drill bit, waiting for degradation.

[0035] (13) The cylindrical spiral compression spring pushes the central tube and the indexing sleeve to move upward. The guide surface of the guide key on the indexing sleeve contacts the guide surface of the guide key at the top of the upper guide sleeve. The cylindrical spiral compression spring pushes the indexing sleeve to rotate 18°. The guide key on the indexing sleeve enters the long groove of the upper guide sleeve, and the tool returns to its initial state.

[0036] The invention has a reasonable and compact structure and is easy to use. It adopts a combination of upper guide sleeve, indexing sliding sleeve and lower guide sleeve to control the periodic alignment and misalignment of the circulation hole to realize the conversion between different working states of the tool. There is no ball basket at the bottom, which can shorten the effective length of the drill string, and bring convenience to the bottom drill string assembly design, wellhead installation and transportation. Attached Figure Description

[0037] Appendix Figure 1 This is a schematic diagram of the front cross-sectional structure according to an embodiment of the present invention.

[0038] Appendix Figure 2 For the appendix Figure 1 Enlarged cross-sectional view of the upper guide sleeve and indexing sleeve.

[0039] The codes in the attached diagram are as follows: 1 is the main body, 2 is the upper guide sleeve, 3 is the lower guide sleeve, 4 is the central tube, 5 is the indexing sleeve, 6 is the activation ball, 7 is the activation ball seat, 8 is the isolation ball, 9 is the isolation ball seat, 10 is the mounting platform, 11 is the cylindrical helical compression spring, 12 is the inner circulation hole, 13 is the middle circulation hole, 14 is the outer circulation hole, 15 is the long groove, 16 is the short groove, 17 is the middle guide key, 18 is the upper guide key, 19 is the guide surface, 20 is the oblong hole, 21 is the pin, 22 is the O-ring seal, 23 is the U-ring seal, and 24 is the lower guide key. Detailed Implementation

[0040] The present invention is not limited to the following embodiments, and the specific implementation can be determined according to the technical solution of the present invention and the actual situation.

[0041] In this invention, for ease of description, the description of the relative positions of the components is based on the appendix to the specification. Figure 1 The layout is described using a diagrammatic method, such as front, back, top, bottom, left, right, etc. The positional relationships are determined based on the layout direction of the attached diagram in the instruction manual.

[0042] The present invention will be further described below with reference to embodiments and accompanying drawings:

[0043] Example 1: As shown in the attached document Figure 1 , 2As shown, the downhole circulating bypass tool includes a body 1, an upper guide sleeve 2, a lower guide sleeve 3, a central tube 4, an indexing sleeve 5, an activation ball seat 7, and an isolation ball seat 9. The indexing sleeve 5 is installed inside the body 1. The upper guide sleeve 2 and the lower guide sleeve 3, which can cooperate with the indexing sleeve 5 to rotate, are respectively provided on the upper and lower sides of the indexing sleeve 5. The upper guide sleeve 2 and the lower guide sleeve 3 are installed together with the corresponding positions of the body 1. The central tube 4 is installed inside the indexing sleeve 5, and the lower end of the central tube 4 is located below the lower guide sleeve 3. The lower inner side of the main body 1 is provided with a mounting platform 10. A cylindrical helical compression spring 11 is provided between the lower end of the central tube 4 and the mounting platform 10. An activation ball seat 7 and an isolation ball seat 9 are respectively installed in the central tube 4 at the upper and lower positions of the indexing sleeve 5. The central tube 4 and the indexing sleeve 5 at the position between the activation ball seat 7 and the isolation ball seat 9 are respectively provided with an inner circulation hole 12 and a middle circulation hole 13. The main body 1 at the position below the middle circulation hole 13 is provided with an outer circulation hole 14 that is connected inside and outside.

[0044] The main body 1, the indexing sleeve 5, and the central tube 4 are each equipped with five identical circulation holes. In the initial state, the circulation hole 13 in the indexing sleeve 5 and the circulation hole 12 in the central tube 4 are located directly above the outer circulation hole 14 of the main body 1. Under the guidance of the guide key and guide surface 19 of the upper guide sleeve 2 and the lower guide sleeve 3, the indexing sleeve 5 can periodically perform axial reciprocating motion and circumferential rotation, so that the circulation hole 13 in the indexing sleeve 5 and the circulation hole 12 in the central tube 4 are periodically aligned and misaligned with the outer circulation hole 14 of the main body 1.

[0045] This invention uses an upper guide sleeve 2, an indexing sleeve 5, and a lower guide sleeve 3 to control the periodic alignment and misalignment of the circulation holes, thereby enabling the tool to switch between different working states. The upper guide sleeve 2, the indexing sleeve 5, and the lower guide sleeve 3 can all be processed by wire cutting. Compared with the traditional index pin 21 and index sleeve control method, the processing difficulty and cost are greatly reduced. This invention has no ball basket at the bottom, which can shorten the effective length of the drill string, bringing convenience to the bottom drill string assembly design, wellhead installation, and transportation.

[0046] Multiple tools can be connected in the drill string using ball-and-ball seats of different sizes, allowing for selective activation and deactivation of the tools.

[0047] The above-mentioned downhole circulating bypass tools can be further optimized and / or improved according to actual needs:

[0048] Example 2: As shown in the attached document Figure 1 , 2As shown, ten top guide keys are evenly distributed along the circumference of the lower end of the upper guide sleeve 2. Five long grooves 15 and five short grooves 16 are formed between adjacent top guide keys. The long grooves 15 and short grooves 16 are alternately arranged. Five upper guide keys 18 are evenly distributed along the circumference of the upper end of the indexing sleeve 5. The upper guide keys 18 are located in the long grooves 15. Ten middle guide keys 17 are evenly distributed along the circumference of the lower end of the indexing sleeve 5. Middle key grooves are formed between the middle guide keys 17. Ten lower guide keys 24 are evenly distributed along the circumference of the upper end of the lower guide sleeve 3. Lower key grooves are formed between the lower guide keys 24. The middle guide keys 17 can cooperate with the lower key grooves, and the middle key grooves can cooperate with the lower guide keys 24. The ends of the top guide keys, upper guide keys 18, middle guide keys 17 and lower guide keys 24 are all provided with 45-degree guide surfaces 19.

[0049] In the initial state, the upper guide key 18 is located inside the long slot 15, and the middle guide key 17 is located above the lower guide key 24.

[0050] Example 3: As shown in the attached document Figure 1 As shown, the central tube 4, corresponding to the position between the indexing sleeve 5 and the lower guide sleeve 3, has waist-shaped holes 20 evenly distributed around its circumference. The central tube 4 has only waist-shaped holes 20 for flow channels, which can prevent the indexing sleeve 5 from forming a hydraulic dead cavity with the lower guide sleeve 3 during the downward movement.

[0051] Example 4: As shown in the appendix Figure 1 As shown, the activation ball 6 and isolation ball 8 are made of biodegradable aluminum-magnesium alloy. The biodegradable material will not block the channels inside the main body 1, allowing the tool to be activated and deactivated an unlimited number of times.

[0052] Example 5: As shown in the attached document Figure 1 As shown, the upper guide sleeve 2 and the lower guide sleeve 3 are both fixedly installed to the body 1 by pins 21. An O-ring 22 is provided between the pin 21 and the body 1. A support platform is provided on the inner side of the body 1 corresponding to the lower end of the lower guide sleeve 3. The lower end of the lower guide sleeve 3 is located on the upper side of the support platform. An O-ring 22 is provided between the activation ball seat 7 and the central tube 4. A sealing ring is provided between the isolation ball seat 9 and the central tube 4. An O-ring 22 is provided between the central tube 4 corresponding to the position of the activation ball seat 7 and the body 1. At least one U-shaped sealing ring 23 is provided vertically between the body 1 and the indexing sleeve 5 at positions above and below the external circulation hole 14. The sealing rings are used to seal and prevent drilling fluid from affecting the movement of the components.

[0053] Example 6: As attached Figure 1 , 2 As shown, the infinite-cycle bypass method includes high-volume well flushing and leakage plugging methods:

[0054] Large-volume well washing method: (1) Activation ball 6 is put into the wellhead. The degradation time of activation ball 6 must be greater than the pumping time to the ball seat;

[0055] (2) Pump the activation ball 6, reduce the pumping flow rate and slowly press it before pumping it into place;

[0056] (3) Activate ball 6 pushes the center tube 4 and the indexing sleeve 5 downward. The guide surface 19 of guide key 17 in indexing sleeve 5 contacts the guide surface 19 of guide key 24 in lower guide sleeve 3. Hydraulically pushes indexing sleeve 5 to rotate downward to the bottom. At this time, the circulation hole 13 in indexing sleeve 5 and the outer circulation hole 14 on the body 1 are axially displaced and circumferentially misaligned.

[0057] (4) Continue to pressurize to 20MPa. The activation ball 6 forces the activation ball seat 7 to undergo plastic deformation. The hydraulic pressure knocks the activation ball 6 off. The activation ball 6 passes through the activation ball seat 7 and the isolation ball seat 9 and falls into the lower drill bit, waiting for degradation.

[0058] (5) The cylindrical spiral compression spring 11 pushes the central tube 4 and the indexing sleeve 5 to rotate upward. The guide surface 19 of the guide key 18 on the indexing sleeve 5 contacts the guide surface 19 of the guide key at the top of the upper guide sleeve 2. The cylindrical spiral compression spring 11 pushes the indexing sleeve 5 to rotate 18°. The guide key 18 on the indexing sleeve 5 enters the short groove 16 of the upper guide sleeve 2. The circulation hole 13 in the indexing sleeve 5 is aligned with the external circulation hole 14 on the body 1, and the bypass flow channel is opened.

[0059] (6) At this time, the drilling fluid in the drill string can be circulated through the bypass channel and the drill bit water hole to carry out large-volume well washing operation. The flow channel ratio design allows the flow rate ratio of the bypass and drill bit water hole channels to be 3:1 to 4:1.

[0060] (7) After the large-volume well washing operation is completed, the activation ball 6 is put into the wellhead. The degradation time of the activation ball 6 must be greater than the time it takes to be pumped to the ball seat.

[0061] (8) Pump the activation ball 6, reduce the pumping flow rate and slowly press it before pumping it into place;

[0062] (9) Activate ball 6 pushes central tube 4 and indexing sleeve 5 downward. Guide key 17 guide surface 19 in indexing sleeve 5 contacts guide key 24 guide surface 19 in lower guide sleeve 3. Hydraulic pushes indexing sleeve 5 to rotate downward to the bottom. At this time, circulation hole 13 in indexing sleeve 5 and external circulation hole 14 on body 1 are axially displaced and circumferentially misaligned.

[0063] (10) Continue to pressurize to 20MPa. The activation ball 6 forces the activation ball seat 7 to undergo plastic deformation. The hydraulic pressure knocks the activation ball 6 off. The activation ball 6 passes through the activation ball seat 7 and the isolation ball seat 9 and falls into the lower drill bit, waiting for degradation.

[0064] (11) The cylindrical spiral compression spring 11 pushes the central tube 4 and the indexing sleeve 5 upward. The guide surface 19 of the upper guide key 18 of the indexing sleeve 5 contacts the guide surface 19 of the top guide key of the upper guide sleeve 2. The cylindrical spiral compression spring 11 pushes the indexing sleeve 5 to rotate 18°. The guide key of the indexing sleeve 5 enters the long groove 15 of the upper guide sleeve 2, and the tool returns to its initial state.

[0065] Leak sealing methods:

[0066] (1) Activation ball 6 is put into the wellhead. The degradation time of activation ball 6 must be greater than the time it takes to be pumped to the ball seat.

[0067] (2) Pump the activation ball 6, reduce the pumping flow rate and slowly press it before pumping it into place;

[0068] (3) Activate ball 6 pushes the center tube 4 and the indexing sleeve 5 downward. The guide surface 19 of guide key 17 in indexing sleeve 5 contacts the guide surface 19 of guide key 24 in lower guide sleeve 3. Hydraulically pushes indexing sleeve 5 to rotate downward to the bottom. At this time, the circulation hole 13 in indexing sleeve 5 and the outer circulation hole 14 on the body 1 are axially displaced and circumferentially misaligned.

[0069] (4) Continue to pressurize to 20MPa. The activation ball 6 forces the activation ball seat 7 to undergo plastic deformation. The hydraulic pressure knocks the activation ball 6 off. The activation ball 6 passes through the activation ball seat 7 and the isolation ball seat 9 and falls into the lower drill bit, waiting for degradation.

[0070] (5) The cylindrical spiral compression spring 11 pushes the central tube 4 and the indexing sleeve 5 upward. The guide key 19 of the indexing sleeve 5 contacts the guide key 19 of the upper guide sleeve 2. The cylindrical spiral compression spring 11 pushes the indexing sleeve 5 to rotate 18°. The guide key of the indexing sleeve 5 enters the short groove 16 of the upper guide sleeve 2. The circulation hole 13 in the indexing sleeve 5 is aligned with the external circulation hole 14 on the body 1, and the bypass flow channel is opened.

[0071] (6) Insert isolation ball 8 into the wellhead. The degradation time of isolation ball 8 must be longer than the estimated time for plugging operation.

[0072] (7) Pump the isolation ball 8. Before pumping it into place, reduce the pumping flow rate. Due to size limitations, the isolation ball 8 passes through the activation ball seat 7 and falls into the isolation ball seat 9. Slowly press it and control the pressure so as not to push the indexing sleeve 5 down again.

[0073] (8) Perform plugging operation. If the plugging operation takes longer than the estimated time, the isolation ball 8 is dropped into the wellhead again. After the first isolation ball 8 degrades, it falls back into the ball seat to isolate the drilling fluid.

[0074] (9) After the plugging operation is completed, the activation ball 6 is put into the wellhead. The degradation time of the activation ball 6 must be greater than the time it takes to be pumped to the ball seat.

[0075] (10) Pump the activation ball 6, reduce the pumping flow rate and slowly press it before pumping it into place;

[0076] (11) Activate ball 6 pushes the center tube 4 and the indexing sleeve 5 downward. The guide surface 19 of guide key 17 in indexing sleeve 5 contacts the guide surface 19 of guide key 24 in lower guide sleeve 3. Hydraulically pushes indexing sleeve 5 to rotate downward to the bottom. At this time, the circulation hole 13 in indexing sleeve 5 and the outer circulation hole 14 on the body 1 are axially displaced and circumferentially misaligned again.

[0077] (12) Continue to pressurize to 20MPa. The activation ball 6 forces the activation ball seat 7 to undergo plastic deformation. The hydraulic pressure knocks down the activation ball 6 and the isolation ball 8. The activation ball 6 passes through the activation ball seat 7 and the isolation ball seat 9 and falls into the lower drill bit, waiting for degradation.

[0078] (13) The cylindrical spiral compression spring 11 pushes the central tube 4 and the indexing sleeve 5 upward. The guide surface 19 of the upper guide key 18 of the indexing sleeve 5 contacts the guide surface 19 of the top guide key of the upper guide sleeve 2. The cylindrical spiral compression spring 11 pushes the indexing sleeve 5 to rotate 18°. The upper guide key 18 of the indexing sleeve 5 enters the long groove 15 of the upper guide sleeve 2, and the tool returns to its initial state.

[0079] The above technical features constitute the embodiments of the present invention, which have strong adaptability and implementation effect. Unnecessary technical features can be added or removed according to actual needs to meet the needs of different situations.

Claims

1. A downhole drilling circulation bypass tool, characterized in that... The system includes a main body, an upper guide sleeve, a lower guide sleeve, a central tube, a pivoting sleeve, an activation ball seat, and an isolation ball seat. The main body contains a pivoting sleeve. The upper and lower guide sleeves, respectively, are positioned above and below the pivoting sleeve to facilitate its rotation. The upper and lower guide sleeves are installed at corresponding positions on the main body. A central tube is installed inside the pivoting sleeve, with its lower end located below the lower guide sleeve. A mounting platform is located on the lower inner side of the main body. A cylindrical helical compression spring is positioned between the lower end of the central tube and the mounting platform. Activation ball seats and isolation ball seats are installed in the central tube at the upper and lower positions corresponding to the pivoting sleeve, respectively. Internal circulation holes and middle circulation holes are connected on the central tube and pivoting sleeve at the positions between the activation and isolation ball seats, respectively. The main body below the annular hole has an external circulation hole that runs through both the inside and outside; ten top guide keys are evenly distributed around the circumference of the lower end of the upper guide sleeve, with five long slots and five short slots formed between adjacent top guide keys, and the long and short slots are alternately arranged; five upper guide keys are evenly distributed around the circumference of the upper end of the indexing sleeve, and the upper guide keys are located in the long slots; ten middle guide keys are evenly distributed around the circumference of the lower end of the indexing sleeve, and middle keyways are formed between the middle guide keys; ten lower guide keys are evenly distributed around the circumference of the upper end of the lower guide sleeve, and lower keyways are formed between the lower guide keys; the middle guide keys can mate with the lower keyways, and the middle keyways can mate with the lower guide keys; the ends of the top guide keys, upper guide keys, middle guide keys, and lower guide keys are all provided with 45-degree guide surfaces; the activation ball and the isolation ball are made of biodegradable aluminum-magnesium alloy; The activation ball pushes the central tube and the indexing sleeve downwards, continuing to pressurize to a certain level. The activation ball forces the activation ball seat to undergo plastic deformation, and the hydraulic pressure knocks the activation ball off. The activation ball continuously passes through the activation ball seat and the isolation ball seat, falling into the lower drill string to await degradation. The isolation ball is pumped, and the pumping rate is reduced before it reaches the desired position. Due to size limitations, the isolation ball passes through the activation ball seat and falls into the isolation ball seat, where it is slowly pressed. The pressure is controlled to prevent the indexing sleeve from moving downwards again.

2. The downhole drilling circulation bypass tool according to claim 1, characterized in that... The central tube at the position between the indexing sleeve and the lower guide sleeve has waist-shaped holes that are evenly distributed around its circumference.

3. The downhole drilling circulation bypass tool according to claim 1 or 2, characterized in that... Both the upper and lower guide sleeves are fixedly installed together with the body by pins. An O-ring is provided between the pin and the body. A support platform is provided on the inner side of the body corresponding to the lower end of the lower guide sleeve. The lower end of the lower guide sleeve is located on the upper side of the support platform. An O-ring is provided between the activation ball seat and the central tube. A sealing ring is provided between the isolation ball seat and the central tube. An O-ring is provided between the central tube corresponding to the activation ball seat and the body. At least one U-shaped sealing ring is provided between the body and the indexing sleeve at intervals above and below the external circulation hole.

4. A method for unlimited circulation bypass using the downhole circulating bypass tool as described in claim 3, characterized in that... This includes high-volume well-washing methods and leak-sealing methods: High-volume well washing method: (1) Activation ball is put into the wellhead. The degradation time of the activation ball must be greater than the time of pumping to the ball seat; (2) Pump the activation ball, reduce the pumping flow rate and slowly press it before pumping it into place; (3) The activation ball pushes the central tube and the indexing sleeve downwards. The guide surface of the guide key in the indexing sleeve contacts the guide surface of the lower guide key in the lower guide sleeve. The hydraulic pressure pushes the indexing sleeve to rotate downwards to the bottom. At this time, the circulation hole in the indexing sleeve and the outer circulation hole on the body are axially misaligned and circumferentially misaligned. (4) Continue to pressurize to 20MPa. The activation ball forces the activation ball seat to undergo plastic deformation. The hydraulic pressure knocks the activation ball off. The activation ball passes through the activation ball seat and the isolation ball seat continuously and falls into the lower drill bit, waiting for degradation. (5) The cylindrical spiral compression spring pushes the central tube and the indexing sleeve to rotate upward. The guide surface of the guide key on the indexing sleeve contacts the guide surface of the guide key at the top of the upper guide sleeve. The cylindrical spiral compression spring pushes the indexing sleeve to rotate 18°. The guide key on the indexing sleeve enters the short groove of the upper guide sleeve. The circulation hole in the indexing sleeve is aligned with the external circulation hole on the body, and the bypass flow channel is opened. (6) At this time, the drilling fluid in the drill string circulates through the bypass channel and the drill bit water hole to carry out a large-volume well washing operation. The flow channel ratio design allows the flow rate ratio of the bypass channel and the drill bit water hole to be 3:1 to 4:

1. (7) After the large-volume well washing operation is completed, an activation ball is put into the wellhead. The degradation time of the activation ball must be longer than the time it takes to pump to the ball seat. (8) Pump the activation ball, reduce the pumping flow rate and slowly press it before pumping it into place; (9) The activation ball pushes the central tube and the indexing sleeve downwards. The guide surface of the guide key in the indexing sleeve contacts the guide surface of the lower guide key in the lower guide sleeve. The hydraulic pressure pushes the indexing sleeve to rotate and descend to the bottom. At this time, the circulation hole in the indexing sleeve and the outer circulation hole on the body are axially misaligned and circumferentially misaligned again. (10) Continue to pressurize to 20MPa. The activation ball forces the activation ball seat to undergo plastic deformation. The hydraulic pressure knocks the activation ball off. The activation ball passes through the activation ball seat and the isolation ball seat continuously and falls into the lower drill bit, waiting for degradation. (11) The cylindrical spiral compression spring pushes the central tube and the indexing sleeve to move upward. The guide surface of the guide key on the indexing sleeve contacts the guide surface of the guide key at the top of the upper guide sleeve. The cylindrical spiral compression spring pushes the indexing sleeve to rotate 18°. The guide key of the indexing sleeve enters the long groove of the upper guide sleeve, and the tool returns to its initial state. Leak sealing methods: (1) Activation balls are put into the wellhead, and the degradation time of the activation balls must be greater than the time it takes to pump them to the ball seat; (2) Pump the activation ball, reduce the pumping flow rate and slowly press it before pumping it into place; (3) The activation ball pushes the central tube and the indexing sleeve downwards. The guide surface of the guide key in the indexing sleeve contacts the guide surface of the lower guide key in the lower guide sleeve. The hydraulic pressure pushes the indexing sleeve to rotate downwards to the bottom. At this time, the circulation hole in the indexing sleeve and the outer circulation hole on the body are axially misaligned and circumferentially misaligned. (4) Continue to pressurize to 20MPa. The activation ball forces the activation ball seat to undergo plastic deformation. The hydraulic pressure knocks the activation ball off. The activation ball passes through the activation ball seat and the isolation ball seat continuously and falls into the lower drill bit, waiting for degradation. (5) The cylindrical spiral compression spring pushes the central tube and the indexing sleeve to move upward. The guide surface of the indexing sleeve guide key contacts the guide surface of the upper guide sleeve guide key. The cylindrical spiral compression spring pushes the indexing sleeve to rotate 18°. The indexing sleeve guide key enters the short groove of the upper guide sleeve. The circulation hole in the indexing sleeve is aligned with the external circulation hole on the body, and the bypass flow channel is opened. (6) Insert isolation balls into the wellhead. The degradation time of the isolation balls must be longer than the estimated time for plugging operations. (7) Pump the isolation ball. Before pumping it into place, reduce the pumping flow rate. Due to size limitations, the isolation ball passes through the activation ball seat and falls into the isolation ball seat. Slowly press it and control the pressure so as not to push the indexing sleeve downward again. (8) Perform plugging operation. If the plugging operation takes longer than the estimated time, drop the isolation ball again from the wellhead. After the first isolation ball degrades, it will fall back into the ball seat to isolate the drilling fluid. (9) After the plugging operation is completed, an activation ball is put into the wellhead. The degradation time of the activation ball must be longer than the time it takes to be pumped to the ball seat. (10) Pump the activation ball, reduce the pumping flow rate and slowly press it before pumping it into place; (11) The activation ball pushes the central tube and the indexing sleeve downwards. The guide surface of the guide key in the indexing sleeve contacts the guide surface of the guide key in the lower guide sleeve. The hydraulic pressure pushes the indexing sleeve to rotate downwards to the bottom. At this time, the circulation hole in the indexing sleeve and the outer circulation hole on the body are axially misaligned and circumferentially misaligned again. (12) Continue to pressurize to 20MPa. The activation ball forces the activation ball seat to undergo plastic deformation. The hydraulic pressure knocks the activation ball and the isolation ball off. The activation ball passes through the activation ball seat and the isolation ball seat continuously and falls into the lower drill bit, waiting for degradation. (13) The cylindrical spiral compression spring pushes the central tube and the indexing sleeve to move upward. The guide surface of the guide key on the indexing sleeve contacts the guide surface of the guide key at the top of the upper guide sleeve. The cylindrical spiral compression spring pushes the indexing sleeve to rotate 18°. The guide key on the indexing sleeve enters the long groove of the upper guide sleeve, and the tool returns to its initial state.

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