Downhole while-drilling circulation bypass tool and infinite circulation bypass method

Abstract

The invention relates to the technical field of circulating bypass tools, in particular to an underground while-drilling circulating bypass tool and an infinite circulating bypass method. The underground while-drilling circulating bypass tool comprises a body, an upper guide sleeve, a lower guide sleeve, a central pipe, a transposition sliding sleeve, an activation ball seat and an isolation ball seat; an upper guide sleeve and a lower guide sleeve which can be matched with the transposition sliding sleeve to steer are arranged on the upper side and the lower side of the transposition sliding sleeve respectively, the upper guide sleeve and the lower guide sleeve are installed together with the corresponding positions of the body respectively, a center pipe is installed in the transposition sliding sleeve, and the lower end of the center pipe is located below the lower guide sleeve. The tool is reasonable and compact in structure and convenient to use, the upper guide sleeve, the transposition sliding sleeve and the lower guide sleeve are combined, periodic alignment and dislocation of the circulation holes are controlled to achieve conversion between different working states of the tool, no ball basket is arranged on the lower portion, the effective length connected into a drill column can be shortened, and convenience is brought to bottom drilling tool combination design, wellhead installation and transportation.

Description

Technical Field

[0001] The invention relates to the technical field of circulation bypass tools, in particular to an underground circulation bypass tool while drilling and an infinite circulation bypass method. Background Art

[0002] The circulating bypass tool is a ground-controlled, leak-proof and large-volume well-washing bypass tool that can realize multiple forward and lateral (bypass) alternating cycles. According to the number of activations of the tool, it can be divided into limited-time tools and unlimited-time tools. The number of activations of limited-time activation tools is limited by the length of the ball basket, and their use in complex working conditions is often restricted. After the functional ball of the limited-time activation tool completes the mechanical action, it falls into the lower ball basket, affecting the internal passability of the tool. With the continuous deepening of the development of deep wells, ultra-deep wells, and complex process wells, the leak-proof and large-volume well-washing processes have put forward requirements for more activation times, simpler operation, and higher stability for the circulating bypass tool. Summary of the invention

[0003] The present invention provides a downhole circulating bypass tool while drilling and an infinite circulating bypass method, which overcomes the deficiencies of the above-mentioned prior art and can effectively solve the problem that the functional ball of the existing circulating bypass tool falls into the lower ball basket after completing the mechanical action, affecting the internal passability 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 main body, an upper guide sleeve, a lower guide sleeve, a center pipe, a transfer sleeve, an activation ball seat and an isolation ball seat, a transfer sleeve is arranged in the main body, and an upper guide sleeve and a lower guide sleeve that can cooperate with the transfer sleeve for steering are respectively arranged on the upper and lower sides of the transfer sleeve, the upper guide sleeve and the lower guide sleeve are respectively installed together with the corresponding positions of the main body, a center pipe is installed in the transfer sleeve, and the lower end of the center pipe is located below the lower guide sleeve, a mounting platform is provided on the inner side of the lower part of the main body, a cylindrical helical compression spring is provided between the lower end of the center pipe and the mounting platform, an activation ball seat and an isolation ball seat are respectively installed in the center pipe corresponding to the upper and lower positions of the transfer sleeve, an inner circulation hole and a middle circulation hole that are connected are respectively provided on the center pipe and the transfer sleeve corresponding to the position between the activation ball seat and the isolation ball seat, and an outer circulation hole that passes through inside and outside is provided on the main body corresponding to the position below the middle circulation hole.

[0005] The following are further optimizations and / or improvements to the above technical solutions: The lower end of the above-mentioned upper guide sleeve may be evenly distributed with ten top guide keys along the circumference, five long grooves and five short grooves are formed between adjacent top guide keys, and the long grooves and short grooves are alternately arranged; the upper end of the indexing sleeve is evenly distributed with five upper guide keys along the circumference, and the upper guide keys are located in the long grooves; the lower end of the indexing sleeve is evenly distributed with ten middle guide keys along the circumference, and middle key grooves are formed between the middle guide keys; the upper end of the lower guide sleeve is evenly distributed with ten lower guide keys along the circumference, and lower key grooves are formed between the lower guide keys; the middle guide keys can cooperate with the lower key grooves, and the middle key grooves can cooperate 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.

[0006] The central tube at the position corresponding to the indexing sleeve and the lower guide sleeve may be evenly distributed along the circumference with waist-shaped holes penetrating inside and outside.

[0007] The activation balls and isolation balls mentioned above can be made of degradable aluminum-magnesium alloy.

[0008] The above-mentioned upper guide sleeve and lower guide sleeve can be fixedly installed together with the main body by pins, an O-ring is provided between the pin and the main body, a support platform is provided on the inner side of the main body corresponding to the lower end position 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 center tube, a sealing ring is provided between the isolation ball seat and the center tube, an O-ring is provided between the center tube and the main body corresponding to the position of the activation ball seat, and at least one U-ring is provided between the main body and the transfer sleeve at upper and lower intervals corresponding to the positions above and below the external circulation hole.

[0009] The second technical solution of the present invention is achieved by the following measures: an infinite circulation bypass method includes a large displacement well washing method and a plugging method: Large-volume well washing method: (1) Put an activation ball 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; (2) Pump the activation ball, reduce the pumping volume before pumping into place, and slowly pressurize; (3) The activation ball pushes the center tube and the indexing sleeve downward, and the guide surface of the guide key in the indexing sleeve contacts the guide surface of the lower guide key of the lower guide sleeve. The hydraulic pressure pushes the indexing sleeve to rotate downward 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 hold the pressure to 20 MPa. The activation ball forces the activation ball seat to undergo plastic deformation. The hydraulic pressure knocks the activation ball down. The activation ball passes through the activation ball seat and the isolation ball seat continuously and falls into the lower drilling tool, waiting to be degraded. (5) The cylindrical helical compression spring pushes the center 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 helical 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 can circulate through the bypass flow channel and the drill bit water hole to perform a large-volume well washing operation. The flow channel ratio design allows the ratio of the bypass and drill bit water hole flow channels 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 greater than the time it takes to be pumped to the ball seat; (8) Pump the activation ball, reduce the pumping volume before pumping into place, and slowly pressurize; (9) The activation ball pushes the center tube and the indexing sleeve downward, and the guide surface of the guide key in the indexing sleeve contacts the guide surface of the lower guide key of the lower guide sleeve. The hydraulic pressure pushes the indexing sleeve to rotate downward 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 hold the pressure to 20 MPa. The activation ball forces the activation ball seat to undergo plastic deformation. The hydraulic pressure knocks the activation ball down. The activation ball passes through the activation ball seat and the isolation ball seat continuously and falls into the lower drilling tool, waiting to be degraded. (11) The cylindrical helical compression spring pushes the center tube and the indexing sleeve upward, and 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 helical compression spring pushes the indexing sleeve to rotate 18°, and the guide key of the indexing sleeve enters the long groove of the upper guide sleeve, and the tool returns to its initial state. Leakage plugging method: (1) The activation ball is put into the wellhead, and the degradation time of the activation ball must be greater than the time it takes to be pumped to the ball seat; (2) Pump the activation ball, reduce the pumping volume before pumping into place, and slowly pressurize; (3) The activation ball pushes the center tube and the indexing sleeve downward, and the guide surface of the guide key in the indexing sleeve contacts the guide surface of the lower guide key of the lower guide sleeve. The hydraulic pressure pushes the indexing sleeve to rotate downward 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 hold the pressure to 20 MPa. The activation ball forces the activation ball seat to undergo plastic deformation. The hydraulic pressure knocks the activation ball down. The activation ball passes through the activation ball seat and the isolation ball seat continuously and falls into the lower drilling tool, waiting to be degraded. (5) The cylindrical helical compression spring pushes the center tube and the indexing sleeve upward, and the guide surface of the indexing sleeve guide key contacts the guide surface of the upper guide sleeve guide key. The cylindrical helical compression spring pushes the indexing sleeve to rotate 18°, and 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) Isolation balls are placed at the wellhead, and the degradation time of the isolation balls must be longer than the estimated plugging operation time; (7) Pump the isolation ball. Reduce the pumping displacement before pumping it into place. Due to size limitations, the isolation ball passes through the activation ball seat and falls into the isolation ball seat. Slowly press it. Control the pressure so that the indexing sleeve does not move downward again. (8) Perform plugging operations. If the plugging operation takes longer than the estimated time, drop an isolation ball from the wellhead again. After the first isolation ball degrades, it will fall into the ball seat again 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 greater than the time it takes to be pumped to the ball seat; (10) Pump the activation ball, reduce the pumping volume before pumping into place, and slowly pressurize; (11) The activation ball pushes the center tube and the indexing sleeve downward, and the guide surface of the guide key in the indexing sleeve contacts the guide surface of the lower guide key of the lower guide sleeve. The hydraulic pressure pushes the indexing sleeve to rotate downward 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 hold the pressure to 20 MPa. The activation ball forces the activation ball seat to undergo plastic deformation. The hydraulic pressure knocks down the activation ball and the isolation ball. The activation ball passes through the activation ball seat and the isolation ball seat continuously and falls into the lower drilling tool, waiting to be degraded. (13) The cylindrical helical compression spring pushes the center tube and the transfer sleeve upward, and the guide surface of the guide key on the transfer sleeve contacts the guide surface of the guide key at the top of the upper guide sleeve. The cylindrical helical compression spring pushes the transfer sleeve to rotate 18°, and the guide key on the transfer sleeve enters the long groove of the upper guide sleeve, and the tool returns to its initial state.

[0010] The present invention has a reasonable and compact structure and is easy to use. It adopts an upper guide sleeve, a transfer sleeve, and a lower guide sleeve combination to control the periodic alignment and dislocation of the circulation holes 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, bringing convenience to the bottom drilling tool assembly design, wellhead installation, and transportation. BRIEF DESCRIPTION OF THE DRAWINGS

[0011] Attached Figure 1 It is a schematic diagram of the front cross-sectional structure of an embodiment of the present invention.

[0012] Attached Figure 2 For attachment Figure 1 Schematic diagram of the enlarged cross-sectional structure of the upper guide sleeve and the transfer sleeve.

[0013] The codes in the accompanying drawings are: 1 is the main body, 2 is the upper guide sleeve, 3 is the lower guide sleeve, 4 is the center tube, 5 is the transfer 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 table, 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 waist-shaped hole, 21 is the pin, 22 is the O-ring, 23 is the U-shaped sealing ring, and 24 is the lower guide key. DETAILED DESCRIPTION

[0014] The present invention is not limited by the following embodiments, and specific implementation methods can be determined based on the technical solution of the present invention and actual conditions.

[0015] In the present invention, for the convenience of description, the relative position relationship of each component is described according to the attached Figure 1 The positional relationships such as front, back, top, bottom, left, and right are described according to the layout directions of the drawings in the specification.

[0016] The present invention will be further described below in conjunction with embodiments and drawings: Embodiment 1: As attached Figure 1 , 2 As shown, the downhole circulating bypass tool while drilling includes a body 1, an upper guide sleeve 2, a lower guide sleeve 3, a center pipe 4, a transfer sleeve 5, an activation ball seat 7 and an isolation ball seat 9. The transfer sleeve 5 is arranged in the body 1, and the upper and lower sides of the transfer sleeve 5 are respectively provided with an upper guide sleeve 2 and a lower guide sleeve 3 that can cooperate with the transfer sleeve 5 for turning. The upper guide sleeve 2 and the lower guide sleeve 3 are respectively installed at corresponding positions of the body 1, and the transfer sleeve 5 is installed with a center pipe 4, and the lower end of the center pipe 4 is located below the lower guide sleeve 3. A mounting platform 10 is provided on the inner side of the lower part of the main body 1, and 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 corresponding to the upper and lower positions of the transfer sleeve 5. A connected inner circulation hole 12 and a middle circulation hole 13 are respectively provided on the central tube 4 and the transfer sleeve 5 corresponding to the position between the activation ball seat 7 and the isolation ball seat 9. An outer circulation hole 14 that penetrates inside and outside is provided on the main body 1 corresponding to the position below the middle circulation hole 13.

[0017] The body 1, the indexing sleeve 5, and the center tube 4 are evenly distributed with 5 circulation holes of the same size. In the initial state, the circulation hole 13 in the indexing sleeve 5 and the inner circulation hole 12 in the center tube 4 are located axially directly above the outer circulation hole 14 of the body 1. The indexing sleeve 5 can periodically perform axial reciprocating motion and circumferential rotation under the index of the guide key guide surface 19 of the upper guide sleeve 2 and the lower guide sleeve 3, so that the circulation hole 13 in the indexing sleeve 5 and the inner circulation hole 12 in the center tube 4 are periodically aligned and misaligned with the outer circulation hole 14 of the body 1.

[0018] The present invention adopts an upper guide sleeve 2, a transfer sleeve 5, and a lower guide sleeve 3 combination to control the periodic alignment and misalignment of the circulation holes to realize the conversion between different working states of the tool. The upper guide sleeve 2, the transfer 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. The present invention has no ball basket at the bottom, which can shorten the effective length of the drill string, bringing convenience to the bottom drilling tool assembly design, wellhead installation, and transportation.

[0019] Different sized balls and ball seats can be used to connect multiple tools in the drill string to achieve selective activation and deactivation of the tools The above-mentioned downhole circulation bypass tool can be further optimized and / or improved according to actual needs: Embodiment 2: As attached Figure 1 , 2 As shown, ten top guide keys are evenly distributed along the circumference at 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, and the long grooves 15 and the short grooves 16 are alternately arranged. Five upper guide keys 18 are evenly distributed along the circumference at the upper end of the transfer sleeve 5, and the upper guide key 18 is located in the long groove 15. Ten middle guide keys 17 are evenly distributed along the circumference at the lower end of the transfer sleeve 5, and middle key grooves are formed between the middle guide keys 17. Ten lower guide keys 24 are evenly distributed along the circumference at the upper end of the lower guide sleeve 3, and 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.

[0020] In the initial state, the upper guide key 18 is located in the long groove 15 , and the middle guide key 17 is located above the lower guide key 24 .

[0021] Embodiment 3: As attached Figure 1 As shown, the center tube 4 corresponding to the position between the indexing sleeve 5 and the lower guide sleeve 3 is evenly distributed with waist-shaped holes 20 that penetrate inside and outside along the circumference. The center tube 4 is evenly distributed with waist-shaped holes 20 flow channels to avoid the formation of hydraulic dead space between the indexing sleeve 5 and the lower guide sleeve 3 during the downward process.

[0022] Embodiment 4: As attached Figure 1 As shown, the activation ball 6 and the isolation ball 8 are made of a degradable aluminum-magnesium alloy. The degradable material will not block the passage in the body 1, and the tool can be activated and closed an unlimited number of times.

[0023] Embodiment 5: As attached Figure 1As shown, the upper guide sleeve 2 and the lower guide sleeve 3 are fixedly installed with the body 1 through the pin 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, and 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 center pipe 4, a sealing ring is provided between the isolation ball seat 9 and the center pipe 4, an O-ring 22 is provided between the center pipe 4 and the body 1 corresponding to the position of the activation ball seat 7, and at least one U-ring 23 is provided between the body 1 and the transfer sleeve 5 at the upper and lower positions corresponding to the outer circulation hole 14. Sealing is performed by sealing rings to prevent drilling fluid from affecting the movement of components.

[0024] Embodiment 6: As attached Figure 1 , 2 As shown, the infinite cycle bypass method includes a large-volume well washing method and a plugging method: Large-volume well washing method: (1) Activation ball 6 is put into the wellhead. The degradation time of activation ball 6 must be longer than the time it takes to be pumped to the ball seat; (2) Pumping activation ball 6, reduce the pumping displacement before pumping into place, and slowly pressurize; (3) The activation ball 6 pushes the center tube 4 and the indexing sleeve 5 downward, and the guide surface 19 of the guide key 17 in the indexing sleeve 5 contacts the guide surface 19 of the lower guide key 24 of the lower guide sleeve 3. The hydraulic pressure pushes the indexing sleeve 5 to rotate downward to the bottom. At this time, the circulation hole 13 in the indexing sleeve 5 and the outer circulation hole 14 on the body 1 are axially misaligned and circumferentially misaligned; (4) Continue to hold the pressure to 20 MPa, the activation ball 6 forces the activation ball seat 7 to undergo plastic deformation, and the hydraulic pressure knocks the activation ball 6 down. The activation ball 6 passes through the activation ball seat 7 and the isolation ball seat 9 continuously and falls into the lower drilling tool, waiting to be degraded; (5) The cylindrical helical compression spring 11 pushes the center tube 4 and the indexing sleeve 5 to rotate upward, and the guide surface 19 of the guide key 18 on the indexing sleeve 5 contacts the guide surface 19 of the top guide key of the upper guide sleeve 2. The cylindrical helical compression spring 11 pushes the indexing sleeve 5 to rotate 18°, and 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 outer circulation hole 14 on the body 1, and the bypass flow channel is opened; (6) At this time, the drilling fluid in the drill string can circulate through the bypass flow channel and the drill bit water hole to perform a large-volume well washing operation. The flow channel ratio design allows the ratio of the bypass and drill bit water hole flow channels to be 3:1 to 4:1; (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; (8) Pumping activation ball 6, reduce the pumping displacement before pumping into place, and slowly pressurize; (9) The activation ball 6 pushes the center tube 4 and the indexing sleeve 5 downward, and the guide surface 19 of the guide key 17 in the indexing sleeve 5 contacts the guide surface 19 of the lower guide key 24 of the lower guide sleeve 3, and the hydraulic pressure pushes the indexing sleeve 5 to rotate downward to the bottom. At this time, the circulation hole 13 in the indexing sleeve 5 and the outer circulation hole 14 on the body 1 are axially misaligned and circumferentially misaligned again; (10) Continue to hold the pressure to 20 MPa, the activation ball 6 forces the activation ball seat 7 to undergo plastic deformation, and the hydraulic pressure knocks the activation ball 6 down. The activation ball 6 passes through the activation ball seat 7 and the isolation ball seat 9 continuously and falls into the lower drilling tool, waiting to be degraded; (11) The cylindrical helical compression spring 11 pushes the center tube 4 and the indexing sleeve 5 upward, and 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 helical compression spring 11 pushes the indexing sleeve 5 to rotate 18°, and 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. Leakage plugging method: (1) The activation ball 6 is put into the wellhead. The degradation time of the activation ball 6 must be longer than the time it takes to be pumped to the ball seat; (2) Pumping activation ball 6, reduce the pumping displacement before pumping into place, and slowly pressurize; (3) The activation ball 6 pushes the center tube 4 and the indexing sleeve 5 downward, and the guide surface 19 of the guide key 17 in the indexing sleeve 5 contacts the guide surface 19 of the lower guide key 24 of the lower guide sleeve 3. The hydraulic pressure pushes the indexing sleeve 5 to rotate downward to the bottom. At this time, the circulation hole 13 in the indexing sleeve 5 and the outer circulation hole 14 on the body 1 are axially misaligned and circumferentially misaligned; (4) Continue to hold the pressure to 20 MPa, the activation ball 6 forces the activation ball seat 7 to undergo plastic deformation, and the hydraulic pressure knocks the activation ball 6 down. The activation ball 6 passes through the activation ball seat 7 and the isolation ball seat 9 continuously and falls into the lower drilling tool, waiting to be degraded; (5) The cylindrical helical compression spring 11 pushes the center tube 4 and the indexing sleeve 5 upward, and the guide key guide surface 19 of the indexing sleeve 5 contacts the guide key guide surface 19 of the upper guide sleeve 2. The cylindrical helical compression spring 11 pushes the indexing sleeve 5 to rotate 18°, and 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 outer circulation hole 14 on the body 1, and the bypass flow channel is opened; (6) Isolation balls 8 are placed at the wellhead, and the degradation time of the isolation balls 8 must be longer than the estimated plugging operation time; (7) Pump the isolation ball 8 and reduce the pumping displacement before pumping it into place. Due to size limitations, the isolation ball 8 passes through the activation ball seat 7 and falls into the isolation ball seat 9, slowly pressing against it. The control pressure must not push the indexing sleeve 5 downward again; (8) Perform plugging operations. If the plugging operation takes longer than the estimated time, the isolation ball 8 is dropped from the wellhead again. After the first isolation ball 8 is degraded, it falls into the ball seat again to isolate the drilling fluid; (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; (10) Pumping activation ball 6, reduce the pumping displacement before pumping into place, and slowly pressurize; (11) The activation ball 6 pushes the center tube 4 and the indexing sleeve 5 downward, and the guide surface 19 of the guide key 17 in the indexing sleeve 5 contacts the guide surface 19 of the lower guide key 24 of the lower guide sleeve 3, and the hydraulic pressure pushes the indexing sleeve 5 to rotate downward to the bottom. At this time, the circulation hole 13 in the indexing sleeve 5 and the outer circulation hole 14 on the body 1 are axially misaligned and circumferentially misaligned again; (12) Continue to hold the pressure to 20 MPa, 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, and the activation ball 6 passes through the activation ball seat 7 and the isolation ball seat 9 continuously, and falls into the lower drilling tool, waiting to be degraded; (13) The cylindrical helical compression spring 11 pushes the center tube 4 and the transfer sleeve 5 upward, and the guide surface 19 of the guide key 18 on the transfer sleeve 5 contacts the guide surface 19 of the top guide key of the upper guide sleeve 2. The cylindrical helical compression spring 11 pushes the transfer sleeve 5 to rotate 18°, and the guide key 18 on the transfer sleeve 5 enters the long groove 15 of the upper guide sleeve 2, and the tool returns to its initial state.

[0025] The above technical features constitute the embodiments of the present invention, which have strong adaptability and implementation effect. Non-essential technical features can be added or reduced according to actual needs to meet the requirements of different situations.

Claims

1. A downhole circulation bypass tool, characterized in that It includes a main body, an upper guide sleeve, a lower guide sleeve, a center tube, a transfer sleeve, an activation ball seat and an isolation ball seat. A transfer sleeve is arranged in the main body. An upper guide sleeve and a lower guide sleeve are respectively arranged on the upper and lower sides of the transfer sleeve to cooperate with the transfer sleeve for steering. The upper guide sleeve and the lower guide sleeve are respectively installed with the corresponding positions of the main body. A center tube is installed in the transfer sleeve. The lower end of the center tube is located below the lower guide sleeve. A mounting platform is provided on the inner side of the lower part of the main body. A cylindrical helical compression spring is provided between the lower end of the center tube and the mounting platform. An activation ball seat and an isolation ball seat are respectively installed in the center tube corresponding to the upper and lower positions of the transfer sleeve. A connected inner circulation hole and a middle circulation hole are respectively provided on the center tube and the transfer sleeve corresponding to the position between the activation ball seat and the isolation ball seat. An outer circulation hole that penetrates inside and outside is provided on the main body corresponding to the position below the middle circulation hole.

2. The downhole circulation bypass tool according to claim 1, characterized in that The lower end of the upper guide sleeve is evenly distributed with ten top guide keys along the circumference, and five long grooves and five short grooves are formed between adjacent top guide keys, and the long grooves and short grooves are alternately arranged. The upper end of the indexing sleeve is evenly distributed with five upper guide keys along the circumference, and the upper guide keys are located in the long grooves. The lower end of the indexing sleeve is evenly distributed with ten middle guide keys along the circumference, and middle key grooves are formed between the middle guide keys. The upper end of the lower guide sleeve is evenly distributed with ten lower guide keys along the circumference, and lower key grooves are formed between the lower guide keys. The middle guide keys can cooperate with the lower key grooves, and the middle key grooves can cooperate 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.

3. The downhole circulation bypass tool according to claim 1 or 2, characterized in that The center tube corresponding to the position between the indexing sliding sleeve and the lower guide sleeve is evenly distributed along the circumference with waist-shaped holes penetrating inside and outside.

4. The downhole circulation bypass tool according to claim 1 or 2, characterized in that The activation ball and isolation ball are made of degradable aluminum-magnesium alloy.

5. The downhole circulation bypass tool according to claim 3, characterized in that The activation ball and isolation ball are made of degradable aluminum-magnesium alloy.

6. The downhole circulation bypass tool according to claim 1, 2 or 5, characterized in that The upper guide sleeve and the lower guide sleeve are fixed together with the main body by pins, an O-ring is provided between the pin and the main body, a support platform is provided on the inner side of the main body corresponding to the lower end position 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 center tube, a sealing ring is provided between the isolation ball seat and the center tube, an O-ring is provided between the center tube and the main body corresponding to the position of the activation ball seat, and at least one U-ring is provided between the main body and the transfer sleeve at upper and lower intervals corresponding to the positions above and below the external circulation hole.

7. The downhole circulation bypass tool according to claim 3, characterized in that The upper guide sleeve and the lower guide sleeve are fixed together with the main body by pins, and O-rings are provided between the pins and the main body. A support platform is provided on the inner side of the main body corresponding to the lower end position of the lower guide sleeve, and 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 center tube, an O-ring is provided between the isolation ball seat and the center tube, an O-ring is provided between the center tube and the main body corresponding to the position of the activation ball seat, and at least one U-shaped sealing ring is provided between the main body and the transfer sleeve at upper and lower intervals corresponding to the positions above and below the external circulation hole.

8. The downhole circulation bypass tool according to claim 4, characterized in that The upper guide sleeve and the lower guide sleeve are fixed together with the main body by pins, and O-rings are provided between the pins and the main body. A support platform is provided on the inner side of the main body corresponding to the lower end position of the lower guide sleeve, and 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 center tube, an O-ring is provided between the isolation ball seat and the center tube, an O-ring is provided between the center tube and the main body corresponding to the position of the activation ball seat, and at least one U-shaped sealing ring is provided between the main body and the transfer sleeve at upper and lower intervals corresponding to the positions above and below the external circulation hole.

9. An infinite circulation bypass method using the downhole circulation bypass tool as claimed in any one of claims 4 to 8, characterized in that Including large-volume well washing methods and plugging methods: Large-volume well washing method: (1) Put an activation ball 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; (2) Pump the activation ball, reduce the pumping volume before pumping into place, and slowly pressurize; (3) The activation ball pushes the center tube and the indexing sleeve downward, and the guide surface of the guide key in the indexing sleeve contacts the guide surface of the lower guide key of the lower guide sleeve. The hydraulic pressure pushes the indexing sleeve to rotate downward 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 hold the pressure to 20 MPa. The activation ball forces the activation ball seat to undergo plastic deformation. The hydraulic pressure knocks the activation ball down. The activation ball passes through the activation ball seat and the isolation ball seat continuously and falls into the lower drilling tool, waiting to be degraded. (5) The cylindrical helical compression spring pushes the center 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 helical 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 can circulate through the bypass flow channel and the drill bit water hole to perform a large-volume well washing operation. The flow channel ratio design allows the ratio of the bypass and drill bit water hole flow channels 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 greater than the time it takes to be pumped to the ball seat; (8) Pump the activation ball, reduce the pumping volume before pumping into place, and slowly pressurize; (9) The activation ball pushes the center tube and the indexing sleeve downward, and the guide surface of the guide key in the indexing sleeve contacts the guide surface of the lower guide key of the lower guide sleeve. The hydraulic pressure pushes the indexing sleeve to rotate downward 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 hold the pressure to 20 MPa. The activation ball forces the activation ball seat to undergo plastic deformation. The hydraulic pressure knocks the activation ball down. The activation ball passes through the activation ball seat and the isolation ball seat continuously and falls into the lower drilling tool, waiting to be degraded. (11) The cylindrical helical compression spring pushes the center tube and the indexing sleeve upward, and 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 helical compression spring pushes the indexing sleeve to rotate 18°, and the guide key of the indexing sleeve enters the long groove of the upper guide sleeve, and the tool returns to its initial state. Leakage plugging method: (1) The activation ball is put into the wellhead, and the degradation time of the activation ball must be longer than the time it takes to be pumped to the ball seat; (2) Pump the activation ball, reduce the pumping volume before pumping into place, and slowly pressurize; (3) The activation ball pushes the center tube and the indexing sleeve downward, and the guide surface of the guide key in the indexing sleeve contacts the guide surface of the lower guide key of the lower guide sleeve. The hydraulic pressure pushes the indexing sleeve to rotate downward 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 hold the pressure to 20 MPa. The activation ball forces the activation ball seat to undergo plastic deformation. The hydraulic pressure knocks the activation ball down. The activation ball passes through the activation ball seat and the isolation ball seat continuously and falls into the lower drilling tool, waiting to be degraded. (5) The cylindrical helical compression spring pushes the center tube and the indexing sleeve upward, and the guide surface of the indexing sleeve guide key contacts the guide surface of the upper guide sleeve guide key. The cylindrical helical compression spring pushes the indexing sleeve to rotate 18°, and 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) Isolation balls are placed at the wellhead, and the degradation time of the isolation balls must be longer than the estimated plugging operation time; (7) Pump the isolation ball. Reduce the pumping displacement before pumping it into place. Due to size limitations, the isolation ball passes through the activation ball seat and falls into the isolation ball seat. Slowly press it. Control the pressure so that the indexing sleeve does not move downward again. (8) Perform plugging operations. If the plugging operation takes longer than the estimated time, drop an isolation ball from the wellhead again. After the first isolation ball degrades, it will fall into the ball seat again 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 greater than the time it takes to be pumped to the ball seat; (10) Pump the activation ball, reduce the pumping volume before pumping into place, and slowly pressurize; (11) The activation ball pushes the center tube and the indexing sleeve downward, and the guide surface of the guide key in the indexing sleeve contacts the guide surface of the lower guide key of the lower guide sleeve. The hydraulic pressure pushes the indexing sleeve to rotate downward 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 hold the pressure to 20 MPa. The activation ball forces the activation ball seat to undergo plastic deformation. The hydraulic pressure knocks down the activation ball and the isolation ball. The activation ball passes through the activation ball seat and the isolation ball seat continuously and falls into the lower drilling tool, waiting to be degraded. (13) The cylindrical helical compression spring pushes the center tube and the transfer sleeve upward, and the guide surface of the guide key on the transfer sleeve contacts the guide surface of the guide key at the top of the upper guide sleeve. The cylindrical helical compression spring pushes the transfer sleeve to rotate 18°, and the guide key on the transfer sleeve enters the long groove of the upper guide sleeve, and the tool returns to its initial state.

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