Multifunctional integrated multilateral well service tool

Abstract

The invention belongs to the field of petroleum and natural gas resource development, particularly relates to a multifunctional integrated multilateral well service tool, and aims to solve the problems of complex operation and low timeliness of the whole process. The tubular column comprises an inner tubular column body and an outer tubular column body which are connected together. The inner tubular column comprises an upper joint, a runner sleeve, a drawing sleeve, an upper connecting sleeve, a lower connecting sleeve, a rotating shaft sleeve, a tubular column reducing sleeve, an inner central tube, a pressure isolation sleeve, a sealing insertion tube, an extension tube and a central tube ball seat; the outer tubular column is used for being connected with the outer tubular column function module. Modular and universal design is adopted, connectors can be reserved for connecting well completion tools such as hangers and packers of different types and different purposes, feeding, setting and hydraulic back-off double-releasing functions are provided for the tools, the universality of the tools is improved, the modular and universal design is achieved, meanwhile, the structural optimization design is adopted, and the construction cost is reduced. The service tool assembly is integrated with a press-down rotating jam releasing function and a circulating jam releasing function, so that the tool tripping-in reliability is enhanced.

Description

A multi-functional integrated branch well service tool Technical Field

[0001] This invention belongs to the technical field of oil and gas resource development, and specifically relates to a multi-functional integrated branch well service tool, which provides running, setting, and release services for tools such as open-hole anchors, open-hole packers, tailpipe hangers, and top packers; provides running and slurry replacement services for screen completion strings and bottom gravel packing strings; and provides positioning and orientation services for other branch well tools such as directional drills and radial drills. Background Technology

[0002] In current TAML 3-4 level branch well completion technology, the integration of tools such as open-hole anchors, open-hole packers, tailpipe hangers, and top packers is low. The lower branch completion string is run separately, and a support tool at the branch well interface needs to be connected in series on the completion string. After the upper branch is drilled, a separate tool needs to be run to open the blind plate in the support tool to establish a connection between the upper and lower branches. The entire process requires 3-4 drilling runs to complete, which is complicated, inefficient, and costly. Furthermore, each branch well tool is used separately to achieve a specific function, lacking a modular design, resulting in poor tool versatility and universality, which hinders the promotion of branch well technology. Summary of the Invention

[0003] To address the aforementioned problems in existing technologies, namely the complexity and low timeliness of the entire process, this invention provides a multifunctional integrated branch well service tool. It adopts a modular and universal design, providing interfaces to connect to various types and uses of well completion tools such as hangers and packers. This provides these tools with insertion, setting, and hydraulic reverse-release functions, improving the tool's versatility. While maintaining a modular and universal design, structural optimization integrates a downward-rotating release function and a cyclic release function to enhance the reliability of tool insertion.

[0004] This application discloses a multi-functional branch well service tool, which adopts the following technical solution:

[0005] A multi-functional integrated branch well service tool includes an inner tubing string and an outer tubing string, which are connected together.

[0006] The inner tubing includes an upper connector, a flow channel sleeve, a pull-out sleeve, an upper connecting sleeve, a lower connecting sleeve, a rotating shaft sleeve, a tubing adapter sleeve, an inner central tube, a pressure isolation sleeve, a sealing insert, an extension tube, and a central tube ball seat.

[0007] The upper end of the upper connector is connected to the drill string, and the lower end is connected to the flow channel sleeve and the pull-out sleeve.

[0008] The upper end of the flow channel sleeve is inserted into the lower end of the upper connector and connected to the lower end of the upper connector. The upper and lower ends of the flow channel sleeve are respectively provided with large-volume strip-shaped circulation holes. A ball storage sleeve is installed in the flow channel sleeve, and the ball storage sleeve is pre-filled with hollow steel balls. On the insertion section of the flow channel sleeve into the upper connector, the inner wall of the upper connector has an enlarged diameter.

[0009] The upper end of the pull-out sleeve is fitted onto the lower end of the upper connector; the upper connecting sleeve is arranged in the pull-out sleeve, and the lower end of the upper connecting sleeve is connected to the release claw spring sleeve; the upper end of the lower connecting sleeve is inserted into the upper connecting sleeve and connected to the upper connecting sleeve, and the release claw spring sleeve is connected to the outer tube column.

[0010] The upper end of the lower connecting sleeve is inserted into the upper connecting sleeve and connected to it, and the lower end is inserted into the upper end of the rotating shaft sleeve and connected to it. A pressure transmission hole is provided on the wall of the lower connecting sleeve. A claw spring limiting sleeve is fitted on the outside of the lower connecting sleeve, and the claw spring limiting sleeve is fitted on the pressure transmission hole to seal the upper and lower sides of the pressure transmission hole. A locking ring pressure cap is fitted on the upper end of the claw spring limiting sleeve, and a groove is provided on the locking ring pressure cap. The locking ring is fitted into the groove of the locking ring pressure cap, and the claw spring limiting sleeve and the release claw spring sleeve are fixed with copper scissor nails.

[0011] The tubular adapter sleeve is fitted into the lower end of the rotating shaft sleeve and connected to the rotating shaft pressure cap;

[0012] The upper end of the inner central tube is inserted into the pipe column adapter sleeve and connected to the lower end of the pipe column adapter sleeve; the lower end of the inner central tube is inserted into the upper end of the pressure isolation sleeve and connected to the pressure isolation sleeve.

[0013] The upper end of the pressure isolation sleeve is fitted onto the lower end of the inner central tube and connected to the inner central tube, while the lower end is fitted onto the sealing tube and connected to the upper end of the sealing tube. A pressure isolation ball seat is arranged inside the pressure isolation sleeve. An overflow hole is opened on the outer wall of the pressure isolation sleeve, and when the pressure isolation ball seat is arranged on the pressure isolation sleeve, it blocks the overflow hole. The middle position inside the pressure isolation sleeve is a boss structure. After the pressure isolation ball seat is installed into the pressure isolation sleeve, the large diameter of the lower split position of the pressure isolation ball seat is in close contact with the inner diameter of the boss of the pressure isolation sleeve.

[0014] The upper end of the sealing tube is connected to the pressure isolation sleeve, and the lower end is connected to the extension tube. The upper end of the extension tube is inserted into the sealing tube, and the lower end is reduced in diameter. A central tube pressure cap is fitted into the small diameter of the lower end of the extension tube. The lower end of the extension tube is inserted into the central tube ball seat. A groove is opened on the outer wall of the extension tube, and a central tube retaining ring is installed in the groove. The central tube retaining ring is arranged on the lower side of the inner central tube and between the central tube ball seat and the extension tube.

[0015] The central tube ball seat is fitted into the lower end of the extension tube and connected to the central tube cap;

[0016] The outer tubing is used to connect the outer tubing functional module.

[0017] Preferably, the outer tubing includes a directional return sleeve, a return sleeve conversion sleeve, a return sleeve support sleeve, a release cylinder, a flap valve connecting sleeve, a flap valve housing, an insertion sealing sleeve, an outer tubing connecting sleeve, and an outer tubing pressure cap.

[0018] The rotary drum adapter sleeve is connected to the lower end of the positioning return cylinder, and the upper end of the rotary drum adapter sleeve is inserted into the positioning return cylinder; the lower end of the return cylinder connecting sleeve is connected to the return cylinder support sleeve.

[0019] The return sleeve support is connected to the release claw spring sleeve. When connected, the lower end of the return sleeve support is threaded to the release cylinder, and the lower end of the release cylinder is threaded to the flap valve connecting sleeve. The upper end of the flap valve connecting sleeve is inserted into the lower end of the release cylinder.

[0020] The flap valve connecting sleeve is connected to the flap valve housing, and the flap valve housing is connected to the flap valve connecting sleeve; threads are provided at the lower end of the flap valve housing and the upper end of the insertion tube sealing cylinder for connecting the outer tube column functional module;

[0021] The outer tube connecting sleeve is inserted into the insertion tube sealing cylinder and connected to the outer tube column pressure cap. The lower end of the outer tube connecting sleeve is connected to the lower connector.

[0022] Preferably, a flap valve cover is installed on the flap valve seat, the lug of the flap valve cover engages with the lug on the upper end face of the flap valve seat, aligning the hole on the lug, and a torsion spring and a fixing pin are inserted into the lug hole to fix the flap valve cover and the flap valve seat.

[0023] Preferably, a soluble cap core is provided on the flap valve cover, and the flap valve cover and the soluble cap core are threaded together.

[0024] Preferably, the ball storage sleeve adopts a segmented structure with an internal groove. The hollow steel ball is embedded into the internal groove of the ball storage sleeve by the elastic expansion of the segmented claws.

[0025] Preferably, the tubular adapter sleeve has a structure that is larger at the top and smaller at the bottom.

[0026] Preferably, a lower transmission claw is installed at the lower end of the pull-out sleeve; an upper transmission claw with the same structure as the lower transmission claw is provided at the upper end of the upper connecting sleeve. The upper transmission claw is fitted into the upper end of the upper connecting sleeve and fixed to the upper connecting sleeve by welding. The upper transmission claw and the lower transmission claw are arranged opposite to each other.

[0027] Preferably, the lower end of the lower connecting sleeve is fitted with a release piston, and the release piston is fixed together with the rotating shaft sleeve using copper scissors.

[0028] Preferably, a top ball sleeve, a small spring, and a small spring cap are sequentially inserted into the lower part of the central tube ball seat. The small spring cap is threadedly connected to the central tube ball seat, and the top ball sleeve is inserted into the lower end of the central tube ball seat.

[0029] Preferably, the top of the directional return tube is an arc-shaped guide slope; a strip-shaped positioning groove is opened at the end of the arc-shaped slope; a positioning key is provided on the outer wall of the upper connector.

[0030] The beneficial effects of this invention are:

[0031] (1) The tool adopts a modular design. As a service tool module, various specifications of packers and hangers can be connected to it, making the tool versatile and applicable.

[0032] (2) The tool adopts a concentric double-tube structure with inner and outer tubes. The inner and outer tube strings are lowered together. In the initial state, the pressure between the inner and outer tubes is separated. The pressure in the inner tube will not interfere with the tool on the outer tube, supporting high-pressure operation inside the tube. At the same time, it integrates a flow channel conversion mechanism, which can also support large-volume circulation inside the tube in the circulation flow channel state. These features allow the multi-functional integrated branch well service tool assembly to be directly connected to the sand control, fracturing or gravel packing completion string and lowered into the well, and directly carry out reservoir stimulation operation without the need to separately run the main wellbore completion and treatment string, which greatly improves construction efficiency and reduces operating costs.

[0033] (3) The tool can be cyclically inserted during the insertion process and supports the pressing and rotating card release function, making the insertion function more reliable.

[0034] (4) The tool integrates hydraulic reverse double release mechanism to ensure normal operation of the release function.

[0035] (5) The inserted tubing is allowed to be connected to the MWD. ​​After the large flow channel of the tool is activated, the orientation of the positioning keyway on the positioning return tube of the tool can be measured by the MWD. ​​After one positioning, the special guide surface of the positioning return tube can provide downhole automatic positioning and orientation services for other branch wells without the need for separate drilling or repeated drilling to measure the orientation, thus simplifying the construction steps.

[0036] (6) The tool also integrates a main wellbore temporary plugging mechanism. After being released, the main wellbore space can be automatically plugged without the need for additional plugging devices. Furthermore, soluble materials are introduced, and the plugging can be automatically released after the soluble materials dissolve. There is no need to drill down separately to connect the main and branch wellbores, further improving construction efficiency. Attached Figure Description

[0037] Other features, objects, and advantages of this application will become more apparent from the following detailed description of non-limiting embodiments with reference to the accompanying drawings:

[0038] Figure 1 is a schematic diagram of the multi-functional branch well service tool in this embodiment;

[0039] Figure 2 is a schematic diagram of the first part of the multi-functional branch well service tool in this embodiment;

[0040] Figure 3 is a schematic diagram of the second part of the multifunctional branch well service tool in this embodiment;

[0041] Figure 4 is a schematic diagram of the third part of the multifunctional branch well service tool in this embodiment;

[0042] Figure 5 is a schematic diagram of the fourth part of the multifunctional branch well service tool in this embodiment;

[0043] Figure 6 is a schematic diagram of the fifth part of the multi-functional branch well service tool in this embodiment;

[0044] Figure 7 is a schematic diagram of the sixth part of the multifunctional branch well service tool in this embodiment;

[0045] Figure 8 is a schematic diagram comparing the stretched and compressed states of the multi-functional branch well service tool in this embodiment.

[0046] Explanation of reference numerals in the attached diagram: 1. Inner tubing; 101. Upper connector; 1011. Centralizing ring; 1012. Positioning key; 102. Flow channel sleeve; 1021. Ball storage sleeve; 1022. Hollow steel ball; 103. Pull-out sleeve; 1031. Lower transmission torsion claw; 104. Upper connecting sleeve; 1041. Upper transmission torsion claw; 1042. Release claw spring sleeve; 105. Lower connecting sleeve; 1051. Claw spring limiting sleeve; 1052. Locking ring pressure cap; 1053. Release piston; 106. Rotary shaft sleeve; 1061. Rotary shaft retaining ring; 1062. Rotary shaft pressure cap; 107. Tubing adapter sleeve; 108. Inner central tube; 109. Pressure isolation sleeve; 1091. 1. Pressure isolation ball seat; 110. Sealing insert; 111. Extension tube; 1111. Central tube pressure cap; 1112. Central tube retaining ring; 112. Central tube ball seat; 1121. Top ball sleeve; 1122. Small spring; 1123. Small spring pressure cap; 2. Outer tube column; 201. Directional return sleeve; 202. Return sleeve conversion sleeve; 2021. Locking cap; 203. Return sleeve support sleeve; 204. Release cylinder; 205. Flip valve connecting sleeve; 206. Flip valve housing; 2061. Flip valve seat; 2062. Flip valve cover; 207. Insertion tube sealing sleeve; 208. Outer tube connecting sleeve; 209. Outer tube column pressure cap; 210. Lower connector. Detailed Implementation

[0047] The present application will now be described in further detail with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are for illustrative purposes only and are not intended to limit the invention. Furthermore, it should be noted that, for ease of description, only the parts relevant to the invention are shown in the accompanying drawings.

[0048] It should be noted that, unless otherwise specified, the embodiments and features described in this application can be combined with each other. This application will now be described in detail with reference to the accompanying drawings and embodiments.

[0049] The present invention provides a multi-functional branch well service tool. Referring to FIG1, the multi-functional branch well service tool includes an inner tubing string 1 and an outer tubing string 2, which are connected together.

[0050] Referring to Figures 2-7, the inner tube column 1 includes an upper connector 101, a flow channel sleeve 102, a pull-out sleeve 103, an upper connecting sleeve 104, a lower connecting sleeve 105, a rotating shaft sleeve 106, a tube column adapter sleeve 107, an inner central tube 108, a pressure isolation sleeve 109, a sealing insert 110, an extension tube 111, and a central tube ball seat 112.

[0051] A centering ring 1011 is fitted on the outer wall of the upper connector 101, and a positioning key 1012 is also fitted on the outer wall of the upper connector 101. The positioning key 1012 is used for positioning when the inner tubing 1 and the outer tubing 2 are connected. The upper end of the upper connector 101 is connected to the drill string, and the lower end is connected to the flow channel sleeve 102 and the pull-out sleeve 103.

[0052] The upper end of the flow channel sleeve 102 is inserted into the lower end of the upper connector 101 and threadedly connected to the lower end of the upper connector 101. The flow channel sleeve 102 has high-capacity strip-shaped circulation holes at its upper and lower ends, namely the upper circulation hole and the lower circulation hole, respectively. A ball storage sleeve 1021, containing hollow steel balls 1022, is installed within the flow channel sleeve 102. At the insertion section of the flow channel sleeve 102 into the upper connector 101, the inner wall of the upper connector 101 has an enlarged diameter, allowing fluid within the flow channel sleeve 102 to flow out through the upper circulation hole of the flow channel sleeve 102. This allows the fluid to smoothly pass through the annulus between the upper connector 101 and the flow channel sleeve 102 and continue flowing downwards. The ball storage sleeve 1021 adopts a segmented structure with an internal groove. The hollow steel ball 1022 is embedded into the internal groove of the ball storage sleeve 1021 by using the elastic expansion of the segmented claws. Then, the ball storage sleeve 1021 is inserted into the middle of the flow channel sleeve 102. After the groove at the upper end of the ball storage sleeve 1021 is aligned with the hole in the middle of the flow channel sleeve 102, the ball storage sleeve 1021 and the flow channel sleeve 102 are fixed by installing scissor pins in the hole. Then, the flow channel sleeve 102 is inserted into the lower end of the upper connector 101 and connected by threads to complete the connection between the flow channel sleeve 102 and the upper connector 101.

[0053] The upper end of the pull-out sleeve 103 is fitted onto the lower end of the upper connector 101, and the upper connector 101 is threadedly connected to the pull-out sleeve 103, with a flush transition on the outer wall. An expanded diameter section is formed at the upper end of the pull-out sleeve 103, and a lower transmission torque claw 1031 is installed at the lower end of the pull-out sleeve 103. The lower end of the pull-out sleeve 103 is threaded to the lower transmission torque claw 1031, which is located inside the lower end of the pull-out sleeve 103. The end of the lower transmission torque claw 1031 has a groove, and the uncut portion of the head is shaped like a waist-shaped triangular pyramid.

[0054] The upper connecting sleeve 104 is arranged in the pull-out sleeve 103, and its upper end is provided with an upper up torque claw 1041, which has the same structure as the lower up torque claw 1031. The upper up torque claw 1041 is fitted into the upper end of the upper connecting sleeve 104 and fixed to the upper connecting sleeve 104 by welding. The upper up torque claw 1041 and the lower up torque claw 1031 are arranged opposite to each other. After the upper up torque claw 1041 and the lower up torque claw 1031 come into contact with each other, the protruding keys of each other will be guided into the keyway of the other by the guiding effect of the triangular cone shape of the head. The lower end of the upper connecting sleeve 104 has two threaded surfaces, an inner and an outer thread. The inner thread connects to the lower connecting sleeve 105, and the outer thread connects to the release claw spring sleeve 1042. The release claw spring sleeve 1042 is used to connect the inner tube column 1 and the outer tube column 2 together.

[0055] The upper end of the lower connecting sleeve 105 is inserted into the upper connecting sleeve 104 and threadedly connected to it. The lower end is inserted into the upper end of the rotating bushing 106 and threadedly connected to it. A pressure transmission hole is formed in the bore wall of the lower connecting sleeve 105. Furthermore, a claw spring limiting sleeve 1051 is fitted on the outer side of the lower connecting sleeve 105, which is fitted onto the pressure transmission hole and seals both the upper and lower sides of the pressure transmission hole. A locking ring cap 1052 is fitted onto the upper end of the claw spring limiting sleeve 1051. The locking ring cap 1052 is threadedly connected to the claw spring limiting sleeve 1051, and a groove is provided on the locking ring cap 1052. The locking ring is fitted into the groove of the locking ring cap 1052. The connected locking ring cap 1052, locking ring, and claw spring limiting sleeve 1051 are then inserted into the split threaded claw at the lower end of the release claw spring sleeve 1042, aligning the groove of the claw spring limiting sleeve 1051 with the threaded hole in the middle of the release claw spring sleeve 1042. The claw spring limiting sleeve 1051 and the release claw spring sleeve 1042 are then fixed together with brass rivets. A release piston 1053 is fitted onto the lower end of the lower connecting sleeve 105, and the release piston 1053 is fixed together with the rotating shaft sleeve 106 with brass rivets.

[0056] The lower outer wall of the rotating bushing 106 has a groove, and a C-shaped rotating shaft retaining ring 1061 is embedded in the groove of the rotating bushing 106. A rotating shaft pressure cap 1062 is fitted on the rotating bushing 106, and the rotating shaft pressure cap 1062 is arranged on the upper side of the rotating shaft retaining ring 1061.

[0057] The tubing adapter sleeve 107 is fitted into the lower end of the rotating shaft sleeve 106 and threadedly connected to the rotating shaft cap 1062. The lower end of the tubing adapter sleeve 107 is threadedly connected to the inner center tube 108 via an oil pipe. The tubing adapter sleeve 107 has a structure that is larger at the top and smaller at the bottom. The smaller diameter end can be inserted into the flap valve connecting sleeve 205 of the outer tubing 2, while the larger diameter end contacts and limits the flap valve connecting sleeve 205, transferring the weight of all the inner tubing 1 at the bottom of the tubing adapter sleeve 107 to the outer tubing 2, with the outer tubing 2 supporting the load. The lower end of the lower connecting sleeve 105 is inserted into the tubing adapter sleeve 107, but no direct threaded connection is established with the tubing adapter sleeve 107. The total weight of the lower inner tubing 1 is not loaded on the lower connecting sleeve 105, so the left-hand thread of the release claw spring sleeve 1042 will not bear the downward pull force, avoiding excessive downward pressure that could cause excessive rotational resistance of the left-hand thread of the release claw spring sleeve 1042, resulting in thread sticking. A C-shaped opening rotary shaft retainer 1061 is embedded in the groove at the lower end of the rotating shaft sleeve 106. After the bushing 106 is inserted into the tubing adapter sleeve 107, the rotating shaft retainer 1061 is also inserted into the expanded diameter section at the upper end of the tubing adapter sleeve 107. The insertion distance is longer than the length of the left-hand thread of the release claw spring sleeve 1042. The upper end of the tubing adapter sleeve 107 is threadedly connected to the rotating shaft pressure cap 1062. During the rotation and disengagement of the left-hand thread of the release claw spring sleeve 1042, the upper connecting sleeve 104, the release claw spring sleeve 1042, the lower connecting sleeve 105, and the rotating shaft sleeve 106 will move upward together. After the left-hand thread is completely separated, the tubing is lifted up, and the rotating shaft retainer 1061 moves upward together. When it contacts and is limited by the inner step of the rotating shaft pressure cap 1062, the lifting force is transmitted through the rotating shaft pressure cap 1062 to the tubing adapter sleeve 107 and all the inner tubing 1 at the bottom, and all the inner tubing 1 are pulled out of the wellbore together.

[0058] The upper end of the inner central tube 108 is inserted into the tubing adapter sleeve 107 and connected to the lower end of the tubing adapter sleeve 107 via an oil pipe thread. The lower end of the inner central tube 108 is inserted into the upper end of the pressure isolation sleeve 109 and connected to the pressure isolation sleeve 109 via a thread.

[0059] The upper end of the pressure isolation sleeve 109 is fitted onto the lower end of the inner central tube 108 and connected to it. The lower end is fitted onto the sealing insert 110 and threadedly connected to its upper end. A pressure isolation ball seat 1091 is arranged inside the pressure isolation sleeve 109 and secured to it with copper scissor pins. An overflow hole is formed on the outer wall of the pressure isolation sleeve 109, and the pressure isolation ball seat 1091 blocks this hole when positioned on the sleeve. The lower end of the pressure isolation ball seat 1091 has a funnel-shaped interior and a small radial diameter to a large diameter exterior. The lower end of the pressure isolation ball seat 1091 is divided into multiple segments by wire cutting. The cutting groove extends to the large diameter position at the upper end of the pressure isolation ball seat 1091. The pressure isolation sleeve 109 has a boss structure in the middle. After the pressure isolation ball seat 1091 is installed into the pressure isolation sleeve 109, the large diameter of the segmented lower end of the pressure isolation ball seat 1091 is in close contact with the inner diameter of the boss of the pressure isolation sleeve 109. The boss of the pressure isolation sleeve 109 restricts the elastic outward expansion of the segmented claws of the pressure isolation ball seat 1091. There are sealing grooves at the upper and lower ends of the large diameter of the pressure isolation ball seat 1091, located at the upper and lower ends of the flow hole of the pressure isolation sleeve 109, to prevent the pressure inside the pipe from being transmitted to the outer tube 2 through the flow hole.

[0060] The upper end of the sealing tube 110 is threadedly connected to the pressure isolation sleeve 109, and the lower end is threadedly connected to the extension tube 111 via an oil pipe. The lower end of the sealing tube 110 is fitted onto the extension tube 111.

[0061] The upper end of the extension tube 111 is inserted into the sealing tube 110, and the lower end is reduced in diameter. A central tube cap 1111 is fitted into the smaller diameter section of the lower end of the extension tube 111. The lower end of the extension tube 111 is inserted into the central tube ball seat 112. A groove is formed on the outer wall of the extension tube 111, and a C-shaped opening central tube retainer 1112 is inserted into the groove. The central tube retainer 1112 is arranged on the lower side of the inner central tube 108, and is positioned between the central tube ball seat 112 and the extension tube 111.

[0062] The central tube ball seat 112 is fitted into the lower end of the extension tube 111 and threadedly connected to the central tube pressure cap 1111. The lower part of the central tube ball seat 112 is sequentially inserted with a top ball sleeve 1121, a small spring 1122, and a small spring pressure cap 1123. The small spring pressure cap 1123 is threadedly connected to the central tube ball seat 112. The lower end of the central tube ball seat 112 is inserted into the top ball sleeve 1121, which provides upward force. The enlarged lower end of the top ball sleeve 1121 contacts and limits contact with the step of the lower inner hole of the central tube ball seat 112. A copper shear pin is inserted through the central tube ball seat 112 to connect the central tube ball seat 112 to the central tube pressure cap 1111.

[0063] The connection method of the inner tube column 1 is as follows: the straightening ring 1011 is fitted into the upper connector 101 and connected by threads. The ball storage sleeve 1021 adopts a split structure with an internal groove. The hollow steel ball 1022 is embedded into the internal groove of the ball storage sleeve 1021 by using the elastic expansion of the split claw. Then, the ball storage sleeve 1021 is inserted into the middle of the flow channel sleeve 102. After the groove at the upper end of the ball storage sleeve 1021 is aligned with the hole in the middle of the flow channel sleeve 102, the ball storage sleeve 1021 and the flow channel sleeve 102 are fixed by installing copper shear pins in the hole. Then, the flow channel sleeve 102 is inserted into the lower end of the upper connector 101 and connected by threads. The upper end of the pull sleeve 103 is threaded to the lower end of the upper connector 101. The upper torsion claw 1041 is fitted into the upper connecting sleeve 104. After fixing the upper large diameter section by end welding, insert the upper connecting sleeve 104 into the pull-out sleeve 103. The lower end of the pull-out sleeve 103 is connected to the lower transmission torsion claw 1031 by threads. The lower end of the upper connecting sleeve 104 has two threaded surfaces, inner and outer. The inner thread connects to the lower connecting sleeve 105, and the outer thread connects to the release claw spring sleeve 1042. Insert the locking ring into the groove of the locking ring pressure cap 1052. The locking ring pressure cap 1052 is threaded to the claw spring limiting sleeve 1051. Put the completed locking ring pressure cap 1052, locking ring, and claw spring limiting sleeve 1051 into the split threaded claw at the lower end of the release claw spring sleeve 1042. Align the groove of the claw spring limiting sleeve 1051 with the threaded hole in the middle of the release claw spring sleeve 1042. Use copper scissors to secure the claw spring limiting sleeve 105. 1. Fix the release gripper spring sleeve 1042, insert the release piston 1053 into the lower end of the lower connecting sleeve 105, and connect the rotating shaft sleeve 106 to the lower end of the lower connecting sleeve 105 with threads. Simultaneously, use copper scissor pins to fix the release piston 1053 and the rotating shaft sleeve 106 together. Insert the rotating shaft pressure cap 1062 into the small diameter portion of the lower end of the rotating shaft sleeve 106, and simultaneously embed a C-shaped rotating shaft retaining ring 1061 into the groove at the lower end of the rotating shaft sleeve 106. Insert the tubing adapter sleeve 107 into the lower end of the rotating shaft sleeve 106 and connect it with the rotating shaft pressure cap 1062 with threads. The lower end of the tubing adapter sleeve 107 is connected to the inner center tube 108 via an oil pipe thread. Insert the upper end of the pressure isolation sleeve 109 into the pressure isolation ball seat 1091 and fix the two together with copper scissor pins. The lower end of the rear pressure isolation sleeve 109 is connected to the inner central tube 108 via an oil pipe thread. The upper end of the sealing tube 110 is threaded to the pressure isolation sleeve 109, and the lower end is threaded to the extension tube 111 via an oil pipe thread. The small diameter part of the lower end of the extension tube 111 is fitted into the central tube pressure cap 1111. The C-shaped opening central tube retainer 1112 is installed in the groove. Then, the central tube ball seat 112 is fitted into the lower end of the extension tube 111 and threaded to the central tube pressure cap 1111. The top ball sleeve 1121, the small spring 1122, and the small spring pressure cap 1123 are inserted into the lower part of the central tube ball seat 112 in sequence. The small spring pressure cap 1123 is threaded to the central tube ball seat 112. Finally, the positioning key 1012 is installed into the keyway of the upper connector 101 and fixed with screws.

[0064] Referring to Figures 2-7, the outer tube column 2 includes a directional return sleeve 201, a return sleeve conversion sleeve 202, a return sleeve support sleeve 203, a release cylinder 204, a flap valve connecting sleeve 205, a flap valve housing 206, an insertion tube sealing sleeve 207, an outer tube connecting sleeve 208, and an outer tube column pressure cap 209.

[0065] The top of the directional return tube 201 is an arc-shaped guide slope, which is used to guide the positioning key 1012 to move along the arc surface. A strip-shaped positioning groove is opened at the end of the arc-shaped slope to accommodate the positioning key 1012. By guiding and accommodating the positioning key 1012, the positioning key 1012 can be positioned in the positioning key 1012 groove of the directional return tube 201 regardless of its initial orientation.

[0066] The rotary drum adapter sleeve is threadedly connected to the lower end of the positioning return sleeve, and the upper end of the rotary drum adapter sleeve is inserted into the positioning return sleeve. The lower end of the return sleeve is threadedly connected to the return sleeve support sleeve 203. A locking cap 2021 is installed in the rotary drum adapter sleeve, and the locking cap 2021 is inserted into the upper end of the return sleeve and fixed to the return sleeve by steel shear pins.

[0067] The return sleeve support sleeve 203 is threadedly connected to the release claw spring sleeve 1042. When connected, the lower end of the return sleeve support sleeve 203 is threadedly connected to the release cylinder 204, and the lower end of the release cylinder 204 is threadedly connected to the flap valve connecting sleeve 205. The upper end of the flap valve connecting sleeve 205 is inserted into the lower end of the release cylinder 204.

[0068] A flap valve connecting sleeve 205 is connected to a flap valve housing 206, and the flap valve housing 206 is threadedly connected to the flap valve connecting sleeve 205. A flap valve seat 2061 is installed in the flap valve housing 206, and the flap valve seat 2061 is threadedly connected to the inner wall of the flap valve housing 206. A flap valve cover 2062 is installed on the flap valve seat 2061. The lug of the flap valve cover 2062 engages with the lug on the upper end face of the flap valve seat 2061, aligning the holes on the lugs. A torsion spring and a fixing pin are inserted into the lug holes to fix the flap valve cover 2062 and the flap valve seat 2061. A soluble cap core is provided on the flap valve cover 2062, and the flap valve cover 2062 is threadedly connected to the soluble cap core. The lower end of the flap valve housing 206 and the upper end of the insertion tube sealing cylinder 207 are threaded for connecting the outer tube column 2 functional module. The outer tube column 2 functional module can be connected to different types of anchor packers according to the usage requirements. The lower end of the insertion tube sealing cylinder 207 is provided with a cross-shaped spline, and the outer tube connecting sleeve 208 connected to it has a cross keyway inside. The outer tube column pressure cap 209 is inserted into the insertion tube sealing cylinder 207 from the upper end.

[0069] The outer tube connecting sleeve 208 is inserted into the insert sealing cylinder 207 and the key engages with the keyway. Then it is threadedly connected to the outer tube column pressure cap 209. The lower end of the outer tube connecting sleeve 208 is threadedly connected to the lower connector 210.

[0070] The connection method of the outer tube column 2 is as follows: Insert the locking cap 2021 into the upper end of the return sleeve connecting sleeve and fix the two with steel shear pins. Then, thread the return sleeve connecting sleeve to the lower end of the directional return sleeve 201. Thread the lower end of the return sleeve connecting sleeve to the support sleeve of the directional return sleeve 201. Thread the lower end of the support sleeve of the directional return sleeve 201 to the release cylinder 204. Thread the lower end of the release cylinder 204 to the flap valve connecting sleeve 205. Thread the flap valve cover 2062 to the soluble cap core. Engage the lug of the flap valve cover 2062 with the lug on the upper surface of the flap valve seat 2061, aligning the holes on the lugs. Insert a torsion spring and a fixing pin into the lug holes to fix the flap valve cover 2062 and the flap valve seat 2061. Then, connect the flap valve seat 2061... The flap valve housing 206 is installed and connected by threads. Then, the flap valve housing 206 is threaded to the flap valve connecting sleeve 205. The lower end of the flap valve housing 206 and the upper end of the insertion tube sealing cylinder 207 are threaded for connecting the outer tube column 2 functional module. The outer tube column 2 functional module can be connected to different types of anchor packers according to the usage requirements. The outer tube column pressure cap 209 is inserted into the insertion tube sealing cylinder 207 from the top. The lower end of the insertion tube sealing cylinder 207 has a cross-shaped spline. The outer tube connecting sleeve 208 connected to it has a cross keyway inside. The outer tube connecting sleeve 208 is inserted into the insertion tube sealing cylinder 207 and the key engages with the keyway. Then, it is threaded to the outer tube column pressure cap 209. The lower end of the outer tube connecting sleeve 208 is threaded to the lower connector 210.

[0071] Insert the inner tube 1 into the outer tube 2. Connect the left-hand thread on the split threaded claw at the lower end of the release claw spring sleeve 1042 in the inner tube 1 to the left-hand thread at the inner diameter reduction of the support sleeve of the directional return cylinder 201 in the outer tube 2. This completes the connection and fixation between the inner tube 1 and the outer tube 2 of the service tool. Fill the annulus between the outer tube 2 and the inner tube 1 with machine oil through the filling hole at the large diameter of the release cylinder 204. Finally, install the filling hole plug on the filling hole to complete the tool assembly.

[0072] The method of using a multifunctional integrated branch well service tool disclosed in this application is as follows:

[0073] Referring to Figure 8, the upper end of the tool is connected to the MWD (Mechanical Downhole Deposition Device) for well entry. If obstruction is encountered during the running-in process, it can be pushed down and rotated to release the jamming. The principle is as follows: When the tubing is pressed down, the positioning key 1012 on the upper connector 101 will slide along the arc-shaped guide surface at the top of the directional return sleeve 201 into the positioning key 1012 groove at the end of the guide surface. At this time, the pull sleeve 103 connected to the upper connector 101 moves to the lower end along the upper connecting sleeve 104. The lower transmission torque claw 1031 and the upper transmission torque claw 1041 connected to the pull sleeve 103 and the upper connecting sleeve 104, respectively, separate, releasing the torque transmission state to the release claw spring sleeve 1042. At this time, the upper connector 101 is rotated. 01 transmits torque to the service tool outer tube column 2 through the positioning key 1012 inserted into the positioning key 1012 slot of the directional return tube 201. The various parts of the service tool outer tube column 2 are connected by threads, which transmits the torque step by step downwards along the outer tube column 2. The separable parts of the quick connector component include the insertion sealing tube 207 and the outer tube connecting sleeve 208. The insertion sealing tube 207 has a cross-shaped key at its lower end, and the upper end of the outer tube connecting sleeve 208 has a corresponding cross-shaped keyway milled inside. Through the engagement of the key and the keyway, the torque transmitted from the directional return tube 201 can be further transmitted to the lower outer tube column 2, driving the entire outer tube column 2 to rotate. If the obstruction point still cannot be overcome, the tubing can be lifted to a stretched state, and the pump can be started to circulate and flush the obstruction area. The principle is as follows: when the tubing is lifted, the upper connector 101 will move upward, and the upper connector 101, along with the flow channel sleeve 102 and the pull-out sleeve 103, will move upward together. The lower end of the pull-out sleeve 103 is connected to a downward transmission torsion claw 1031, which moves upward along with the pull-out sleeve 103. When it moves to the expanded diameter section of the upper connecting sleeve 104, the downward transmission torsion claw 1031 contacts and limits the expanded diameter section of the upper connecting sleeve 104. At this time, the insertion depth of the flow channel sleeve 102 in the upper connecting sleeve 104 is determined. In its shallowest state, the lower circulation hole of the flow channel sleeve 102 is above the insertion sealing point of the upper connecting sleeve 104. At this time, the high-speed fluid will pass through the upper circulation hole of the flow channel sleeve 102 without obstruction, and flow along the flow channel sleeve 102, the upper connector 101, and the pull sleeve 103. Then, it will re-enter the pipe through the lower circulation hole of the flow channel sleeve 102 and flow downward. The high-speed fluid will bypass the ball storage sleeve 1021 installed in the middle of the flow channel sleeve 102, and there will be no throttling pressure difference at the ball storage sleeve 1021. The ball storage sleeve 1021 will not move down to release the hollow steel ball 1022, which can realize the large-volume circulation of fluid in the pipe.

[0074] After the tool is lowered into position, keep the tool in the stretched state and open the high-volume circulation channel. At this time, the pressure of the inner tube 1 and the outer tube 2 is isolated. Circulation or pressurization can be performed according to the requirements of the operation. The principle of pressure isolation is as follows: all parts related to the inner tube 1 and the inner cavity of the service tool are equipped with seals at the threaded connections. The internal pressure generated during the high-volume circulation process will be blocked, and the internal pressure of the inner tube 1 of the service tool will not be transmitted outward. There are flow holes evenly distributed on the outer side of the small diameter position of the pressure isolation sleeve 109, and a pressure isolation ball seat 1091 is installed on the inner side. The inner end is funnel-shaped, and the outer end changes from a small radial diameter to a large diameter. The lower end of the complete rotating body of the isolation ball seat is divided into multiple segments by wire cutting. The cutting groove extends to the large diameter position of the upper end of the isolation ball seat. The middle position of the pressure isolation sleeve 109 is a boss structure. After the isolation ball seat is installed into the pressure isolation sleeve 109, the large diameter of the lower segment position is in close contact with the inner diameter of the boss. The boss restricts the elastic expansion of the segment claws. There are sealing grooves at the upper and lower ends of the large diameter of the isolation ball seat, located at the upper and lower ends of the flow hole of the pressure isolation sleeve 109, to prevent the pressure inside the pipe from being transmitted to the outer pipe column 2 through the flow hole and to isolate the pressure inside and outside the pipe.

[0075] When a functional module requiring a seat connection in the middle of the tool needs to be connected, the tubing needs to be changed to a pressurized state, the flow channel changed, and the displacement increased to release the hollow steel ball 1022 pre-placed in the tool. The hollow steel ball 1022 simultaneously opens the flow hole between the inner and outer tubes, and finally, the hollow steel ball 1022 sets and seals, providing hydraulic driving force for the outer tubing 2 functional module. The principle of these actions is as follows: the upper connector 101 connects the flow channel sleeve 102 and the pull-out sleeve 103. The flow channel sleeve 102 has large-displacement strip-shaped circulation holes at both its upper and lower ends, and a ball storage sleeve 1021 with a pre-placed hollow steel ball 1022 installed in the middle. When the flow channel sleeve 102 is inserted into the insertion section of the upper connector 101, the upper connector 101 has an expanded diameter, allowing the fluid inside the tube to flow out from the circulation hole on the flow channel sleeve 102. It can smoothly pass through the annulus between the upper connector 101 and the flow channel sleeve 102 and continue to flow downward. The upper connecting sleeve 104 is inserted into the pull-out sleeve 103. At the same time as the upper connecting sleeve 104 is inserted, the flow channel sleeve 102 is also inserted into the inner hole of the upper connecting sleeve 104. The upper connecting sleeve 104 has an insertion sealing point at the large diameter position at the upper end, which is provided for both the pull-out sleeve 103 and the upper connecting sleeve 104. The upper end of the pull-out sleeve 103 has an expanded diameter section. When the tubing is pressed down, the upper connector 101 will insert deeper along with the pull-out sleeve 103 and the flow channel sleeve 102. The expanded diameter section of the pull-out sleeve 103 will contact and limit the inner diameter section of the arc-shaped inclined surface at the top of the directional return tube 201. At this time, the flow channel sleeve 102 is at its deepest insertion position in the upper connecting sleeve 104. 2. The lower end of the strip-shaped circulation hole will be at the lower end of the sealing point of the upper connecting sleeve 104. At this time, when the fluid in the pipe flows downward along the annulus through the upper circulation hole of the flow channel sleeve 102, it will be blocked by the sealing point of the upper connecting sleeve 104. At this time, the fluid can only flow downward through the pipe space of the flow channel sleeve 102. A ball storage sleeve 1021 is provided inside the pipe of the flow channel sleeve 102. The lower end of the ball storage sleeve 1021 has a single-sided cross-section with a hook shape. The complete rotating surface of the lower end of the ball storage sleeve 1021 is evenly divided into multiple petals by wire cutting. The depth of the groove extends through the thin-walled section, so that each petal can elastically expand outward. Through elastic expansion, it holds the hollow steel ball 1022. After the ball storage sleeve 1021 is installed in the flow channel sleeve 102, the lower end of the ball storage sleeve 1021 is in close contact with the inner boss of the flow channel sleeve 102 through the large diameter, restricting The elastic expansion of the lower end of the ball storage sleeve 1021 prevents the hollow steel ball 1022 from detaching. The high-speed fluid in the tubing passes entirely through the ball storage sleeve 1021, generating throttling pressure at the wire-cut seam. When the pressure is sufficient, it shears off the copper shear pins restricting the ball storage sleeve 1021, causing it to move downwards. The upper, larger diameter portion of the sleeve moves to the position of the inner boss in the flow channel sleeve 102, where it is limited. The inner boss no longer restricts the expansion of the lower end of the ball storage sleeve 1021's split claws. Under the influence of the throttling pressure, the hollow steel ball 1022 separates from the ball storage sleeve 1021 and moves downwards with the fluid. After release, the hollow steel ball 1022 moves downwards to the funnel opening of the funnel structure inside the isolation ball seat, where its position is restricted and it cannot descend further, simultaneously closing the fluid flow channel at the funnel opening.At this point, the high-speed fluid will generate a throttling pressure difference due to the closed flow channel. Under the pressure, the copper shear pins fixing the pressure isolation sleeve 109 and the isolation ball seat will be cut off. The isolation ball seat will descend, and the flow hole at the small diameter of the pressure isolation sleeve 109 will establish communication with the inner tube string 1 of the service tool. The large diameter of the isolation ball seat will contact and limit the contact with the boss inside the pressure isolation sleeve 109. At this time, the lower segment of the isolation ball seat is located at the expanded diameter position at the lower end of the pressure isolation sleeve 109, and the elastic expansion of the lower segment of the isolation ball seat will no longer be restricted. The hollow steel ball 1022 continues to descend and reaches the central tube ball seat 112 for sealing, generating sealing pressure that is transmitted to the outer tube string 2 through the flow hole of the pressure isolation sleeve 109.

[0076] Afterwards, the mechanical release is performed, separating the inner tubing string 1 and leaving the outer tubing string 2 and connected tools in the well. The principle of mechanical release is as follows: the upper connector 101 is threadedly connected to the pull sleeve 103, the lower end of the pull sleeve 103 is threadedly connected to the lower transmission torque claw 1031, and the upper connecting sleeve 104 is inserted into the pull sleeve 103. The upper connecting sleeve 104 has an upper transmission torque claw 1041 welded to its top. When mechanical release is required, the tubing string is lifted, and the upper connector 101 drives the pull sleeve 103 and the lower transmission torque claw 1031 to move upward along the upper connecting sleeve 104. After the upper transmission torque claw 1041 and the lower transmission torque claw 1031 come into contact with each other, the triangular cone shape of their heads will guide their respective protruding keys into the keyway of the other. During the lifting process of the upper connector 101, the positioning key 1012 will be removed from the positioning key 1012 of the directional return cylinder 201. At this time, the column rotates forward, and the torque will be transmitted downward through the upper connector 101. Through the meshing of the upper torque claw 1041 and the lower torque claw 1031, the rotational torque is transmitted to the upper connecting sleeve 104. The upper connecting sleeve 104 is connected to the release claw spring sleeve 1042 and the lower connecting sleeve 105 as a whole by threads, which will drive the release claw spring sleeve 1042 to rotate forward. The slotted thread claw at the lower part of the release claw spring sleeve 1042 has a left-hand thread. The forward rotation causes it to disengage from the left-hand thread connection point inside the support sleeve of the directional return cylinder 201, realizing mechanical release. The tubing adapter sleeve 107 has a structure that is larger at the top and smaller at the bottom. The smaller diameter end can be inserted into the flap valve connecting sleeve 205 of the service tool's outer tubing 2, while the larger diameter end contacts and limits the flap valve connecting sleeve 205, transferring the weight of all the inner tubing 1 at the bottom of the tubing adapter sleeve 107 to the outer tubing 2, with the outer tubing 2 supporting the load. The lower end of the lower connecting sleeve 105 is inserted into the tubing adapter sleeve 107, but no direct threaded connection is established with the tubing adapter sleeve 107. The total weight of the lower inner tubing 1 is not loaded onto the lower connecting sleeve 105, so the left-hand thread of the release claw spring sleeve 1042 will not bear the downward pull force, avoiding excessive downward pressure that could cause excessive rotational resistance of the left-hand thread of the release claw spring sleeve 1042, leading to thread sticking. A C-shaped opening rotary shaft retainer 1061 is embedded in the groove at the lower end of the rotary shaft sleeve 106. After the rotating bushing 106 is inserted into the tubing adapter sleeve 107, the rotating shaft retainer 1061 is also inserted into the expanded diameter section at the upper end of the tubing adapter sleeve 107. The insertion distance is longer than the length of the left-hand thread of the release claw spring sleeve 1042. The upper end of the tubing adapter sleeve 107 is threadedly connected to the rotating shaft pressure cap 1062. During the rotation and disengagement of the left-hand thread of the release claw spring sleeve 1042, the upper connecting sleeve 104, the release claw spring sleeve 1042, the lower connecting sleeve 105, and the rotating bushing 106 will move upward together. After the left-hand thread is completely separated, the tubing is lifted up, and the rotating shaft retainer 1061 moves upward together. When it contacts and is limited by the inner step of the rotating shaft pressure cap 1062, the lifting force is transmitted through the rotating shaft pressure cap 1062 to the tubing adapter sleeve 107 and all the inner tubing 1 at the bottom, and all the inner tubing 1 are pulled out of the wellbore together.

[0077] The hydraulic release mechanism works as follows: When the pressure isolation sleeve 109's flow hole opens and the hollow steel ball 1022 descends to the central tube ball seat 112 for sealing, the pressure of the inner tube column 1 can be transmitted to the annulus between the inner tube column 1 and the outer tube column 2 of the service tool. The release piston 1053 has sealing points both inside and outside, establishing a seal at the top. The sealing tube 110 in the inner tube column 1 is inserted into the sealing tube sleeve 207 of the outer tube column 2, establishing a seal at the bottom. The upper and lower sealing points create a sealed pressure chamber between the inner tube column 1 and the outer tube column 2 of the service tool. The pressure within the chamber provides hydraulic sealing force to the functional module of the outer tube column 2 installed in this area. When the pressure is high enough, the release piston is secured. The copper shear pins of the plug 1053 and the rotating bushing 106 are cut off. The release piston 1053 moves upward under hydraulic pressure, impacting the claw spring limiting sleeve 1051, thus cutting off the copper shear pins that fix the impact claw spring limiting sleeve 1051 and the release claw spring sleeve 1042. The release piston 1053 drives the claw spring limiting sleeve 1051 to move upward as well. The lower end of the release claw spring sleeve 1042 has a slotted, segmented structure. Each segment undergoes elastic deformation after being subjected to radial force. Before the claw spring limiting sleeve 1051 moves, its insertion and engagement with the release claw spring sleeve 1042 is a tight fit, restricting the inward retraction of the segmented claws of the claw spring limiting sleeve 1051. When the claw spring limiting sleeve 1051 is... After the release piston 1053 is pushed away, it moves to the limit position at the inner diameter step of the upper end of the release claw spring sleeve 1042. At this time, the small diameter position of the upper end of the release piston 1053 is exactly located at the split claw of the release claw spring sleeve 1042. The unsplit claw retracts to provide space. The thread of the split claw is a triangular thread with a triangular tooth profile. When subjected to the hydraulic axial thrust provided by the release piston 1053, it will generate an inward contraction force, causing the left-hand male thread of the release claw spring sleeve 1042 to retract and separate from the reverse thread connection point of the support sleeve of the directional return cylinder 201, realizing the hydraulic release function. At the same time, during the upward movement of the claw spring limit sleeve 1051, it will drive the lock embedded in it. As the ring moves upward, it reaches the limit position. The locking ring then falls into the narrowed diameter position of the straight step at the upper end of the lower connecting sleeve 105, restricting the retraction of the claw spring limit sleeve 1051. The claw spring limit sleeve 1051 has two sets of sealing points inside. In the initial state, it isolates the signal hole in the middle of the lower connecting sleeve 105. At the same time, after the claw spring limit sleeve 1051 moves upward, the signal hole will disengage from the area sealed by the two sealing points. At this time, the pressure of the inner tube column 1 will be transmitted outward through the signal hole. There are no sealing points above the lower connecting sleeve 105, so it can establish communication with the sleeve annulus. The liquid in the inner tube changes from a pressurized state to a pressure relief signal and then to a circulating flow state, which is used to indicate that the hydraulic release mechanism has completed its work.

[0078] During the removal of the inner tube 1, no liquid lock effect occurs, preventing the tube from being difficult to remove. The principle for releasing the liquid lock is as follows: the lower end of the central tube ball seat 112 is fitted with the top ball sleeve 1121, which is provided with an upward force by the small spring 1122. The expanded diameter of the lower end of the top ball sleeve 1121 contacts and limits the contact with the inner hole step of the lower end of the central tube ball seat 112. When the hollow steel ball 1022 falls, it first contacts the small diameter end of the top ball sleeve 1121. The pressure generated by the high-speed fluid pushes the hollow steel ball 1022 to overcome the elastic force of the small spring 1122 and continue to fall until it contacts the funnel-shaped inclined surface inside the central tube ball seat 112, generating... Contact sealing enables the hollow steel ball 1022 to be seated and sealed. After depressurization, there will be no pressure difference between the upper and lower surfaces of the hollow steel ball 1022. The small spring 1122 pushes the hollow steel ball 1022 upward, pushing it away from the sealing surface of the central tube ball seat 112, thus releasing the seated sealing state of the hollow steel ball 1022. Furthermore, a square groove-shaped flow channel is machined on the small diameter end face of the top ball sleeve 1121. The pressure on the upper and lower surfaces of the steel ball is balanced, and a flow channel is established. When the inner tubing 1 of the service tool is being raised, liquid lock will not be generated due to the hollow steel ball 1022 being seated continuously, thus preventing the inner tubing 1 from being raised out of the wellbore.

[0079] After the inner tubing string 1 is pulled out, the lower branch wellbore and the upper branch wellbore will be automatically isolated. They can be automatically reconnected later. The principle behind this function is as follows: After the service tool inner tubing string 1 is released, the flap valve cover 2062 and the soluble cap core are threaded together to form a cover structure. A torsion spring controls the opening and closing of the cover structure. Before the service tool inner tubing string 1 is released, the flap valve cover 2062 is limited by the inner central tube 108 in the inner tubing string 1, preventing it from closing and remaining in a normally open state. After mechanical or hydraulic release, the inner central tube 108 is pulled out of the wellbore, and the torsion spring forces the flap valve cover 2062... 2. The cover is closed, and the cover is fitted with the inner chamfered edge of the upper end face of the flap valve seat 2061. The inner chamfered edge of the flap valve seat 2061 is embedded with a rubber sealing ring, which contacts and seals with the flap valve cover 2062, isolating the pressure of the well section above the flap valve cover 2062 and the soluble cover core, thus realizing the functions of pressure separation and temporary plugging in the pipe. The soluble valve core can be made of aluminum-magnesium alloy, which can slowly self-dissolve in the drilling fluid or completion fluid environment. Alternatively, it can be made of easily acid-corroded cast iron material, which can be dissolved by injecting acid into the soluble valve core. After the soluble valve core is dissolved, the sealing isolation of the flap valve cover 2062 is released, and the upper and lower parts are connected.

[0080] The tool's positioning and orientation function works as follows: The top of the outer tubing 2 has a directional return tube 201. The top of the directional return tube 201 has an arc-shaped guide slope for guiding the positioning key 1012 along the arc. A strip-shaped positioning groove is cut at the end of the arc-shaped slope to house the positioning key 1012. By guiding and housing the positioning key 1012, regardless of its initial orientation, the final orientation of the positioning key 1012 is always the orientation of the positioning key 1012 groove in the directional return tube 201. The multi-functional integrated branch well service tool assembly can circulate at a high flow rate within the tubing. A MWD is connected to the upper end of the upper connector 101. By circulating and activating the MWD, the orientation of the positioning key 1012 can be measured. Based on the uniqueness of the positioning key 1012's position after insertion into the directional return tube 201, the orientation of the directional return tube 201 can be determined. The directional return tube 201 remains downhole after the service tool inner tubing 1 is released from the 1 positioning key 1012 slot. If the return tool needs to be automatically positioned and oriented downhole, it can be directly inserted into the well after installing a positioning key 1012 of the same width at the wellhead. There is no need to measure the return tool's orientation downhole again. The lower end of the directional return tube 201 is screwed to the return tube connecting sleeve. A locking cap 2021 is inserted into the return tube connecting sleeve. The return tube connecting sleeve and the locking cap 2021 are fixed by steel shear studs. The locking cap 2021 has an internal toothed buckle with the right-angled edge facing down, which can provide an anchor point for the return tool and prevent the return tool from being pushed out of the directional return tube 201 prematurely. The steel shear studs provide anchoring force. If the return tool needs to be retrieved, an upward load is applied to cut the steel shear studs, and the return tool, along with the locking cap 2021, is pulled out of the wellbore.

[0081] The term "comprising" or any other similar term is intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus / device that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent in such process, method, article, or apparatus / device.

[0082] The technical solution of the present invention has been described above with reference to the preferred embodiments shown in the accompanying drawings. However, it will be readily understood by those skilled in the art that the scope of protection of the present invention is obviously not limited to these specific embodiments. Without departing from the principles of the present invention, those skilled in the art can make equivalent changes or substitutions to the relevant technical features, and the technical solutions after these changes or substitutions will all fall within the scope of protection of the present invention.

Claims

1. A multifunctional integrated branch well service tool, characterized in that: The system includes an inner tubing (1) and an outer tubing (2), which are connected together. The inner tubing (1) includes an upper connector (101), a flow channel sleeve (102), a pull-out sleeve (103), an upper connecting sleeve (104), a lower connecting sleeve (105), a rotating bushing (106), a tubing adapter sleeve (107), an inner central tube (108), a pressure isolation sleeve (109), a sealing insert (110), an extension tube (111), and a central tube ball seat (112). The upper end of the upper connector (101) is connected to the drill string, and the lower end is connected to the flow channel sleeve (102) and the pull-out sleeve (103). The upper end of the flow channel sleeve (102) is inserted into the lower end of the upper connector (101) and connected to the lower end of the upper connector (101). The upper and lower ends of the flow channel sleeve (102) are respectively provided with large-capacity strip-shaped circulation holes. A ball storage sleeve (1021) is installed in the flow channel sleeve (102), and a hollow steel ball (1022) is pre-filled in the ball storage sleeve (1021). The flow channel sleeve (102) is inserted into the upper connector (101) at the insertion section, and the inner wall of the upper connector (101) has an enlarged diameter. The upper end of the pull sleeve (103) is sleeved on the lower end of the upper connector (101). The upper connecting sleeve (104) is arranged in the pull sleeve (103), and the lower end of the upper connecting sleeve (104) is connected to the release claw spring sleeve (1042). The upper end of the lower connecting sleeve (105) is inserted into the upper connecting sleeve (104) and connected to the upper connecting sleeve (104). The release claw spring sleeve (1042) is connected to the outer tube column (2). The lower connecting sleeve (105) is inserted into the upper connecting sleeve (104) at its upper end and connected to the upper connecting sleeve (104), and inserted into the upper end of the rotating shaft sleeve (106) at its lower end and connected to the rotating shaft sleeve (106); a pressure transmission hole is provided on the wall of the lower connecting sleeve (105); a claw spring limiting sleeve (1051) is fitted on the outside of the lower connecting sleeve (105), and the claw spring limiting sleeve (1051) is fitted on the pressure transmission hole to seal the upper and lower sides of the pressure transmission hole; a locking ring pressure cap (1052) is fitted on the upper end of the claw spring limiting sleeve (1051), and a groove is provided on the locking ring pressure cap (1052). The locking ring is fitted into the groove of the locking ring pressure cap (1052), and the claw spring limiting sleeve (1051) and the release claw spring sleeve (1042) are fixed with copper scissors; the tube The column adapter sleeve (107) is fitted into the lower end of the rotating shaft sleeve (106) and connected to the rotating shaft pressure cap (1062); the upper end of the inner central tube (108) is inserted into the column adapter sleeve (107) and connected to the lower end of the column adapter sleeve (107); the lower end of the inner central tube (108) is inserted into the upper end of the pressure isolation sleeve (109) and connected to the pressure isolation sleeve (109); the upper end of the pressure isolation sleeve (109) is fitted onto the lower end of the inner central tube (108) and connected to the inner central tube (108), and the lower end is fitted onto the sealing insert (110) and connected to the upper end of the sealing insert (110); a pressure isolation ball seat (1091) is arranged inside the pressure isolation sleeve (109);An overflow hole is provided on the outer wall of the pressure isolation sleeve (109), and the overflow hole is blocked when the pressure isolation ball seat (1091) is arranged on the pressure isolation sleeve (109); the middle position of the inside of the pressure isolation sleeve (109) is a boss structure. After the pressure isolation ball seat (1091) is installed into the pressure isolation sleeve (109), the large diameter of the lower end of the pressure isolation ball seat (1091) is in close contact with the inner diameter of the boss of the pressure isolation sleeve (109); the upper end of the sealing tube (110) is connected to the pressure isolation sleeve (109), and the lower end is connected to the extension tube (111); the upper end of the extension tube (111) is inserted into the sealing tube (110), and the lower end is retracted. The extension tube (111) is fitted with a central tube cap (1111) at the smaller diameter of its lower end; the lower end of the extension tube (111) is inserted into the central tube ball seat (112); a groove is provided on the outer wall of the extension tube (111), and a central tube retaining ring (1112) is installed in the groove. The central tube retaining ring (1112) is arranged on the lower side of the inner central tube (108), and the central tube retaining ring (1112) is arranged between the central tube ball seat (112) and the extension tube (111); the central tube ball seat (112) is fitted into the lower end of the extension tube (111) and connected to the central tube cap (1111); the outer tube column (2) is used to connect the functional module of the outer tube column (2).

2. The multifunctional integrated branch well service tool according to claim 1, characterized in that: The outer tube column (2) includes a directional return tube (201), a return tube conversion sleeve (202), a return tube support sleeve (203), a release cylinder (204), a flap valve connecting sleeve (205), a flap valve housing (206), an insertion tube sealing sleeve (207), an outer tube connecting sleeve (208), and an outer tube column pressure cap (209); the rotary drum conversion sleeve is connected to the lower end of the positioning return tube, and the upper end of the rotary drum conversion sleeve is inserted into the positioning return tube; the lower end of the return tube connecting sleeve is connected to the return tube support sleeve (203); the return tube support sleeve (203) is connected to the release claw spring sleeve (1042), and when connected, the lower end of the return tube support sleeve (203) is threaded. Connect the drop cylinder (204), and thread the lower end of the drop cylinder (204) to the flap valve connecting sleeve (205); insert the upper end of the flap valve connecting sleeve (205) into the lower end of the drop cylinder (204); the flap valve connecting sleeve (205) is connected to the flap valve housing (206), and the flap valve housing (206) is connected to the flap valve connecting sleeve (205); the lower end of the flap valve housing (206) and the upper end of the insertion tube sealing cylinder (207) are threaded for connecting the outer tube column (2) functional module; insert the outer tube connecting sleeve (208) into the insertion tube sealing cylinder (207) and connect it to the outer tube column pressure cap (209); the lower end of the outer tube connecting sleeve (208) is connected to the lower connector (210).

3. The multifunctional integrated branch well service tool according to claim 1, characterized in that: A flap valve cover (2062) is installed on the flap valve seat (2061). The lug of the flap valve cover (2062) engages with the lug on the upper end face of the flap valve seat (2061) to align the hole on the lug. A torsion spring and a fixing pin are inserted into the lug hole to fix the flap valve cover (2062) and the flap valve seat (2061).

4. The multifunctional integrated branch well service tool according to claim 1, characterized in that: A soluble cap core is provided on the flap valve cover (2062), and the flap valve cover (2062) is threadedly connected to the soluble cap core.

5. The multifunctional integrated branch well service tool according to claim 1, characterized in that: The ball storage sleeve (1021) adopts a segmented structure with an internal groove. The hollow steel ball (1022) is embedded into the internal groove of the ball storage sleeve (1021) by using the elastic expansion of the segmented claws.

6. The multifunctional integrated branch well service tool according to claim 1, characterized in that: The tubular adapter sleeve (107) has a structure that is larger at the top and smaller at the bottom.

7. The multifunctional integrated branch well service tool according to claim 1, characterized in that: A lower transmission claw (1031) is installed at the lower end of the pull-out sleeve (103); an upper transmission claw (1041) with the same structure as the lower transmission claw (1031) is provided at the upper end of the upper connecting sleeve (104). The upper transmission claw (1041) is fitted into the upper end of the upper connecting sleeve (104) and fixed to the upper connecting sleeve (104) by welding. The upper transmission claw (1041) and the lower transmission claw (1031) are arranged opposite to each other.

8. The multifunctional integrated branch well service tool according to claim 1, characterized in that: The lower end of the lower connecting sleeve (105) is fitted with a release piston (1053), and the release piston (1053) is fixed together with the rotating bushing (106) using copper scissors.

9. The multifunctional integrated branch well service tool according to claim 1, characterized in that: The lower part of the central tube ball seat (112) is sequentially inserted with a top ball sleeve (1121), a small spring (1122), and a small spring cap (1123). The small spring cap (1123) is threadedly connected to the central tube ball seat (112), and the lower end of the central tube ball seat (112) is inserted with a top ball sleeve (1121).

10. The multifunctional integrated branch well service tool according to claim 1, characterized in that: The top of the directional return tube (201) is an arc-shaped guide slope; a strip-shaped positioning groove is opened at the end of the arc-shaped slope; a positioning key (1012) is provided on the outer wall of the upper connector (101).

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