A four-stage diverging well tool system and a method for building a well

Abstract

The application aims to provide a four-stage branch well tool system and a well building method, to realize efficient and high-quality construction of the branch well, and to solve the problems of complex technical scheme and inaccurate orientation of the positioning tool of the traditional branch well tool; to achieve the above-mentioned purpose, the solving method of the application is to provide a four-stage branch well tool system, which comprises an anchoring orientation device, an integrated recyclable windowing device, a combined drilling tool and a branch well prefabricated window device, the anchoring orientation device is arranged in a main borehole, the anchoring orientation device is used to realize the positioning of the branch well, the integrated recyclable windowing device is used for the windowing operation of the branch well, the combined drilling tool is used to manufacture the branch well, and the branch well prefabricated window device is arranged at a branch opening of the main borehole, and the branch well prefabricated window device is used to realize the reentry function of the branch well.

Description

Technical Field

[0001] This invention relates to the field of branch well technology, and in particular to a four-stage branch well tool system and its well construction method. Background Technology

[0002] Branch well technology is one of the important means to reduce the development cost of oil and gas wells and improve the recovery rate. This technology involves drilling several branches in a main wellbore to maximize the drainage area, expose the oil and gas reservoir, and increase the production of a single well. Branch well technology can make the most of the wellhead, reduce the land occupation, reduce the drilling rig usage time and the amount of supporting pipes and drilling fluid used, thereby significantly reducing the reservoir development cost.

[0003] Level 4 branch well technology possesses all the functions of level 1 to 3 branch well technology, with complete technical functions. It can also carry out post-production enhancement measures or well workover operations on each branch, with a large margin for post-operation, which is conducive to extending the life of branch wells and further increasing oil and gas well production.

[0004] The practical application of four-stage branch well technology is currently limited due to its numerous construction steps, high operational difficulty, and complex re-entry process for each branch well. This is mainly reflected in: overly complex technical solutions, numerous supporting tools, and high construction risks; insufficient anchoring force of positioning tools leading to inaccurate positioning and orientation; irregular window openings in the directional drilling tools, making them difficult to retrieve; and difficulties in constructing the branch interface support system. Therefore, conducting relevant research on four-stage branch well technology is of great significance for the application and development of branch wells, as well as for cost reduction, efficiency improvement, and enhanced oil recovery.

[0005] CN113482532A discloses a branch well construction equipment and method. The branch well construction equipment includes multiple completion devices, with one completion device corresponding to each of the multiple branch wells formed by the main well branching. The completion devices are fixedly connected to the well wall of the branch wells and can play a good role in sand control. The guiding component of the completion device is exactly positioned at the drilling location of the next branch well to be drilled. Therefore, when drilling the next branch well, the drill bit of the drilling equipment can drill along the guiding slope of the guiding component until the designed well depth is reached. Positioning is convenient and can ensure that the position of the drilled branch well is accurate and the inclination angle meets the requirements. However, it has problems such as multiple construction steps and high operation difficulty.

[0006] Therefore, providing a four-level branch well tool system and its well construction method in the field of branch well technology is an urgent technical problem to be solved. Summary of the Invention

[0007] The purpose of this invention is to provide a four-stage branch well tool system and its well construction method, so as to achieve high-efficiency and high-quality construction of branch wells and solve the problems of complex technical solutions and inaccurate orientation of positioning tools in traditional branch well tools.

[0008] To achieve the above objectives, the present invention provides a four-stage branch well tool system, comprising: an anchoring and directional device, an integrated retrievable window opening device, a combined drilling tool, and a branch well prefabricated window device. The anchoring and directional device is located in the main wellbore and is used to locate the branch well. The integrated retrievable window opening device is used for opening the branch well. The combined drilling tool is used to manufacture the branch well. The branch well prefabricated window device is located at the fork in the main wellbore and is used to enable the re-entry function of the branch well.

[0009] Furthermore, the anchoring and directional device includes: a positioning and directional joint, an anchoring packer, and a ceramic isolation valve, wherein the positioning and directional joint, the anchoring packer, and the ceramic isolation valve are detachably connected sequentially from end to end; preferably, the anchoring packer has bidirectional slips, which are connected to the well wall to prevent the anchoring packer from falling off and rotating.

[0010] Furthermore, the anchoring and directional device can be connected to either the feeding tool or the integrated retrievable window opening device. When the directional device is connected to the feeding tool, the feeding tool is used to transport the directional device in the main wellbore. When the directional device is connected to the integrated retrievable window opening device, the branch well window is positioned. Preferably, the positioning and directional joint is provided with a directional guide keyway, which is used to adjust the direction of the integrated retrievable window opening device.

[0011] Furthermore, the integrated recyclable window opening device includes: an integrated milling cone and an angled window opening tool, the angled window opening tool being mounted on the positioning and orientation joint, the integrated milling cone being used for branch well window opening operations, and the angled window opening tool being used to guide the integrated milling cone into the working position; preferably, the integrated milling cone is welded with imported high-performance alloy, and the cone blade structure and button alloy combination improve work efficiency.

[0012] Furthermore, the inclined window opening tool includes: a retrievable inclined device, a chip-blocking connector, and an anchoring and positioning tool, which are connected sequentially from end to end. The anchoring and positioning tool is used to connect with the positioning and orientation connector, and the retrievable inclined device is used to guide the integrated milling cone for branch well window opening operations. Preferably, the anchoring and positioning tool uses an elastic claw structure for positioning, and the bottom surface of the anchoring and positioning tool is provided with a gear structure that cooperates with the directional guide keyway on the positioning and orientation connector to adjust the direction of the directional guide keyway. Preferably, the inclined window opening tool is retrieved by an inclined device retrieval tool, which is retrieved using a fishing hook or a fishing cylinder.

[0013] Furthermore, the prefabricated window device for the branch well includes an inner tubing string and an outer tubing string. The inner tubing string is located inside the outer tubing string. The inner tubing string is equipped with a wall-mounting mechanism and a driving device. The outer tubing string is equipped with a prefabricated window. The driving device is used to control the opening and closing of the wall-mounting mechanism. The wall-mounting mechanism faces the prefabricated window and cooperates with it. When open, the wall-mounting mechanism passes through the prefabricated window and is fixed at the junction of the main wellbore and the branch well. Preferably, the wall-mounting mechanism is equipped with a hook, which can be fixed at the junction of the main wellbore and the branch well.

[0014] Furthermore, the outer tube string also includes: a suspension packer, a positioning hanger, a rotary joint, and a tailpipe string, wherein the suspension packer, the positioning hanger, the prefabricated window, the rotary joint, and the tailpipe string are connected in sequence.

[0015] Furthermore, the driving device is a hydraulic feeding tool.

[0016] Furthermore, the four-stage branch well tool system also includes: a main wellbore re-entry tool and a branch well re-entry tool. The main wellbore re-entry tool is a hollow pipe structure with open ends. The branch well re-entry tool is a hollow pipe structure with a closed bottom and an opening on its side for engaging with a branch well window. Preferably, the main wellbore re-entry tool and the branch well re-entry tool are inserted and retrieved via a small drill pipe or coiled tubing.

[0017] A well construction method for a four-stage branch well tool system includes: S1: After the main wellbore operation is completed, the tool is sent into the well to insert the anchoring and directional device. The anchoring packer is pressurized and set to seal the main wellbore. The positioning and directional joint is used to adjust the predetermined orientation of the branch wellbore opening, and the tool is then taken out. S2: The integrated retrievable window opening device is inserted into the well, and the anchoring and positioning tool is connected to the positioning and orientation joint. The orientation of the retrievable directional device is changed by adjusting the direction of the directional guide keyway on the positioning and orientation joint. The integrated milling cone performs branch well window opening operation through the guidance of the retrievable directional device. After the operation is completed, the integrated milling cone leaves the main wellbore. S3: The combined drilling tool is used to drill into the branch wellbore, drill to the designed well depth, and then the drill string is pulled out of the well. S4: The drill pipe is lowered into the directional diverter recovery tool, which is connected to the recyclable directional diverter to recover the recyclable directional diverter; S5: The prefabricated window device of the branch well is put into the well, the tailpipe string enters the branch well, the drive device controls the wall hanging mechanism to open, the hook of the wall hanging mechanism opens and is fixed at the junction of the main well and the branch well to realize window positioning, and the suspension packer and positioning hanger are pressed to fix the outer string string. S6: Close the wall-mounted mechanism and lift the drive device to pull the inner tubing out of the well; S7: Select the main wellbore and branch well using either the main wellbore re-entry tool or the branch well re-entry tool. The main wellbore re-entry tool enters the main wellbore through a small drill pipe and stops at the window of the branch well, with the pipe wall sealing the window of the branch well. The branch well re-entry tool enters the main wellbore through a small drill pipe and stops at the window of the branch well, with an opening on its side to cooperate with the window of the branch well.

[0018] Advantages of this invention: 1. The operation steps are simple, the required tools are few, efficiency is improved, and costs are reduced; 2. The anchoring and orientation device can achieve precise positioning; 3. The prefabricated window device for the branch well adopts an embedded wall-mounted mechanism, which is more durable and less prone to damage. Attached Figure Description

[0019] Figure 1 This is a schematic diagram of step S1 of a well-building method for a four-stage branch well tool system provided by the present invention; Figure 2 This is a schematic diagram of step S2 of a well-building method for a four-stage branch well tool system provided by the present invention; Figure 3 This is a schematic diagram of step S3 of a well-building method for a four-stage branch well tool system provided by the present invention; Figure 4 This is a schematic diagram of step S4 of a well-building method for a four-stage branch well tool system provided by the present invention; Figure 5 This is a schematic diagram of step S5 of a well-building method for a four-stage branch well tool system provided by the present invention; Figure 6 This is a schematic diagram of step S5 of a well-building method for a four-stage branch well tool system provided by the present invention; Figure 7 This is a schematic diagram of a branch well re-entry tool for a four-stage branch well tool system provided by the present invention.

[0020] Figure 8 This is a schematic diagram of the main wellbore re-entry tool of a four-stage branch well tool system provided by the present invention.

[0021] As shown in the figure, 1. Anchoring and directional device, 2. Insertion tool, 3. Positioning and directional connector, 4. Anchoring packer, 5. Ceramic isolation valve, 6. Integrated retrievable window opening device, 7. Integrated milling cone, 8. Retrievable directional guide, 9. Chip guard connector, 10. Anchoring and positioning tool, 11. Combined drill string, 12. Directional guide retrieval tool, 13. Branch well prefabricated window device, 14. Suspended packer, 15. Positioning hanger, 16. Prefabricated window, 17. Wall-mounted mechanism, 18. Rotary joint, 19. Tailpipe string, 20. Drive device, 21. Branch well re-entry tool, 22. Main wellbore re-entry tool. Detailed Implementation

[0022] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings.

[0023] A four-stage branch well tool system includes: an anchoring and directional device 1, an integrated retrievable window opening device 6, a combined drill string 11, and a branch well prefabricated window device 13. The anchoring and directional device 1 is located in the main wellbore and is used to locate the branch well. The integrated retrievable window opening device 6 is used for opening the branch well. The combined drill string 11 is used to manufacture the branch well. The branch well prefabricated window device 13 is located at the fork in the main wellbore and is used to enable the re-entry function of the branch well.

[0024] like Figure 1 As shown, the anchoring and directional device 1 includes: a positioning and directional connector 3, an anchoring packer 4, and a ceramic isolation valve 5. The positioning and directional connector 3, the anchoring packer 4, and the ceramic isolation valve 5 are detachably connected sequentially from head to tail. The anchoring packer 4 has bidirectional slips, which are connected to the well wall to prevent the anchoring packer 4 from falling off and rotating.

[0025] like Figure 2 and Figure 4As shown, the anchoring and directional device 1 is connected to the integrated retrievable window opening device 6. When the directional device is connected to the integrated retrievable window opening device 6, the branch well window is positioned. The positioning and directional connector 3 is provided with a directional guide keyway, which is used to adjust the direction of the integrated retrievable window opening device 6. The integrated retrievable window opening device 6 includes: an integrated milling cone 7 and an oblique window opening tool. The oblique window opening tool is located on the positioning and directional connector 3. The integrated milling cone 7 is used for branch well window opening operations, and the oblique window opening tool is used to guide the integrated milling cone 7 into the working position. The integrated milling cone 7 is welded with imported high-performance alloy, and the cone blade structure and button alloy combination enhance the lifting effect. Work efficiency; the inclined window opening tool includes: a retrievable inclined device 8, a chip-blocking connector 9, and an anchoring and positioning tool 10, which are connected sequentially from head to tail. The anchoring and positioning tool 10 is used to connect with the positioning and orientation connector 3. The retrievable inclined device 8 is used to guide the integrated milling cone 7 to perform branch well window opening operations. The anchoring and positioning tool 10 adopts an elastic claw structure for positioning. The bottom surface of the anchoring and positioning tool 10 is provided with a gear structure that cooperates with the orientation guide keyway on the positioning and orientation connector 3 to adjust the direction of the orientation guide keyway. The inclined window opening tool is retrieved by an inclined device retrieval tool 12, which is retrieved by a fishing hook or a fishing tube.

[0026] like Figure 5 and Figure 6 As shown, the prefabricated window device 13 for the branch well includes an inner tubing string and an outer tubing string. The inner tubing string is located inside the outer tubing string. The inner tubing string is equipped with a wall-mounting mechanism 17 and a drive device 20. The outer tubing string is equipped with a prefabricated window 16. The drive device 20 is used to control the opening and closing of the wall-mounting mechanism 17. The wall-mounting mechanism 17 faces the prefabricated window 16 and cooperates with it. When open, the wall-mounting mechanism 17 passes through the prefabricated window 16 and is fixed at the junction of the main wellbore and the branch well. The wall-mounting mechanism 17 is equipped with a hook, which can be fixed at the junction of the main wellbore and the branch well. The outer tubing string also includes a suspension packer 14, a positioning hanger 15, a rotary joint 18, and a tailpipe string 19. The suspension packer 14, the positioning hanger 15, the prefabricated window 16, the rotary joint 18, and the tailpipe string 19 are connected in sequence. The drive device 20 is a hydraulic insertion tool.

[0027] like Figure 7 and Figure 8As shown, the four-stage branch well tool system also includes: a main wellbore re-entry tool 22 and a branch well re-entry tool 21. The main wellbore re-entry tool 22 is a hollow pipe structure with open ends. The branch well re-entry tool 21 is a hollow pipe structure with a closed bottom and an opening on its side for engaging with a branch well window. Preferably, the main wellbore re-entry tool 22 and the branch well re-entry tool 21 are inserted and retrieved via a small drill pipe or coiled tubing.

[0028] like Figures 1-8 As shown, a well construction method for a four-stage branch well tool system is characterized by comprising: S1: After the main wellbore operation is completed, the tool 2 is sent into the well to insert the anchoring and directional device 1. The anchoring packer 4 is pressurized and set to seal the main wellbore. The positioning and directional connector 3 is used to adjust the predetermined orientation of the branch wellbore opening, and the tool 2 is taken out. S2: The integrated retrievable window opening device 6 is inserted into the well, and the anchoring and positioning tool 10 is connected with the positioning and orientation joint 3. The orientation of the retrievable directional device 8 is changed by adjusting the direction of the orientation guide keyway on the positioning and orientation joint 3. The integrated milling cone 7 performs branch well window opening operation through the guidance of the retrievable directional device 8. After the operation is completed, the integrated milling cone 7 leaves the main wellbore. S3: Drill the branch wellbore with the combined drilling tool 11, drill to the designed well depth, and pull out of the well. S4: The drill pipe is lowered into the directional tool recovery tool 12, which is connected to the recyclable directional tool to recover the recyclable directional tool; S5: The prefabricated window device 13 of the branch well is inserted into the well, the tailpipe string 19 enters the branch well, the drive device 20 controls the wall-mounted mechanism 17 to open, the hook of the wall-mounted mechanism 17 is opened and fixed at the junction of the main wellbore and the branch well to achieve window positioning, and the suspension packer 14 and the positioning hanger 15 are pressed to fix the outer string string. S6: Close the wall-mounted mechanism 17 and lift the drive device 20 to pull the inner tubing out of the well; S7: The main wellbore and the branch well are selected for operation by using the main wellbore re-entry tool 22 or the branch well re-entry tool 21 respectively. The main wellbore re-entry tool 22 enters the main wellbore through a small drill pipe and stops at the window of the branch well, and the pipe wall seals the window of the branch well. The branch well re-entry tool 21 enters the main wellbore through a small drill pipe and stops at the window of the branch well. The side of the branch well re-entry tool 21 has an opening that matches the window of the branch well.

[0029] Obviously, the described embodiments are only some, not all, of the embodiments of the present invention. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without inventive effort are within the scope of protection of the present invention.

Claims

1. A four-stage branch well tool system, characterized in that, include: The system comprises an anchoring and directional device (1), an integrated retrievable window opening device (6), a combined drilling tool (11), and a branch well prefabricated window device (13). The anchoring and directional device (1) is located in the main wellbore and is used to locate the branch well. The integrated retrievable window opening device (6) is used for opening the branch well. The combined drilling tool (11) is used to manufacture the branch well. The branch well prefabricated window device (13) is located at the fork in the main wellbore and is used to enable the re-entry function of the branch well. The prefabricated window device (13) for the branch well includes an inner tubing string and an outer tubing string. The inner tubing string is located inside the outer tubing string. The inner tubing string is provided with a wall-mounting mechanism (17) and a driving device (20). The outer tubing string is provided with a prefabricated window (16). The driving device (20) is used to control the opening and closing of the wall-mounting mechanism (17). The wall-mounting mechanism (17) faces the prefabricated window (16) and cooperates with it. When the wall-mounting mechanism (17) is open, it passes through the prefabricated window (16) and is fixed at the junction of the main wellbore and the branch well.

2. The four-stage branch well tool system according to claim 1, characterized in that, The anchoring and directional device (1) includes: a positioning and directional connector (3), an anchoring packer (4), and a ceramic isolation valve (5), which are detachably connected sequentially from beginning to end.

3. A four-stage branch well tool system according to claim 2, characterized in that, The anchoring and directional device (1) can be connected to the delivery tool (2) or the integrated retrievable window opening device (6) respectively. When the directional device is connected to the delivery tool (2), the delivery tool (2) is used to transport the directional device in the main wellbore. When the directional device is connected to the integrated retrievable window opening device (6), the branch well window is positioned.

4. A four-stage branch well tool system according to claim 3, characterized in that, The integrated recyclable window opening device (6) includes: an integrated milling cone (7) and an angled window opening tool. The angled window opening tool is located on the positioning and orientation joint (3). The integrated milling cone (7) is used for branch well window opening operations, and the angled window opening tool is used to guide the integrated milling cone (7) into the working position.

5. A four-stage branch well tool system according to claim 4, characterized in that, The inclined window opening tool includes: a retrievable inclined device (8), a chip-blocking connector (9), and an anchoring and positioning tool (10). The retrievable inclined device (8), the chip-blocking connector (9), and the anchoring and positioning tool (10) are connected sequentially from head to tail. The anchoring and positioning tool (10) is used to connect with the positioning and orientation connector (3). The retrievable inclined device (8) is used to guide the integrated milling cone (7) to perform branch well window opening operations.

6. A four-stage branch well tool system according to claim 5, characterized in that, The outer tube string also includes: a suspension packer (14), a positioning hanger (15), a rotary joint (18), and a tailpipe string (19), wherein the suspension packer (14), the positioning hanger (15), the prefabricated window (16), the rotary joint (18), and the tailpipe string (19) are connected in sequence.

7. A four-stage branch well tool system according to claim 6, characterized in that, The drive device (20) is a hydraulic feeding tool.

8. A four-stage branch well tool system according to claim 7, characterized in that, Also includes: The main wellbore re-entry tool (22) and the branch well re-entry tool (21) are provided. The main wellbore re-entry tool (22) is a hollow pipe structure with open ends. The branch well re-entry tool (21) is a hollow pipe structure with a closed bottom and an opening on the side for cooperating with the branch well window.

9. A well-drilling method for a four-stage branch well tool system as described in any one of claims 1-8, characterized in that, include: S1: After the main wellbore operation is completed, the tool (2) is sent into the well to insert the anchoring and orientation device (1) and seal the main wellbore; the positioning and orientation joint (3) is used to adjust the predetermined orientation of the branch wellbore opening and the tool (2) is taken out. S2: The integrated recyclable window opening device (6) is inserted into the well, and the anchoring and positioning tool (10) is connected with the positioning and orientation joint (3). The branch well window opening operation is carried out through the integrated milling cone (7), and then the integrated milling cone (7) leaves the main wellbore. S3: The combined drilling tool (11) is used to drill into the branch wellbore, drilled to the designed well depth, and then pulled out of the well. S4: Drill pipe is lowered into the directional tool recovery tool (12) to recover the recyclable directional tool; S5: The prefabricated window device (13) of the branch well is put into the well, the tail pipe string (19) enters the branch well, the drive device (20) controls the wall hanging mechanism (17) to open to realize window positioning, and pressurize the seat hanging packer (14) and the positioning hanger (15). S6: Close the wall-mounted mechanism (17), and the inner tubing string exits the well; S7: Select the main wellbore and the branch well using the main wellbore re-entry tool (22) or the branch well re-entry tool (21), respectively.

Images