Milling fishing device and using method thereof
By designing a milling and retrieval device that combines a working cylinder and a wire bundle assembly, milling and retrieval are integrated, solving the problem that existing technologies require milling and retrieval to be performed in separate steps, thus improving construction efficiency and reducing costs.
Patent Information
- Application Number
- CN202411150261.1
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2024-08-21
- Publication Date
- 2026-03-03
AI Technical Summary
In existing technologies, the milling and retrieval processes require two separate runs of tubing, resulting in low construction efficiency and high costs.
Design a milling and fishing device, including a working cylinder and a wire bundle assembly. The wire bundle assembly cooperates with the fishing section to form a fishing cavity, realizing the integration of milling and fishing. The milling section rotates to mill impurities on the inner wall of the well and the wire bundle assembly grabs small objects that have fallen.
The milling and retrieval processes can be completed in one run of the tubing, reducing construction steps, saving construction costs, and the structure is simple and easy to use.
Smart Images
Figure CN121593697A_ABST
Abstract
Description
Technical Field
[0001] This invention relates to the field of downhole tools for petroleum engineering, and in particular to a milling and fishing device and its method of use. Background Technology
[0002] Drilling cement plugs is a common procedure in well workover operations in oil systems. However, before any work can begin, the wellbore wall must be cleaned of impurities and debris from the cement plug until it meets the required standards. Currently, there are several techniques for milling to clean the wellbore wall and retrieve standard-sized debris. However, these techniques require two separate runs of tubing for both milling and retrieval, resulting in low efficiency and increased costs. Summary of the Invention
[0003] The purpose of this invention is to provide a milling and retrieval device and its usage method, so as to alleviate the technical problem that the milling and retrieval processes need to be performed separately in related technologies.
[0004] To solve the above-mentioned technical problems, the technical solution provided by the present invention is as follows:
[0005] In a first aspect, the milling and fishing device provided by the present invention includes: a working cylinder and a wire bundle assembly;
[0006] The working cylinder is open at both ends and includes a fixedly connected connecting section, a retrieval section, and a milling section in sequence. The inner diameter of the connecting section is smaller than the inner diameter of the retrieval section. The filament bundle group consists of multiple clusters of filament bundles distributed circumferentially along the retrieval section. One end of each cluster of filament bundles is fixed to the side wall of the retrieval section, and the other end extends in a direction close to the axis of the retrieval section and is distributed in a fan shape.
[0007] Furthermore, the filament bundle group is provided in multiple groups;
[0008] Multiple sets of the wire bundles are spaced apart along the axial direction of the milling section;
[0009] In the circumferential direction of the milling section, the clusters of the multiple sets of filament bundles are staggered.
[0010] Furthermore, the filament bundle group is provided in at least three groups;
[0011] The other end of each cluster of filaments in the middle filament bundle extends toward the connecting section, while the other end of each cluster of filaments in the remaining filament bundle groups extends in a direction perpendicular to the axial direction of the milling section.
[0012] Furthermore, the filament bundle is made of steel wire.
[0013] Furthermore, one end of the salvage section is provided with a first female thread, which is a tubular thread;
[0014] The connecting section is provided with a first male thread that is adapted to the first female thread, and is connected to the salvage section through the first male thread and the first female thread.
[0015] Furthermore, the end of the salvage section away from the connecting section is provided with a second female thread, which is a tubular thread;
[0016] The milling section is provided with a second male thread that is compatible with the second female thread, and is connected to the salvage section through the second male thread and the second female thread.
[0017] Furthermore, the free end of the connecting section is provided with a third female thread for connection with the oil pipe;
[0018] Except for the free end, the diameter of the connecting section is not greater than the inner diameter of the oil pipe to which it is connected.
[0019] Furthermore, the end face of the milling section away from the retrieval section is a plane, and a YD alloy block is welded onto the plane;
[0020] Alternatively, the end face of the milling section away from the retrieval section is provided with serrated teeth, the serrated teeth extending circumferentially along the milling section, and a YD alloy block is welded on it.
[0021] Secondly, the method of using the milling and retrieval device provided by the present invention is based on the milling and retrieval device described above, and includes the following steps in sequence;
[0022] S1: Connect the milling and retrieval device to the oil pipe to form a tubing string. Then, lower the milling and retrieval device to a position 3 meters above the obstruction point at the standard tubing string speed.
[0023] S2: Connect the backwash well pipeline, turn on the circulation pump on the cement truck, and circulate the well for washing.
[0024] S3: While circulating the well, rotate and lower the tubing string, and increase the circulation pump discharge when the casing is milled to 5 meters from the top of the cement plug.
[0025] S4: While circulating and washing the well, continue to rotate and lower the tubing string, and pay attention to changes in the suspended weight. After reaching the location of the fallen object, carry out milling and retrieval operations.
[0026] S5: Stop lowering the tubing column when the milling depth reaches 1.5 meters;
[0027] S6: Raise the tubing 2 meters, rotate and lower the tubing back to the first retrieval position to complete the second retrieval operation;
[0028] S7: Stop the pump and remove the backwash pipeline one week after well washing;
[0029] S8: Limit the speed of lifting out the milling and retrieval device, and the lifting process must not involve sudden stops or releases.
[0030] Furthermore, during the entire milling and retrieval process, the pressure applied should not exceed 3000 kg, and the well-washing cycle should not be stopped for more than 5 minutes.
[0031] In summary, the technical effects achieved by the milling and fishing device provided by this invention are as follows:
[0032] In this milling and retrieval device, the connecting section is used to convey well-washing fluid and drop small items such as small-diameter pipes and rods; the retrieval section cooperates with the wire bundle assembly, and the inner cavity between the wire bundle assembly and the connecting section forms the retrieval cavity. The wire bundle assembly can trap small items with an outer diameter larger than the inner diameter of the connecting section, so that the small items are stored in the retrieval cavity; when the working cylinder rotates and is lowered, the milling section performs rotating milling on the bottom of the well.
[0033] In application, select a suitable size milling and retrieval device based on the inner wall of the well being constructed and the condition of the fallen object. Lower the milling and retrieval device to the required position in the well and perform milling while circulating the fluid. Use the milling section to cut off the impurities on the inner wall of the well, and the impurities will return to the surface with the well washing fluid. During retrieval, under the carrying action of the high-pressure well washing fluid, small fallen objects will enter the retrieval chamber. At this time, the platform formed by the wire bundle will prevent small fallen objects from falling into the well. Small fallen objects such as pipes and rods will be caught by the wire bundle when passing through the wire bundle, thus achieving retrieval.
[0034] As can be seen, compared with existing technologies, this milling and retrieval device can complete both milling and retrieval operations in a single run of the tubing, reducing construction steps and saving construction costs. Furthermore, this milling and retrieval device has a simple structure and is easy to use. Attached Figure Description
[0035] To more clearly illustrate the specific embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the specific embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of the present invention. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.
[0036] Figure 1 This is a schematic diagram of the structure of the milling and fishing device provided in an embodiment of the present invention.
[0037] Icons: 1-Working cylinder; 11-Connecting section; 12-Retrieving section; 13-Milling section; 111-First male thread; 112-Third female thread; 121-First female thread; 122-Second female thread; 131-Second male thread; 132-Serrated tooth;
[0038] 2-Fiber bundle group. Detailed Implementation
[0039] 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. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. The components of the embodiments of the present invention described and shown in the accompanying drawings can generally be arranged and designed in various different configurations.
[0040] Therefore, the following detailed description of the embodiments of the invention provided in the accompanying drawings is not intended to limit the scope of the claimed invention, but merely to illustrate selected embodiments of the invention. All other embodiments obtained by those skilled in the art based on the embodiments of the invention without inventive effort are within the scope of protection of the invention.
[0041] The following detailed description of some embodiments of the present invention is provided in conjunction with the accompanying drawings. Unless otherwise specified, the following embodiments and features can be combined with each other.
[0042] Currently, there are many technologies for milling to clean impurities from the inner wall of the wellbore and to retrieve various standard-sized objects. However, the milling and retrieval processes require two separate runs of tubing, resulting in low construction efficiency and increased construction costs.
[0043] In view of this, the present invention provides a milling and retrieval device, including a working cylinder 1 and a wire bundle group 2; the working cylinder 1 is open at both ends and includes, along its axial direction, a connecting section 11, a retrieval section 12 and a milling section 13 that are fixedly connected, wherein the inner diameter of the connecting section 11 is smaller than the inner diameter of the retrieval section 12; the wire bundle group 2 is composed of multiple clusters of wire bundles distributed circumferentially along the retrieval section 12 and spaced apart from the connecting section 11, one end of each cluster of wire bundles is fixed to the side wall of the retrieval section 12, and the other end extends in a direction close to the axis of the retrieval section 12 and is distributed in a fan shape, and the other ends of the multiple clusters of wire bundles enclose to form a flow channel.
[0044] In this milling and retrieval device, the connecting section 11 is used to convey the well washing fluid and to drop small items such as small-diameter pipes and rods; the retrieval section 12 cooperates with the wire bundle group 2, and the inner cavity between the wire bundle group 2 and the connecting section 11 forms the retrieval cavity. The wire bundle group 2 can hold small items with an outer diameter larger than the inner diameter of the connecting section 11, so that the small items are stored in the retrieval cavity; when the working cylinder 1 rotates and is lowered, the milling section 13 performs rotating milling on the bottom of the well.
[0045] During application, a suitable milling and retrieval device of appropriate size is selected according to the inner wall of the well being constructed and the condition of the fallen object. The milling and retrieval device is then lowered to the required position in the well, and milling is performed while circulating the fluid. The milling section 13 is used to cut off the impurities on the inner wall of the well, and the impurities are returned to the surface with the well washing fluid. During retrieval, under the carrying action of the high-pressure well washing fluid, small fallen objects will enter the retrieval chamber. At this time, the platform formed by the wire bundle group 2 will prevent small fallen objects from falling into the well. Small fallen objects such as pipes and rods will be caught by the wire bundle when passing through the wire bundle group 2, thus achieving retrieval.
[0046] As can be seen, compared with existing technologies, this milling and retrieval device can complete both milling and retrieval operations in a single run of the tubing, reducing construction steps and saving construction costs. Furthermore, this milling and retrieval device has a simple structure and is easy to use.
[0047] The following combination Figure 1 The structure and shape of the milling and fishing device provided in this embodiment are described in detail below:
[0048] Regarding filament bundle 2, specifically:
[0049] refer to Figure 1 The filament bundle group 2 is provided in multiple groups. Optionally, the filament bundle group 2 is provided in three groups, and each group contains four clusters of filament bundles. In the axial direction of the milling section 13, the multiple filament bundle groups 2 are distributed at intervals. In the circumferential direction of the milling section 13, the clusters of filament bundles in the multiple filament bundle groups 2 are distributed in an interlaced manner.
[0050] Preferably, the wire bundle group 2 is connected to the lower half of the retrieval section 12. Each bundle of wire in the wire bundle group 2 is made of flexible steel wire. Specifically, for the middle wire bundle group 2, each bundle contains 12-18 steel wires, specifically 12, 15 or 18, with a wire diameter of 0.5-1 mm, specifically 0.5 mm, 0.8 mm or 1 mm. For the other wire bundle groups 2, each bundle contains 12-18 steel wires, specifically 12, 15 or 18, with a wire diameter of 0.3-0.5 mm, specifically 0.3 mm, 0.4 mm or 0.5 mm.
[0051] Following the above, as Figure 1 As shown, for the middle wire bundle group 2, in each cluster, one end of the steel wire is welded to the retrieval section 12, and the other end extends obliquely upward; for the remaining wire bundle groups 2, in each cluster, one end of the steel wire is welded to the retrieval section 12, and the other end extends horizontally; for each wire bundle group 2, the steel wire forms a platform with a central channel to block small objects of unknown shape and material from falling.
[0052] During the specific connection process, for different wire bundle groups 2, straight and angled through holes are drilled at predetermined positions on the side wall of the retrieval section 12. The wire bundles are then inserted, and welded to the outer wall of the retrieval section 12. The weld protrusion from the outer wall of the retrieval section 12 is no more than 1 mm. After welding, the wires are spread into a fan shape to facilitate the passage of falling objects. This design ensures the firmness and strength of the wire bundle connection.
[0053] In practical applications, the inner cavity of the retrieval section 12 located above the wire bundle group 2 is the retrieval chamber, which is used to retain small items with an outer diameter larger than the inner diameter below the connecting section 11, or items that cannot be carried out of the well by the well washing fluid, as well as small-diameter pipes and rods. The middle wire bundle group 2 can hold small-diameter pipes and rods. The lower wire bundle group 2 can make up for the omissions caused by the upper wire bundle group 2, ensuring the effectiveness of retrieval.
[0054] Preferably, the upper and lower ends of the salvage section 12 are provided with a first female thread 121 and a second female thread 122, both of which are pipe threads. Correspondingly, the lower end of the connecting section 11 is provided with a first male thread 111 that is adapted to the first female thread 121. The connecting section 11 is fixedly connected to the salvage section 12 through the first male thread 111 and the first female thread 121. The upper end of the milling section 13 is provided with a second male thread 131 that is adapted to the second female thread 122. The milling section 13 is fixedly connected to the salvage section 12 through the second male thread 131 and the second female thread 122.
[0055] The above design satisfies the requirements for connection strength and sealing level between the salvage section 12 and the connecting section 11, as well as the requirements for connection strength and sealing level between the salvage section 12 and the milling section 13.
[0056] In this embodiment, reference Figure 1 The free end, i.e. the upper end, of the connecting section 11 is provided with a third female thread 112 for connecting with the oil pipe to achieve effective connection with the oil pipe. Except for the free end, the diameter of the hole of the connecting section 11 is not greater than the inner diameter of the oil pipe to which it is connected. In this way, the situation of thin wall caused by pursuing a large through hole for ease of processing is avoided, and the strength of the connecting section 11 is guaranteed.
[0057] Furthermore, the end face of the milled section 13 furthest from the retrieval section 12 is a plane, on which a YD alloy block is welded; or, as... Figure 1 As shown, the end face of the milling section 13 away from the retrieval section 12 is provided with serrated teeth 132. The serrated teeth 132 extend circumferentially along the milling section 13 and are welded with YD alloy blocks.
[0058] With the above design, the working cylinder 1 can perform milling operations during rotation and lowering to clean impurities from the inner wall of the wellbore, and it has a long service life. It should also be noted that the shape of the sawtooth teeth 132 is not required here; any sawtooth teeth 132 with milling functionality is acceptable.
[0059] The present invention also provides a method for using the milling and fishing device, the method being implemented based on the above-mentioned milling and fishing device, and comprising the following steps in sequence:
[0060] S1: Select a suitable milling and retrieval device based on the inner wall of the well and the condition of the fallen objects, and connect and secure it to the tubing via the third female thread 112 and the male thread on the tubing to form a tubing string; S2: Lower the milling and retrieval device to a position 3 meters above the obstruction point at the standard tubing string speed; S3: Connect the backwashing pipeline and turn on the circulation pump on the cement truck to circulate and wash the well; S4: While circulating and washing the well, rotate and lower the tubing string to perform milling operations, cleaning impurities from the inner wall of the well. The washing fluid carries the impurities upward through the inner cavity of the milling section 13, the central channel of the third wire bundle group (from top to bottom, the wire bundle group 2 is divided into the first wire bundle group, the second wire bundle group, and the third wire bundle group), the central channel of the second wire bundle group, the central channel of the first wire bundle group, the retrieval chamber, the inner cavity of the connecting section 11, and the inner cavity of the tubing, returning to the surface. Large impurities that cannot be carried away remain in the retrieval chamber. S5: When the casing is milled to a depth of 5 meters from the top of the cement plug, increase the flow rate of the circulation pump to allow any movable debris on the cement plug to rise with the washing fluid; S6: While circulating the washing fluid, continue to rotate and lower the tubing string, paying attention to changes in the suspended weight. After reaching the location of the fallen object, perform the casing milling retrieval operation; S7: When the casing milling depth reaches 1.5 meters, stop lowering the tubing string. The first retrieval operation is complete. At this point, the small pieces of debris that cannot be brought to the surface by the washing fluid remain in the retrieval cavity due to the obstruction of the first, second, and third wire bundle groups. The second wire bundle group holds small pieces of pipe or rod debris; S8: Raise the tubing string 2 meters, rotate and lower the tubing string again to the first retrieval position to complete the second retrieval operation. The casing milling retrieval is complete; S9: Stop the pump after one cycle of washing the well and remove the backwashing pipeline; S10: Raise the casing milling retrieval device at a limited speed, and the retrieval process should not be sudden or abrupt. During the entire process of milling and retrieval, the pressure applied should not exceed 3000 kg, and the well washing cycle should not be stopped for more than 5 minutes.
[0061] In the above-described milling and retrieval device, milling is performed simultaneously with circulation. The YD alloy block at the bottom of the milling section 13 cuts off impurities from the well wall, which are then returned to the surface with the washing fluid. During milling and retrieval, small objects falling into the well are pushed upwards to the retrieval chamber by the high-pressure washing fluid. They are prevented from falling back into the well by the platforms formed by the first, second, and third wire bundle groups. Small objects such as pipes and rods are caught by the wire bundles when passing through the second wire bundle group, thus achieving retrieval. Therefore, it can be seen that using this milling and retrieval device, both milling and retrieval operations can be completed in a single tubing run, reducing construction steps and saving construction costs.
[0062] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and not to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features; and these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention.
Claims
1. A milling and fishing device, characterized in that, include: Working cylinder (1) and filament bundle (2); The working cylinder (1) is open at both ends and includes a fixedly connected connecting section (11), a retrieval section (12), and a milling section (13) in sequence. The inner diameter of the connecting section (11) is smaller than the inner diameter of the retrieval section (12). The filament bundle group (2) is composed of multiple clusters of filament bundles distributed circumferentially along the retrieval section (12). One end of each cluster of filament bundles is fixed to the side wall of the retrieval section (12), and the other end extends in a direction close to the axis of the retrieval section (12) and is distributed in a fan shape.
2. The milling and fishing device according to claim 1, characterized in that, The filament bundle (2) is provided in multiple groups; Multiple sets of the wire bundles (2) are spaced apart along the axial direction of the milling section (13); In the circumferential direction of the milling section (13), the clusters of the multiple sets of filament bundles (2) are interleaved.
3. The milling and fishing device according to claim 2, characterized in that, The filament bundle (2) shall have at least three groups; The other end of each cluster of filaments in the middle filament bundle group (2) extends toward the connecting section (11), and the other end of each cluster of filaments in the remaining filament bundle groups (2) extends in a direction perpendicular to the axial direction of the milling section (13).
4. The milling and fishing device according to any one of claims 1 to 3, characterized in that, The filament bundle is made of steel wire.
5. The milling and fishing device according to claim 1, characterized in that, One end of the salvage section (12) is provided with a first female thread (121), which is a tubular thread; The connecting section (11) is provided with a first male thread (111) that is adapted to the first female thread (121), and is connected to the salvage section (12) through the first male thread (111) and the first female thread (121).
6. The milling and fishing device according to claim 1, characterized in that, The end of the salvage section (12) away from the connecting section (11) is provided with a second female thread (122), and the second female thread (122) is a tubular thread; The milling section (13) is provided with a second male thread (131) that is compatible with the second female thread (122), and is connected to the salvage section (12) through the second male thread (131) and the second female thread (122).
7. The milling and fishing device according to claim 1, characterized in that, The free end of the connecting section (11) is provided with a third female thread (112) for connection with the oil pipe; Except for the free end, the diameter of the connecting section (11) is not greater than the inner diameter of the oil pipe to which it is connected.
8. The milling and fishing device according to claim 1, characterized in that, The end face of the milling section (13) away from the salvage section (12) is a plane, and a YD alloy block is welded on the plane; Alternatively, the end face of the milling section (13) away from the retrieval section (12) is provided with serrated teeth (132), the serrated teeth (132) extend circumferentially along the milling section (13), and a YD alloy block is welded on it.
9. A method of using a milling and fishing device, characterized in that, The milling and fishing device according to any one of claims 1 to 8 comprises the following steps: S1: Connect the milling and retrieval device to the oil pipe to form a tubing string. Then, lower the milling and retrieval device to a position 3 meters above the obstruction point at the standard tubing string speed. S2: Connect the backwash well pipeline, turn on the circulation pump on the cement truck, and circulate the well for washing. S3: While circulating the well, rotate and lower the tubing string, and increase the circulation pump discharge when the casing is milled to 5 meters from the top of the cement plug. S4: While circulating and washing the well, continue to rotate and lower the tubing string, and pay attention to changes in the suspended weight. After reaching the location of the fallen object, carry out milling and retrieval operations. S5: Stop lowering the tubing column when the milling depth reaches 1.5 meters; S6: Raise the tubing 2 meters, rotate and lower the tubing back to the first retrieval position to complete the second retrieval operation; S7: Stop the pump and remove the backwash pipeline one week after well washing; S8: Limit the speed of lifting out the milling and retrieval device, and the lifting process must not involve sudden stops or releases.
10. The method of using the milling and fishing device according to claim 9, characterized in that, During the entire process of milling and retrieval, the pressure applied should not exceed 3000 kg, and the well washing cycle should not be stopped for more than 5 minutes.