Milling shoe with staggered center

Abstract

The utility model discloses a milling shoe with a staggered center, which is used for cleaning obstacles in a well, the milling shoe with the staggered center comprises a connector, a milling shoe body, a cutter body and a cutter head, a connecting thread is arranged in the connector, the connector is in detachable threaded connection with an external drilling tool, and the milling shoe body and the cutter body are both of a cylindrical structure and are coaxially arranged; one end of the milling shoe body is fixedly connected to one end of the connector, and one end of the cutter body is fixedly connected to the other end of the milling shoe body; the cutter head is disc-like, the end face of one side of the cutter head is fixedly connected with the cutter body, and the center of the cutter head is concentric with the axis of the milling shoe body; a plurality of cutting edges are circumferentially arranged on the periphery of the tool bit at intervals and penetrate through the end faces of the two sides of the tool bit, a plurality of cutting grooves are correspondingly formed in the end face of one side of the tool bit, one ends of the cutting grooves are communicated, and the other ends of the cutting grooves extend to the cutting edges; the communicating position of the cutting groove is a cutting center which is far away from the center of the tool bit. The milling device is simple in structure, and the milling stability and the milling speed are improved.

Description

Technical Field

[0001] The utility model relates to a downhole complex treatment milling tool, in particular to a central misalignment mill shoe. Background Art

[0002] A mill shoe is used to mill the downhole metal debris and trim the fish head, and sometimes it is also used to mill the shorter stuck drill collars and drill pipes. A flat-bottom mill shoe is a tool that uses the YD alloy or wear-resistant material on the bottom surface to grind the downhole debris. Such as grinding bits, cones, drift gauges, slips teeth, wash pipes, drill tool connectors, deep well pump accessories, packers, water distributors, and longer drill tools and other debris.

[0003] When the oilfield enters the middle and late stages of development, adjusting the well path has become an effective means to exploit the remaining reservoirs, and the low-yield and low-efficiency old wellbores have also become important objects for sidetracking. During the process of treating low-efficiency wells and old well casings, due to the limitations of conventional milling tools, the milling speed is slow, and the rotational speed of the center of the mill shoe is zero, resulting in a slow milling speed and low cleaning efficiency.

[0004] Therefore, how to provide a central misalignment mill shoe that solves the problem of zero rotational speed at the center and the mill shoe top core and has high milling efficiency is an urgent problem to be solved by those skilled in the art. Summary of the Utility Model

[0005] In view of this, the utility model provides a central misalignment mill shoe, which can reduce the phenomenon of zero rotational speed at the center of the mill shoe and the mill shoe top core and improve the milling efficiency.

[0006] To achieve the above purpose, the utility model adopts the following technical scheme: A central misalignment mill shoe for cleaning obstacles in a well path, including a connector, a mill shoe body, a cutter body and a cutter head. The connector has a through hole and the inner wall of the through hole is provided with connecting threads. The connector is detachably threadedly connected with an external drill tool. The mill shoe body and the cutter body are both cylindrical structures and are coaxially arranged. One end of the mill shoe body is fixedly connected to one end of the connector, and one end of the cutter body is fixedly connected to the other end of the mill shoe body. The cutter head is in the shape of a disc-like, and one side end face thereof is fixedly connected to the cutter body, and the center of the cutter head is concentric with the axis of the mill shoe body. A plurality of cutting edges are circumferentially spaced around the periphery of the cutter head, and the cutting edges penetrate through both side end faces of the cutter head. A plurality of cutting grooves are correspondingly arranged on one side end face of the cutter head, and the plurality of cutting grooves are arranged in a radial pattern around the circumference. One end of the cutting grooves is interconnected, and the other ends respectively extend to the cutting edges. The interconnected position of the cutting grooves is the cutting center, and the cutting center is away from the center of the cutter head.

[0007] Advantages of the utility model: A connector, a mill shoe body, cutter heads and cutter bodies are provided. The connector is connected to a drill tool, which provides rotational power and downward pressure for this device, drives the cutter body to rotate. A plurality of cutting edges are circumferentially arranged on the outer periphery of the cutter body. A plurality of cutting grooves are arranged on one end face of the cutter body. One end of the cutting groove is connected, and the other ends respectively extend to the positions of the cutting edges. The connected position of the cutting grooves is the cutting center, and the cutting center is far from the center of the cutter head, so that the center of the mill shoe body is misaligned with the cutting center, reducing the phenomenon that the rotation speed of the center of the mill shoe is zero and the mill shoe jamming at the center, improving the milling efficiency. Moreover, the structure of the utility model is simple, easy to use, and convenient for popularization and application.

[0008] Preferably, the outer diameter of the mill shoe body is 3 - 6 mm smaller than the inner diameter of the wellbore.

[0009] Preferably, the outer diameter of the cutter body is larger than that of the mill shoe body, and a plurality of chip removal grooves are circumferentially arranged at intervals on the outer periphery of the cutter body, and the groove direction of the chip removal groove is parallel to the axis of the cutter body.

[0010] Preferably, one end face of the cutter head is a grinding surface, and YD type alloy electrodes and grinding teeth are welded on both the grinding surface and the outer peripheral side surface of the cutter head.

[0011] Preferably, the connector, the mill shoe body and the cutter body are integrally and fixedly formed.

[0012] Preferably, the cross-sectional shape of the cutting edge is a right angle; cutting teeth are formed at the positions of the cutting edges on the circumferential side of the cutter head.

[0013] Preferably, a water passage is arranged along the axial direction inside the mill shoe body, and a plurality of water holes are arranged on the cutter head; a plurality of branch pipes are arranged inside the cutter body, one end of each branch pipe is connected to the water passage, and the other ends respectively extend and communicate with the water holes correspondingly. Description of the drawings

[0014] Figure 1 It is a schematic diagram of the overall structure of the center misaligned mill shoe of the utility model;

[0015] Figure 2 It is a schematic diagram of the A cross-section of the center misaligned mill shoe of the utility model.

[0016] 1 Connector, 2 Mill shoe body, 3 Cutter body, 4 Cutter head, 5 Cutting groove, 6 Cutting edge, 7 Connection thread, 8 Cutting tooth, 9 Water passage, 10 Water hole, 11 Branch pipe, 12 Chip removal groove, 13 Cutting center, 14 Cutter head center. Detailed implementation manners

[0017] Next, the technical solutions in the embodiments of the present utility model will be clearly and completely described in conjunction with the accompanying drawings in the embodiments of the present utility model. Obviously, the described embodiments are only a part of the embodiments of the present utility model, rather than all the embodiments. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present utility model without creative efforts shall fall within the protection scope of the present utility model.

[0018] Referring to the attached Figures 1 to 2 drawing of the present utility model, according to the center-offset mill shoe in the embodiment of the present utility model, which is used to clean the obstacles in the wellbore, including a connection head 1, a mill shoe body 2, a cutter body 3 and a cutter head 4. The connection head 1 has a through hole and the inner wall of the through hole is provided with a connection thread 7. The connection head 1 is detachably connected to an external drill string. Both the mill shoe body 2 and the cutter body 3 are cylindrical structures; one end of the mill shoe body 2 is fixedly connected to one end of the connection head 1, and one end of the cutter body 3 is fixedly connected to the other end of the mill shoe body 2; the cutter head 4 is disk-like, and one side end face thereof is fixedly connected to the cutter body 3. The center of the cutter head 4 is concentric with the axis of the mill shoe body 2; a plurality of cutting edges 6 are circumferentially spaced around the periphery of the cutter head 4, and the cutting edges 6 penetrate through both side end faces of the cutter head 4. A plurality of cutting grooves 5 are provided on one side end face of the cutter head 4, and the plurality of cutting grooves 5 are arranged in a radially radiating pattern around the circumference. One end of the cutting grooves 5 is interconnected, and the other ends respectively extend to the cutting edges 6; the interconnected position of the cutting grooves 5 is the cutting center, and the cutting center 13 is away from the cutter head center 14.

[0019] In some specific embodiments, the outer diameter of the mill shoe body 2 is 3 - 6 mm less than the inner diameter of the wellbore.

[0020] It is convenient for the iron filings to effectively return during the milling process, preventing sticking of the drill string. Use a lathe to remove the uneven parts, so that the center of the outer circle of the cutter head is concentric with the center of the drill string, ensuring the flatness of the outer peripheral side of the cutter head and the safety of the construction.

[0021] In some other specific embodiments, one side end face of the cutter head 4 is a grinding surface, and both the grinding surface and the outer peripheral side surface of the cutter head 4 are welded with YD-type alloy electrodes and grinding teeth. The milling durability of the cutter head is enhanced, and the service life of the mill shoe is prolonged.

[0022] The specific grinding teeth are octagonal pyramid structures, and their taper is 1:1.5. The grinding effect of the mill shoe is strengthened.

[0023] In some other specific embodiments, the connection head, the mill shoe body and the cutter body are integrally and fixedly formed, avoiding the instability of the intermediate connection thread. It is made by one-time turning and milling of an integral casting, improving the reliability and safety of the overall device.

[0024] In some other specific embodiments, the cross-sectional shape of the cutting edge 6 is a right angle, and cutting teeth 8 are formed at the cutting edge positions on the circumferential side of the cutter head 4, providing cutting conditions for the dredging and cleaning of the pipeline.

[0025] In some other embodiments, a water passage 9 is axially provided in the mill shoe body 2, and a plurality of water eyes 10 are provided on the cutter head 4; a plurality of branch pipes 11 are provided in the cutter body 3, one ends of the branch pipes 11 are communicated with the water passage, and the other ends respectively extend and communicate with the water eyes 10 correspondingly. During the working process of the mill shoe, cooling water can be passed through to cool the mill shoe, prevent high temperature and extend the service life.

[0026] The specific operation steps of the cooperation between the utility model and an external drill tool are as follows:

[0027] The central misalignment mill shoe of the utility model is connected with the drill tool through the upper end thread of the connector 1. Before lowering into the well, the dimensions of each part are accurately measured. The pipe string is lowered to the predetermined depth and slowly lowered. After the cutter head 4 touches the upper end of the fish head, the changes of the hook load indicator and the pump pressure gauge are observed. The rotary table is slowly started, and the changes of the hook load and the torque are observed. When the milling is in place, a small drilling pressure milling operation is adopted, and the milling parameters are appropriately adjusted in combination with the comprehensive milling record to make the central misalignment mill shoe of the utility model achieve the best milling effect. If there is a state of no penetration for a long time, consider pulling out the drill to check the mill shoe. The utility model can give full play to the role of the cutter head, improve the overall milling efficiency and provide powerful conditions for subsequent adjustment and sidetracking.

[0028] For the devices and usage methods disclosed in the embodiments, since they correspond to the methods disclosed in the embodiments, the description is relatively simple. For the relevant parts, reference can be made to the description in the method part.

[0029] The above description of the disclosed embodiments enables those skilled in the art to implement or use the utility model. Various modifications to these embodiments will be apparent to those skilled in the art. The general principles defined herein can be implemented in other embodiments without departing from the spirit or scope of the utility model. Therefore, the utility model will not be limited to the embodiments shown herein, but will be accorded the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. The center offset grinding shoe is used to clear obstacles in the well, characterized by: The invention comprises a connecting head (1), a grinding shoe body (2), a cutter body (3) and a cutter head (4); the connecting head (1) has a through hole and the inner wall of the through hole is provided with a connecting thread (7); the connecting head (1) is detachably threadedly connected to an external drilling tool; the grinding shoe body (2) and the cutter body (3) are both cylindrical structures and are coaxially arranged; one end of the grinding shoe body (2) is fixedly connected to one end of the connecting head (1), and one end of the cutter body (3) is fixedly connected to the other end of the grinding shoe body (2); the cutter head (4) is disc-shaped, and one end surface of the cutter head (4) is fixedly connected to the cutter body (3); The cutter head (4) is fixedly connected, the center of the cutter head (4) is concentric with the axis of the grinding shoe body (2); a plurality of cutting edges (6) are arranged at intervals on the periphery of the cutter head (4), the cutting edges (6) penetrate the two side end faces of the cutter head (4); a plurality of cutting grooves (5) are arranged on one side end face of the cutter head (4), the plurality of cutting grooves (5) are arranged in a radial pattern around the periphery, one end of the cutting grooves (5) are connected to each other, and the other end respectively extends to the cutting edges (6); the connection position of the cutting grooves (5) is the cutting center (13), and the cutting center is far away from the cutter head center (14).

2. The center offset grinding shoe according to claim 1, characterized in that: The outer diameter of the grinding shoe body (2) is 3-6 mm smaller than the inner diameter of the well.

3. The center offset grinding shoe according to claim 1, characterized in that: The outer diameter of the cutter body (3) is greater than the outer diameter of the grinding shoe body (2), and a plurality of chip removal grooves (12) are provided at intervals in the circumferential direction of the outer periphery of the cutter body (3), and the groove direction of the chip removal grooves (12) is parallel to the axis of the cutter body (3).

4. The center offset grinding shoe according to claim 1, characterized in that: One end face of the cutter head (4) is a grinding surface, and the grinding surface and the outer peripheral side surface of the cutter head (4) are welded with a YD-type alloy welding rod and a plurality of grinding teeth.

5. The center offset grinding shoe according to claim 1, characterized in that: The connecting head (1), the grinding shoe body (2) and the cutter body (3) are integrally fixed and formed.

6. The center offset grinding shoe according to claim 1, characterized in that: The cross-sectional shape of the blade (6) is a right angle; and cutting teeth (8) are formed at the blade on the peripheral side of the cutter head (4).

7. The center offset grinding shoe according to claim 1, characterized in that: A water passage (9) is provided in the grinding shoe body (2) along its axial direction, and a plurality of water holes (10) are provided on the cutter head (4); a plurality of branch pipes (11) are provided in the cutter body (3), one end of each branch pipe (11) is connected to the water passage, and the other end thereof is extended to be connected to the water holes (10) respectively.

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