A milling fishing device

Abstract

The application relates to the field of downhole fishing devices, and discloses a milling and fishing device, which comprises a bottom cylinder, a top cylinder arranged above the bottom cylinder, and an intermediate cylinder arranged between the bottom cylinder and the top cylinder. In the application, the bottom cylinder, the top cylinder, the intermediate cylinder and a connecting head are sequentially screwed, a plurality of milling teeth are fixed on the bottom of the bottom cylinder through a first annular plate, a collecting assembly is arranged in the bottom cylinder, and a conical cylinder is arranged in the intermediate cylinder, so that the milling and fishing are integrated, the milling teeth mill the fallen objects into fragments, the liquid and the fragments can pass through a material passing cavity and push the elastic sheets apart, thereby entering the top of a collecting barrel, the larger fragments can fall into the collecting barrel, the smaller fragments can pass through the conical cylinder and gather in a collecting groove, and the elastic sheets are reset to shield the material passing cavity when the work is stopped, so that the fragments are prevented from flowing back, the milling of the fallen objects is realized, the fragments after milling can be collected and fished, and the fishing efficiency is greatly improved.

Description

Technical Field

[0001] This invention relates to the field of downhole fishing devices, and in particular to a milling fishing device. Background Technology

[0002] In oil extraction, when packers cannot be released and pulled up, corroded tubing cannot be pulled up, or other debris cannot be directly retrieved, it is usually necessary to mill the debris before retrieval. Milling generates a large amount of lumps of iron and alloy. Ideally, these lumps would fall directly to the bottom of the well. However, in practice, some lumps become stuck at the milling point, causing the milling gear to repeatedly mill the debris, damaging the gears and reducing efficiency. Existing techniques typically involve lowering a milling tool into the well to mill the debris, then pulling it up, and finally lowering a retrieval tool – a cumbersome and time-consuming process. Furthermore, existing retrieval tools are mostly only suitable for large items like tubing, packers, and bridge plugs, and cannot retrieve milled debris. Therefore, we propose a milling and retrieval device to address these problems. Summary of the Invention

[0003] The purpose of this invention is to provide a milling and retrieval device to solve the problems mentioned in the background art, such as the inability to perform milling and retrieval simultaneously and the inability to retrieve milled block objects.

[0004] To achieve the above objectives, the present invention provides the following technical solution:

[0005] A milling and fishing device includes a bottom cylinder, a top cylinder above the bottom cylinder, an intermediate cylinder between the top cylinder and the bottom cylinder, the top cylinder being connected to the bottom cylinder through the intermediate cylinder, and a connector being provided above the top cylinder.

[0006] A first annular plate is fixedly connected to the lower surface of the bottom cylinder. A plurality of grinding teeth are fixedly connected to the end of the first annular plate away from the bottom cylinder, and the plurality of grinding teeth are distributed in a ring array about the central axis of the first annular plate.

[0007] An anti-clogging component is provided inside the lower end of the bottom cylinder, a collecting component is provided inside the upper end of the bottom cylinder, and a conical cylinder is provided inside the middle cylinder.

[0008] In a further embodiment, the upper inner wall of the bottom cylinder, the upper inner wall of the top cylinder, and the lower inner wall of the top cylinder are all provided with internal threads, and the lower outer wall of the connector, the upper outer wall of the intermediate cylinder, and the lower outer wall of the middle cylinder are all provided with external threads that are compatible with the internal threads.

[0009] In a further embodiment, the upper and lower ends of the intermediate cylinder are threaded to the lower end of the top cylinder and the upper end of the bottom cylinder, respectively, and the lower end of the connector is threaded to the upper end of the top cylinder.

[0010] In a further embodiment, the inner diameters of the bottom cylinder, the intermediate cylinder, the top cylinder, and the connector are all equal.

[0011] In a further embodiment, the anti-blocking component includes a second annular plate, the outer wall of which is fixedly connected to the inner wall of the bottom cylinder, and a plurality of uniformly distributed through holes are provided in the middle of the second annular plate.

[0012] In a further embodiment, the middle part of the second annular plate is rotatably connected to a circular plate via a bearing. The middle part of the circular plate has a circular hole, and a positioning rod is slidably connected inside the circular hole. The bottom end of the positioning rod is located below the circular plate and is fixedly connected to a rubber pad. The top end of the positioning rod is located above the circular plate and is fixedly connected to a limiting plate. A spring is sleeved on the outside of the top end of the positioning rod. The two ends of the spring are fixedly connected to the limiting plate and the circular plate, respectively. The rubber pad is located below the grinding teeth.

[0013] In a further embodiment, a fixing ring is fitted around the outside of the positioning rod and below the circular plate. Connecting rods are symmetrically fixed to both sides of the fixing ring, and the connecting rods do not contact the bottom cylinder. A scraper is fixedly connected to the side of the connecting rod near the second annular plate.

[0014] In a further embodiment, the collection assembly includes a collection bucket, with a plurality of fixing rods fixedly connected to the lower end of the collection bucket. The ends of the fixing rods away from the collection bucket are fixedly connected to the inner wall of the bottom cylinder. A third annular plate is fixedly connected to the top opening of the collection bucket. A plurality of elastic sheets are fixedly connected to the end of the third annular plate away from the collection bucket. The plurality of elastic sheets are arranged in a circular array about the central axis of the third annular plate, with gaps between adjacent elastic sheets. The plurality of elastic sheets together form a funnel shape, and the ends of the elastic sheets away from the third annular plate are in contact with the inner wall of the bottom cylinder.

[0015] In a further embodiment, the diameter of the collecting bucket is smaller than the inner diameter of the bottom cylinder, a material passage cavity is formed between the outer wall of the collecting bucket and the inner wall of the bottom cylinder, and a conical block is fixedly connected to the bottom of the collecting bucket, with the apex of the conical block facing the limiting plate.

[0016] In a further embodiment, a fourth annular plate is coaxially fixedly connected to the large end of the conical cylinder. The outer wall of the fourth annular plate is fixedly connected to the inner wall of the intermediate cylinder. The inner diameter of the fourth annular plate is equal to the inner diameter of the large end of the conical cylinder. The outer diameter of the large end of the conical cylinder is smaller than the inner diameter of the intermediate cylinder. The outer wall of the conical cylinder, the upper surface of the fourth annular plate, and the inner wall of the intermediate cylinder together form a collection trough.

[0017] Compared with the prior art, the beneficial effects of the present invention are:

[0018] In this invention, a bottom cylinder, a top cylinder, an intermediate cylinder, and a connector are sequentially threaded together. Multiple grinding teeth are fixed at the bottom of the bottom cylinder by a first annular plate. A collection component is installed inside the bottom cylinder, and a conical cylinder is installed inside the intermediate cylinder, forming a grinding and retrieval system. The grinding teeth grind the falling object into fragments. Liquid and fragments can pass through the material passage chamber and push open the elastic plate, thus entering the upper part of the collection tank. Larger fragments can fall into the collection tank, while smaller fragments can pass through the conical cylinder and gather in the collection trough. When the operation stops, the elastic plate will reset and block the material passage chamber to prevent fragments from flowing back. This not only achieves grinding of the falling object but also collection and retrieval of the ground fragments, greatly improving retrieval efficiency.

[0019] In this invention, an anti-clogging component is incorporated. Before the milling and retrieval device stops descending, the rubber pad contacts the object first. When the grinding teeth contact the object, the rubber pad abuts against the object, and the second annular plate contacts the scraper. This prevents the grinding teeth from shifting during milling. Simultaneously, during the milling and retrieval process, the bottom cylinder drives multiple grinding teeth to rotate via the first annular plate and mills the object. At the same time, under the action of the bearing, the bottom cylinder drives the second annular plate to rotate around the circular plate, so that the second annular plate can move relative to the scraper. The scraper can cyclically scrape the lower surface of the second annular plate, preventing debris from accumulating at the through hole and causing blockage. Attached Figure Description

[0020] Figure 1 A three-dimensional structural schematic diagram of a milling and fishing device;

[0021] Figure 2 This is a schematic cross-sectional view of the structure in this invention;

[0022] Figure 3 For the present invention Figure 1 Enlarged structural diagram at point A in the middle;

[0023] Figure 4 This is a three-dimensional structural diagram of the anti-clogging component in this invention;

[0024] Figure 5 This is a schematic diagram of the three-dimensional structure of the collection component in this invention.

[0025] In the diagram: 1. Bottom cylinder; 101. First annular plate; 102. Grinding teeth; 2. Top cylinder; 3. Intermediate cylinder; 4. Connector; 5. Anti-blocking component; 501. Second annular plate; 502. Circular plate; 503. Through hole; 504. Positioning rod; 505. Rubber pad; 506. Limiting plate; 507. Spring; 508. Fixing ring; 509. Connecting rod; 510. Scraper; 6. Collection component; 601. Collection bucket; 602. Fixing rod; 603. Third annular plate; 604. Elastic sheet; 7. Conical cylinder. Detailed Implementation

[0026] 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. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0027] Example 1

[0028] Please see Figures 1-5 In this embodiment of the invention, a milling and fishing device includes a bottom cylinder 1, a top cylinder 2 above the bottom cylinder 1, an intermediate cylinder 3 between the top cylinder 2 and the bottom cylinder 1, the top cylinder 2 being connected to the bottom cylinder 1 through the intermediate cylinder 3, and a connector 4 being provided above the top cylinder 2.

[0029] A first annular plate 101 is fixedly connected to the lower surface of the bottom cylinder 1. A plurality of grinding teeth 102 are fixedly connected to the end of the first annular plate 101 away from the bottom cylinder 1, and the plurality of grinding teeth 102 are arranged in a ring array about the central axis of the first annular plate 101. With this configuration, when the drive device connected to the pipe column is started, the drive device drives the pipe column and the connector 4 to rotate. The connector 4 drives the top cylinder 2, the intermediate cylinder 3 and the bottom cylinder 1 below it to rotate. The bottom cylinder 1 drives the plurality of grinding teeth 102 to rotate through the first annular plate 101 and grind the falling object.

[0030] An anti-blocking component 5 is installed inside the lower end of the bottom cylinder 1, a collecting component 6 is installed inside the upper end of the bottom cylinder 1, and a conical cylinder 7 is installed inside the middle cylinder 3. This anti-blocking component 5 can prevent the milling debris from accumulating and causing blockage, and the collecting component 6 can collect larger debris.

[0031] Specifically, the upper inner wall of the bottom cylinder 1, the upper inner wall and the lower inner wall of the top cylinder 2 are all provided with internal threads, and the lower outer wall of the connector 4, the upper outer wall and the lower outer wall of the intermediate cylinder 3 are all provided with external threads that are compatible with the internal threads; the upper and lower ends of the intermediate cylinder 3 are threaded to the lower end of the top cylinder 2 and the upper end of the bottom cylinder 1, respectively, and the lower end of the connector 4 is threaded to the upper end of the top cylinder 2; this arrangement facilitates the spiral assembly of the bottom cylinder 1, the top cylinder 2, the intermediate cylinder 3 and the connector 4.

[0032] The inner diameters of the bottom cylinder 1, the middle cylinder 3, the top cylinder 2, and the connector 4 are all equal; this arrangement makes the inner walls of the bottom cylinder 1, the top cylinder 2, the middle cylinder 3, and the connector 4 flush, facilitating the movement of liquids and fragments within them.

[0033] Furthermore, the anti-clogging component 5 includes a second annular plate 501, the outer wall of which is fixedly connected to the inner wall of the bottom cylinder 1, and a plurality of evenly distributed through holes 503 are provided in the middle of the second annular plate 501; this arrangement allows fragments to enter the bottom cylinder 1 through the through holes 503, while the second annular plate 501 can cooperate with the scraper 510 to prevent clogging.

[0034] Furthermore, the middle part of the second annular plate 501 is rotatably connected to the circular plate 502 via a bearing. The circular plate 502 has a circular hole in its middle, and a positioning rod 504 is slidably connected inside the circular hole. The bottom end of the positioning rod 504 is located below the circular plate 502 and is fixedly connected to a rubber pad 505. The top end of the positioning rod 504 is located above the circular plate 502 and is fixedly connected to a limit plate 506. A spring 507 is sleeved on the outside of the top end of the positioning rod 504. The two ends of the spring 507 are fixedly connected to the limit plate 506 and the circular plate, respectively. 502 is fixedly connected, and the rubber pad 505 is located below the grinding teeth 102. With this arrangement, before the milling and retrieval device stops descending, the rubber pad 505 will contact the falling object first. When the milling and retrieval device continues to descend, the bottom cylinder 1 drives the circular plate 502 to slide down along the positioning rod 504 through the second annular plate 501 and the bearing. When the circular plate 502 slides down, it can stretch the spring 507. The spring 507 is stressed and transmits this force to the positioning rod 504 through the limiting plate 506, so that the rubber pad 505 comes into contact with the falling object.

[0035] Furthermore, a fixing ring 508 is fitted around the outside of the positioning rod 504 and below the circular plate 502. Connecting rods 509 are symmetrically fixed to both sides of the fixing ring 508, and the connecting rods 509 do not contact the bottom cylinder 1. A scraper 510 is fixedly connected to the side of the connecting rod 509 near the second annular plate 501. When the drive device drives the device to rotate, the bottom cylinder 1 drives the second annular plate 501 to rotate. Under the action of the bearing, the circular plate 502 does not move when the second annular plate 501 rotates, so that the second annular plate 501 can contact the scraper 510 when it rotates. The scraper 510 can cyclically scrape the lower surface of the second annular plate 501 to avoid clogging of the through hole 503, thereby facilitating the collection component 6 to collect the fragments.

[0036] Example 2

[0037] Please see Figure 2 and Figure 5 The difference from Example 1 is:

[0038] Specifically, the collection component 6 includes a collection bucket 601. Multiple fixing rods 602 are fixedly connected to the lower end of the collection bucket 601. The ends of the fixing rods 602 away from the collection bucket 601 are fixedly connected to the inner wall of the bottom cylinder 1. A third annular plate 603 is fixedly connected to the top opening of the collection bucket 601. Multiple elastic plates 604 are fixedly connected to the end of the third annular plate 603 away from the collection bucket 601. The multiple elastic plates 604 are arranged in a circular array about the central axis of the third annular plate 603, with gaps between adjacent elastic plates 604. The multiple elastic plates 604 together form a funnel shape. The ends of the elastic plates 604 away from the third annular plate 603 are connected to the bottom cylinder 1. The inner wall of cylinder 1 is in contact; the diameter of collecting bucket 601 is smaller than the inner diameter of bottom cylinder 1, and a material passage cavity is formed between the outer wall of collecting bucket 601 and the inner wall of bottom cylinder 1. A conical block is fixedly connected to the bottom of collecting bucket 601, and the apex of the conical block is directly opposite the limiting plate 506. With this setting, the liquid and fragments entering the material passage cavity will continue to move upward and push open the elastic plate 604, causing the top of the elastic plate 604 to contract inward, so that the fragments enter the lower end of the intermediate cylinder 3 through the upper end of bottom cylinder 1. At the same time, after the larger fragments enter the lower end of the intermediate cylinder 3, they will contact the bottom of the fourth annular plate, and then the larger fragments will move downward and fall into collecting bucket 601.

[0039] Furthermore, a fourth annular plate is coaxially fixedly connected to the large end of the conical cylinder 7. The outer wall of the fourth annular plate is fixedly connected to the inner wall of the intermediate cylinder 3. The inner diameter of the fourth annular plate is equal to the inner diameter of the large end of the conical cylinder 7. The outer diameter of the large end of the conical cylinder 7 is smaller than the inner diameter of the intermediate cylinder 3. The outer wall of the conical cylinder 7, the upper surface of the fourth annular plate, and the inner wall of the intermediate cylinder 3 together form a collection trough. With this arrangement, smaller fragments will pass through the conical cylinder 7 with the liquid flow. Since the top opening of the conical cylinder 7 is at the small end, the liquid enters the top cylinder 2 through this point, which increases the backflow speed, so that smaller fragments will not flow back but will only accumulate in the collection trough.

[0040] The working principle of this invention is as follows: When retrieving a fallen object, the connector 4 is first connected to the tubing string, and the milling and retrieval device is lowered into the well by the tubing string. Before the milling and retrieval device stops descending, the rubber pad 505 will contact the fallen object first. As the milling and retrieval device continues to descend, the bottom cylinder 1 drives the circular plate 502 to slide down along the positioning rod 504 through the second annular plate 501 and the bearing. When the circular plate 502 slides down, it can stretch the spring 507. The spring 507 is subjected to force and transmits this force to the positioning rod 504 through the limiting plate 506, so that the rubber pad 505 comes into contact with the fallen object.

[0041] When the milling and retrieval device stops descending, the grinding teeth 102 contact the object in the well, and the lower surface of the second annular plate 501 contacts the top of the scraper 510. Then, the drive device connected to the tubing string is started, and the drive device drives the tubing string and connector 4 to rotate. The connector 4 drives the top cylinder 2, intermediate cylinder 3 and bottom cylinder 1 below it to rotate. The bottom cylinder 1 drives multiple grinding teeth 102 to rotate through the first annular plate 101 and mills the object. At the same time, the bottom cylinder 1 drives the second annular plate 501 to rotate. Under the action of the bearing, the circular plate 502 does not move when the second annular plate 501 rotates, so that the second annular plate 501 can contact the scraper 510 when it rotates. The scraper 510 can circulate and scrape the lower surface of the second annular plate 501.

[0042] Simultaneously, when the drive device is started, liquid is injected into the annular cavity between the tubing and the casing. During the continuous injection process, the fragments formed after the falling object is milled will enter the bottom cylinder 1 from bottom to top with the liquid in the annular cavity. After entering the bottom of the bottom cylinder 1, the fragments will move upward through the through hole 503 on the second annular plate 501. Under the scraping of the scraper 510, the fragments can be prevented from accumulating at the through hole 503 and causing the through hole 503 to be blocked. At the same time, it is convenient for the collection component 6 to collect them.

[0043] As the fragments pass through the through-hole 503 and move upwards, some fragments will directly enter the material passage chamber, while others will contact the arc-shaped surface of the cone block and enter the material passage chamber under the guidance of the cone block. The liquid and fragments entering the material passage chamber will continue to move upwards, pushing open the elastic plate 604 and causing the top of the elastic plate 604 to contract inwards. This allows the fragments to pass through the upper end of the bottom cylinder 1 and enter the lower end of the intermediate cylinder 3. At the same time, larger fragments, after entering the lower end of the intermediate cylinder 3, will contact the bottom of the fourth annular plate, and then the larger fragments will move downwards. The material moves and falls into the collection bucket 601; at the same time, smaller fragments will pass through the conical cylinder 7 with the flow of liquid. Since the top opening of the conical cylinder 7 is at the small end, the liquid enters the top cylinder 2 through this point, which increases the backflow speed, so that the smaller fragments will not flow back, but will only gather in the collection tank. Then the drive equipment is turned off and no more liquid is injected into the annulus. At this time, the elastic sheet 604 loses the pressure of the liquid and fragments and resets, thereby blocking the upper end of the material passage chamber. In this way, the fragments will not flow back downwards. Finally, the milling and retrieval device is lifted out of the wellhead to complete the milling and retrieval work.

[0044] It will be apparent to those skilled in the art that the present invention is not limited to the details of the exemplary embodiments described above, and that the invention can be implemented in other specific forms without departing from its spirit or essential characteristics. Therefore, the embodiments should be considered in all respects as exemplary and non-limiting, and the scope of the invention is defined by the appended claims rather than the foregoing description. Thus, all variations falling within the meaning and scope of equivalents of the claims are intended to be included within the present invention. No reference numerals in the claims should be construed as limiting the scope of the claims.

[0045] Furthermore, it should be understood that although this specification describes embodiments, not every embodiment contains only one independent technical solution. This narrative style is merely for clarity. Those skilled in the art should consider the specification as a whole, and the technical solutions in each embodiment can also be appropriately combined to form other embodiments that can be understood by those skilled in the art.

Claims

1. A milling and fishing device, characterized in that, Includes a bottom cylinder (1), a top cylinder (2) is provided above the bottom cylinder (1), an intermediate cylinder (3) is provided between the top cylinder (2) and the bottom cylinder (1), the top cylinder (2) is connected to the bottom cylinder (1) through the intermediate cylinder (3), and a connector (4) is provided above the top cylinder (2). The bottom cylinder (1) is fixedly connected to a first annular plate (101). A plurality of grinding teeth (102) are fixedly connected to one end of the first annular plate (101) away from the bottom cylinder (1), and the plurality of grinding teeth (102) are arranged in a ring array about the central axis of the first annular plate (101). The bottom cylinder (1) is provided with an anti-blocking component (5) inside its lower end, and a collection component (6) is provided inside its upper end. The middle cylinder (3) is provided with a conical cylinder (7) inside its interior. The anti-blocking component (5) includes a second annular plate (501), the outer wall of the second annular plate (501) is fixedly connected to the inner wall of the bottom cylinder (1), and a plurality of uniformly distributed through holes (503) are opened in the middle of the second annular plate (501). The second annular plate (501) is rotatably connected to a circular plate (502) via a bearing. A circular hole is provided in the middle of the circular plate (502), and a positioning rod (504) is slidably connected inside the circular hole. The bottom end of the positioning rod (504) is located below the circular plate (502) and is fixedly connected to a rubber pad (505). The top end of the positioning rod (504) is located above the circular plate (502) and is fixedly connected to a limiting plate (506). A spring (507) is sleeved on the outside of the top end of the positioning rod (504). The two ends of the spring (507) are fixedly connected to the limiting plate (506) and the circular plate (502) respectively. The rubber pad (505) is located below the grinding teeth (102). A fixing ring (508) is sleeved on the outside of the positioning rod (504) and below the circular plate (502). Connecting rods (509) are symmetrically fixed on both sides of the fixing ring (508), and the connecting rods (509) do not contact the bottom cylinder (1). A scraper (510) is fixedly connected to the side of the connecting rod (509) near the second annular plate (501). The collection assembly (6) includes a collection bucket (601), with a plurality of fixing rods (602) fixedly connected to the lower end of the collection bucket (601). The end of the fixing rod (602) away from the collection bucket (601) is fixedly connected to the inner wall of the bottom cylinder (1). A third annular plate (603) is fixedly connected to the top opening of the collection bucket (601). A plurality of elastic plates (604) are fixedly connected to the end of the third annular plate (603) away from the collection bucket (601). The plurality of elastic plates (604) are arranged in a ring array about the central axis of the third annular plate (603). There is a gap between two adjacent elastic plates (604). The plurality of elastic plates (604) together form a funnel shape. The end of the elastic plate (604) away from the third annular plate (603) is in contact with the inner wall of the bottom cylinder (1). The diameter of the collection bucket (601) is smaller than the inner diameter of the bottom cylinder (1). A material passage cavity is formed between the outer wall of the collection bucket (601) and the inner wall of the bottom cylinder (1). A conical block is fixedly connected to the bottom of the collection bucket (601), and the apex of the conical block is directly opposite the limiting plate (506).

2. The milling and fishing device according to claim 1, characterized in that, The inner wall of the upper end of the bottom cylinder (1), the inner wall of the upper end of the top cylinder (2) and the inner wall of the lower end are all provided with internal threads. The outer wall of the lower end of the connector (4), the outer wall of the upper end of the middle cylinder (3) and the outer wall of the lower end are all provided with external threads that are compatible with the internal threads.

3. The milling and fishing device according to claim 1, characterized in that, The upper and lower ends of the intermediate cylinder (3) are threaded to the lower end of the top cylinder (2) and the upper end of the bottom cylinder (1), respectively, and the lower end of the connector (4) is threaded to the upper end of the top cylinder (2).

4. The milling and fishing device according to claim 1, characterized in that, The inner diameters of the bottom cylinder (1), the middle cylinder (3), the top cylinder (2), and the connector (4) are all equal.

5. The milling and fishing device according to claim 1, characterized in that, A fourth annular plate is coaxially fixedly connected to the large end of the conical cylinder (7). The outer wall of the fourth annular plate is fixedly connected to the inner wall of the intermediate cylinder (3). The inner diameter of the fourth annular plate is equal to the inner diameter of the large end of the conical cylinder (7). The outer diameter of the large end of the conical cylinder (7) is smaller than the inner diameter of the intermediate cylinder (3). The outer wall of the conical cylinder (7), the upper surface of the fourth annular plate, and the inner wall of the intermediate cylinder (3) together form a collection trough.

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