Horizontal well anti-eccentric-wear sleeve internally-cutting milling shoe

Abstract

The utility model provides a horizontal well anti-eccentric-wear sleeve internally-cutting milling shoe which comprises a milling shoe upper connector, a milling shoe body and a milling shoe lower connector which are sequentially connected from top to bottom. The lower part of the milling shoe body shell is sleeved with a centralizing cylinder; the milling shoe lower joint is positioned in the centralizing cylinder; communicated fluid passages are arranged in the milling shoe upper joint, the milling shoe body, the milling shoe lower joint and the centralizing cylinder; a hard alloy layer is arranged on the bottom surface of the milling shoe lower joint. The fluid channel comprises a first water passing hole vertically formed in the milling shoe upper connector, a second water passing hole vertically formed in the milling shoe body, a first milling shoe water hole obliquely formed in the milling shoe lower connector and a second milling shoe water hole obliquely formed in the centralizing cylinder. According to the utility model, the periphery of the drill rod to be ground is centralized integrally by virtue of the centralizing cylinder, the relative stability between the grinding shoe and the drill rod to be ground is ensured, and the alignment success rate and the grinding efficiency are high; in the process of grinding and milling in the casing, the centralizing cylinder does not rotate, the inner wall of the casing is sufficiently protected, and the well repairing difficulty is reduced.

Description

Technical Field

[0001] The utility model belongs to the technical field of tools for medium-deep geothermal development and workover operations, and particularly relates to an internal cutting grinding shoe for horizontal well casing to prevent eccentric wear. Background Art

[0002] With the continuous improvement of the technical level of medium- and deep-layer geothermal energy development and oil and gas field development, the wellbore structure has become increasingly complex. The horizontal well structure has become an advanced wellbore structure for the efficient development of medium- and deep-layer geothermal energy and oil and gas resources. At present, when the drill pipe breaks and gets stuck in the horizontal well casing and the fish needs to be milled, the existing milling shoe suitable for open hole wells is very prone to eccentric wear, resulting in damage to the casing wall and even abandonment of the well, which brings difficulties to the well repair operation. Therefore, it is urgent to develop an anti-eccentric wear casing cutting milling shoe suitable for use in the horizontal well casing. Utility Model Content

[0003] In view of the defects and deficiencies in the prior art, the utility model provides a horizontal well casing internal cutting mill shoe to prevent eccentric wear, so as to solve the technical problem that the prior art lacks a mill shoe suitable for milling drill pipes in horizontal well casings.

[0004] In order to achieve the above-mentioned purpose, the present invention adopts the following technical solutions:

[0005] A horizontal well casing internal cutting mill shoe for preventing eccentric wear, comprising a mill shoe upper joint, a mill shoe body and a mill shoe lower joint connected in sequence from top to bottom;

[0006] The lower part of the mill shoe body shell is covered with a straightening cylinder, and the mill shoe lower joint is located inside the straightening cylinder;

[0007] The mill shoe upper joint, the mill shoe body, the mill shoe lower joint and the straightening cylinder are provided with a communicating fluid passage;

[0008] The bottom surface of the lower joint of the grinding shoe is provided with a hard alloy layer.

[0009] The utility model also has the following technical features:

[0010] Specifically, the fluid passage includes a first water hole vertically arranged in the upper joint of the mill shoe, a second water hole vertically arranged in the mill shoe body, a first mill shoe water hole obliquely arranged in the lower joint of the mill shoe, and a second mill shoe water hole obliquely arranged in the straightening cylinder.

[0011] Furthermore, the first water hole and the second water hole are arranged to be coaxially connected with each other and have equal diameters.

[0012] Furthermore, the first mill shoe water hole and the second mill shoe water hole are arranged to be equal in diameter and coaxially connected.

[0013] Furthermore, the number of the first mill shoe water holes and the number of the second mill shoe water holes are both three, and the three first mill shoe water holes are arranged at equal intervals.

[0014] Furthermore, the cemented carbide particles are YD cemented carbide particles.

[0015] Furthermore, the angle between the first mill shoe water hole and the axis of the mill shoe body is 30-60 degrees, and the diameters of the first mill shoe water hole and the second mill shoe water hole are both 12 mm.

[0016] Furthermore, the lower end surface of the centralizing cylinder is lower than the bottom surface of the hard alloy layer, and the shape formed by the internal cavity of the lower end of the centralizing cylinder is a truncated cone.

[0017] Furthermore, the inner diameter of the straightening cylinder is larger than the outer diameter of the mill shoe body and the outer diameter of the mill shoe lower joint.

[0018] Compared with the prior art, the present invention has the following technical effects:

[0019] The utility model provides a horizontal well anti-eccentric wear casing inner cutting mill shoe, which realizes the overall straightening of the periphery of the mill shoe through the straightening cylinder installed at the lower part of the mill shoe body shell, ensuring that the entire milling process is carried out in a straightening and guiding state, and will not cause eccentric wear of the casing and uneven force, thereby improving the milling rate and efficiency; during the milling process in the casing, since the straightening cylinder does not rotate, it can fully protect the inner wall of the casing and reduce the difficulty of well repair. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 It is a schematic diagram of the overall structure of the utility model;

[0021] Figure 2 It is a cross-sectional view of the utility model;

[0022] Figure 3 It is a working schematic diagram of the utility model.

[0023] The numbers in the figure represent:

[0024] 1- mill shoe upper joint, 2- mill shoe body, 3- mill shoe lower joint, 4- straightening cylinder, 5- fluid passage, 6- carbide layer, 7- casing, 8- drill pipe; 51- first water hole, 52- second water hole, 53- first mill shoe water hole, 54- second mill shoe water hole. DETAILED DESCRIPTION

[0025] Specific embodiments of the present invention are given below. It should be noted that the present invention is not limited to the following specific embodiments, and all equivalent modifications made on the basis of the technical solution of this application fall within the protection scope of the present invention.

[0026] When describing the position of the present invention, it should be understood that Figure 1 Terms such as “upper”, “lower”, “front”, “back”, “left” and “right”, etc., indicating directions or positional relationships, are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific direction, be constructed and operate in a specific direction. Therefore, they should not be understood as limiting the present invention.

[0027] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be understood to indicate or imply relative importance or to implicitly indicate the quantity of the technical features indicated. Thus, a feature specified as "first" or "second" may explicitly or implicitly include one or more of the features.

[0028] Unless otherwise specified, all components in this invention are commercially available.

[0029] Example 1

[0030] Following the above technical solution, such as Figures 1 to 3 As shown, this embodiment provides a horizontal well casing internal cutting mill shoe for preventing eccentric wear, comprising a mill shoe upper joint 1, a mill shoe body 2, and a mill shoe lower joint 3, connected sequentially from top to bottom. A centering cylinder 4 is mounted on the lower portion of the mill shoe body 2, and the mill shoe lower joint 3 is located within the centering cylinder 4. A fluid passage 5 is provided within the mill shoe upper joint 1, the mill shoe body 2, the mill shoe lower joint 3, and the centering cylinder 4. A cemented carbide layer 6 is provided on the bottom surface of the mill shoe lower joint 3. The centering cylinder 4 serves to center the drill bit, facilitating the entry of the upper portion of the drill bit into the centering cylinder 4. This ensures that the entire milling process is carried out in a centering and guiding state, preventing eccentric wear of the casing and uneven force, thereby improving the milling rate and efficiency. The cemented carbide layer 6 is composed of cemented carbide particles welded onto the bottom surface of the mill shoe lower joint. The cemented carbide layer 6 is used to mill the upper end face of the drill bit.

[0031] As a preferred embodiment of this embodiment, the fluid passage 5 includes a first water hole 51 vertically disposed within the mill shoe upper joint 1, a second water hole 52 vertically disposed within the mill shoe body 2, a first mill shoe water hole 53 obliquely disposed within the mill shoe lower joint 3, and a second mill shoe water hole 54 obliquely disposed within the straightening cylinder 4. The fluid passage 5 is used to transport milling fluid. The provision of multiple first mill shoe water holes 53 and second mill shoe water holes 54 significantly improves circulation capacity during the milling process, facilitating the return of milled metal chips.

[0032] As a preferred solution of this embodiment, the first water through hole 51 and the second water through hole 52 are arranged to be in equal diameter and coaxially connected.

[0033] As a preferred solution of this embodiment, the first mill shoe water hole 53 and the second mill shoe water hole 54 are arranged to be of equal diameter and coaxially connected.

[0034] As a preferred solution of this embodiment, the number of the first mill shoe water holes 53 and the number of the second mill shoe water holes 54 are both three, and the three first mill shoe water holes 54 and the three second mill shoe water holes 54 are evenly spaced.

[0035] As a preferred solution of this embodiment, the cemented carbide particle layer 6 is a YD cemented carbide layer. The YD cemented carbide wear layer has high hardness, high strength, high wear resistance and high corrosion resistance.

[0036] As a preferred solution of this embodiment, the angle between the first mill shoe water hole 53 and the axis of the mill shoe body 2 is 30-60 degrees, and the diameters of the first mill shoe water hole 53 and the second mill shoe water hole 54 are both 12 mm.

[0037] As a preferred solution of this embodiment, the lower end surface of the centralizing cylinder 4 is lower than the bottom surface of the cemented carbide layer, and the shape of the internal cavity of the lower end of the centralizing cylinder 4 is a truncated cone, wherein the smaller diameter end of the truncated cone is close to the lower joint 3 of the mill shoe, and the larger diameter end of the truncated cone is away from the lower joint 3 of the mill shoe.

[0038] As a preferred embodiment of this embodiment, the inner diameter of the centering cylinder 4 is larger than the outer diameter of the mill shoe body 2 and the outer diameter of the mill shoe lower joint 3. In this embodiment, the outer diameter of the mill shoe body 2 is 120 mm, and the diameter of the centering cylinder 4 is 150 mm. That is, the maximum outer diameter of the mill shoe is 150 mm, and the minimum outer diameter is 120 mm. This is particularly suitable for milling drill pipe with a diameter of 89 mm in a 177.8 mm x N80 casing.

[0039] The use process of this utility model is as follows:

[0040] (1) Connect the milling string with the mill shoe upper joint, start the power system, and lower the mill shoe along with the milling string to a position 3 to 5 meters above the broken drill pipe 8 in the casing 7. Start the circulation pump to circulate the milling fluid. Under the guidance of the centralizing cylinder 4, the upper end of the drill bit enters the centralizing cylinder 4 until it touches the cemented carbide layer 6.

[0041] (2) The milling string is rotated to drive the mill shoe to rotate, and the upper end surface of the drill pipe 8 is trimmed through the carbide layer 6; during the whole process, the straightening cylinder 4 maintains the straightening effect outside the drill bit, and the straightening cylinder 4 does not rotate to maintain the overall stability of the device;

[0042] (3) After the drill pipe milling is completed in the casing 7, the power system is turned off, the milling shoe stops rotating, the milling fluid circulation pump is turned off, the milling string is lifted to the wellhead, and the milling shoe inside the horizontal well anti-eccentric wear casing is removed to complete the operation.

[0043] The above description is merely a preferred embodiment of the present invention and is not intended to limit the present invention. Those skilled in the art will readily appreciate that the present invention is susceptible to various modifications and variations. Any modifications, equivalent substitutions, or improvements made within the spirit and principles of the present invention shall be included within the scope of protection of the present invention.

Claims

1. A horizontal well anti-eccentric wear casing inner cutting shoe, characterized in that: The invention comprises a mill shoe upper joint (1), a mill shoe body (2) and a mill shoe lower joint (3) which are connected in sequence from top to bottom; a straightening cylinder (4) is mounted on the lower part of the outer shell of the mill shoe body (2), and the mill shoe lower joint (3) is located inside the straightening cylinder (4); a fluid passage (5) is provided in communication with the mill shoe upper joint (1), the mill shoe body (2), the mill shoe lower joint (3) and the straightening cylinder (4); and a hard alloy layer (6) is provided on the bottom surface of the mill shoe lower joint (3).

2. The horizontal well anti-eccentric wear casing inner cutting shoe according to claim 1, characterized in that: The fluid passage (5) comprises a first water hole (51) vertically arranged in the mill shoe upper joint (1), a second water hole (52) vertically arranged in the mill shoe body (2), a first mill shoe water hole (53) obliquely arranged in the mill shoe lower joint (3), and a second mill shoe water hole (54) obliquely arranged in the straightening cylinder (4).

3. The horizontal well anti-eccentric wear casing inner cutting shoe according to claim 2, characterized in that: The first water passage hole (51) and the second water passage hole (52) are arranged to be in equal diameter and coaxial communication with each other.

4. The horizontal well anti-eccentric wear casing inner cutting shoe according to claim 2, characterized in that: The first mill shoe water hole (53) and the second mill shoe water hole (54) are arranged to be in equal diameter and coaxial communication with each other.

5. The horizontal well anti-eccentric wear casing inner cutting shoe according to claim 2, characterized in that: The number of the first mill shoe water holes (53) and the number of the second mill shoe water holes (54) are both three, and the three first mill shoe water holes (53) and the three second mill shoe water holes (54) are evenly spaced.

6. The horizontal well anti-eccentric wear casing inner cutting shoe according to claim 1, characterized in that: The hard alloy layer (6) is a YD hard alloy layer.

7. The horizontal well anti-eccentric wear casing inner cutting shoe according to claim 2, characterized in that: The angle between the first mill shoe water hole (53) and the axis of the mill shoe body (2) is 30-60 degrees, and the diameters of the first mill shoe water hole (53) and the second mill shoe water hole (54) are both 12 mm.

8. The horizontal well anti-eccentric wear casing inner cutting shoe according to claim 1, characterized in that: The lower end surface of the centralizing cylinder (4) is lower than the bottom surface of the hard alloy layer, and the shape formed by the internal cavity of the lower end of the centralizing cylinder (4) is a truncated cone.

9. The horizontal well anti-eccentric wear casing inner cutting shoe according to claim 2, characterized in that: The inner diameter of the straightening cylinder (4) is larger than the outer diameter of the mill shoe body (2) and the outer diameter of the mill shoe lower joint (3).

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