Anti-eccentric-wear sleeve front guide milling shoe for milling drill rod

Abstract

The guide milling shoe comprises a cutter cylinder and a milling shoe assembly arranged in the cutter cylinder in a penetrating mode, the milling shoe assembly comprises a milling shoe body and a guide column which are coaxially connected, and the lower end of the guide column penetrates out of the bottom of the cutter cylinder; the guide column is sleeved with a first hard alloy body, and the lower end face of the first hard alloy body is provided with a first milling layer used for milling the upper end face of the drill rod. A water passing hole is vertically formed in the milling shoe body, a plurality of water hole openings are formed in the bottom of the water passing hole, each water hole opening is communicated with a first milling shoe water hole obliquely formed in the bottom of the milling shoe body, and each first milling shoe water hole is communicated with a second milling shoe water hole obliquely formed in the first hard alloy body; the cutter cylinder comprises a cutter cylinder body and a second hard alloy body arranged at the bottom of the cutter cylinder body, a second milling layer used for milling the circular bead of the drill rod joint is arranged on the bottom surface of the second hard alloy body, and a third milling layer used for milling the outer wall of the drill rod is arranged on the outer wall of the second hard alloy body.

Description

Technical Field

[0001] The invention belongs to the technical field of well repair operation tools for medium-deep geothermal development, and in particular relates to a front-mounted guide grinding shoe for anti-eccentric wear casing used for grinding and milling drill pipes. Background Art

[0002] With the increasing technical level of medium-deep geothermal energy development and oil and gas field development, the wellbore structure is becoming increasingly complex. The horizontal well structure has become an advanced wellbore structure for the efficient development of medium-deep geothermal energy and oil and gas resources. At present, when the drill pipe is broken and stuck in the horizontal well casing and needs to be milled, a groove is often made on the base of the mill shoe suitable for open hole wells to set a ball to achieve the purpose of anti-eccentric wear. However, since the bottom of the mill shoe head is still exposed and lacks a protective device, during use, the ball is very likely to be stuck and eccentrically wear the casing wall, and the contact area between the ball and the inner wall of the casing is relatively small. The pressure generated during use will also cause certain wear on the casing wall. Therefore, the existing mill shoe suitable for open hole wells is not suitable for the casing in the horizontal well section, which brings difficulties to the well repair operation of the horizontal well. Therefore, it is urgent to develop a guide mill shoe for milling of broken and stuck drill pipes in the casing of the horizontal well section. Summary of the invention

[0003] In view of the defects and shortcomings in the prior art, the present invention provides a front-mounted guide grinding shoe for anti-biased wear casing for grinding drill pipes, so as to solve the technical problem in the prior art that the inner wall of the casing is easily damaged due to the deviation of the grinding shoe when grinding drill pipes in the casing of a horizontal well section.

[0004] To achieve the above object, the present invention adopts the following technical scheme:

[0005] A pre-guided milling shoe with an anti-biased wear casing for milling drill rods comprises a cutter barrel and a milling shoe assembly inserted in the cutter barrel, wherein the milling shoe assembly comprises a milling shoe body and a guide column coaxially connected, and the lower end of the guide column passes through the bottom of the cutter barrel;

[0006] A first hard alloy body is sleeved on the guide column, the upper end surface of the first hard alloy body abuts against the lower end surface of the mill shoe body, and the lower end surface of the first hard alloy body is provided with a first milling layer for milling the upper end surface of the drill rod; a water hole is vertically provided in the mill shoe body, and a plurality of water holes are provided at the bottom of the water hole, each of which is connected to a first mill shoe water hole obliquely arranged at the bottom of the mill shoe body, and each of the first mill shoe water holes is connected to a second mill shoe water hole obliquely arranged in the first hard alloy body;

[0007] The cutter barrel comprises a cutter barrel body and a second cemented carbide body arranged at the bottom of the cutter barrel body, the bottom surface of the second cemented carbide body is provided with a second grinding layer for grinding the shoulder of the drill rod joint, and the outer wall of the second cemented carbide body is provided with a third grinding layer for grinding the outer wall of the drill rod.

[0008] The present invention also has the following technical features:

[0009] Specifically, a plurality of axially extending limiting tooth grooves are provided on the outer wall of the grinding shoe body; a plurality of axially extending limiting convex teeth are provided on the upper part of the inner wall of the knife barrel body, and the limiting convex teeth can be plugged and matched with the limiting tooth grooves.

[0010] Furthermore, a mill shoe joint is coaxially provided at the upper end of the mill shoe body, and a fastening joint is coaxially provided at the upper end of the mill shoe joint.

[0011] Furthermore, the knife barrel body includes a first connecting section, a second connecting section and a third connecting section which are integrally connected from top to bottom, the inner wall of the first connecting section is provided with the limiting convex teeth, and the upper end face of the first connecting section is connected to the bottom face of the fastening joint; a first stepped butt-fitting end face is formed at the connection between the second connecting section and the third connecting section, a second stepped butt-fitting end face is provided on the inner wall of the second cemented carbide body, and the first butt-fitting end face and the second butt-fitting end face can be butt-fitted.

[0012] Furthermore, the first mill shoe water hole and the second mill shoe water hole are arranged with equal diameter and coaxially.

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

[0014] Furthermore, the first cemented carbide body and the second cemented carbide body are both YD cemented carbide bodies.

[0015] Furthermore, a plurality of stop-loss copper strips are arranged at intervals on the outer wall of the knife cylinder.

[0016] Furthermore, the angle between the first mill shoe water hole and the mill shoe joint axis is 25-45 degrees, and the diameters of the first mill shoe water hole and the second mill shoe water hole are both 12 mm.

[0017] Compared with the prior art, the present invention has the following technical effects:

[0018] (1) The anti-eccentric wear casing front guide grinding shoe for grinding drill pipe provided by the present invention can be used for grinding drill pipe in the casing of medium-deep geothermal wells and horizontal well sections of oil and gas wells. In particular, by setting up multiple grinding layers, it is possible to grind different positions of the drill pipe in the casing; the cutter barrel body and the grinding shoe body are designed in a split type, which is convenient for the replacement of the cutter barrel and the effective transmission of the rotary torque; and the guide column is set to effectively guide and straighten, so as to avoid the eccentric wear of the grinding shoe during the grinding process to damage the casing.

[0019] (2) The present invention has a simple structure, small size, high efficiency, strong adaptability, safety and reliability, and can effectively improve milling efficiency, reduce well repair costs, and control well repair risks. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 It is a schematic diagram of the overall structure of the present invention;

[0021] Figure 2 It is a schematic diagram of the structure of the grinding shoe assembly of the present invention;

[0022] Figure 3 is a cross-sectional view of the present invention;

[0023] Figure 4 It is a working schematic diagram of the present invention.

[0024] The numbers in the figure represent:

[0025] 1-knife barrel, 2-milling shoe assembly, 3-first hard alloy body, 4-milling shoe joint, 5-fastening joint, 6-limiting tooth groove, 7-limiting convex tooth, 8-stop loss copper belt, 9-casing, 10-drill rod; 11-knife barrel body, 12-second hard alloy body; 21-milling shoe body, 22-guide column; 31-second milling shoe water eye; 111-first connecting section, 112-second connecting section, 113-third connecting section; 211-water hole, 212-water eye outlet, 213-first milling shoe water eye. DETAILED DESCRIPTION

[0026] 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 changes made on the basis of the technical solution of this application fall within the protection scope of the present invention.

[0027] When describing the position of the present invention, it should be understood that Figure 1 The terms "upper", "lower", "front", "back", "left" and "right" etc., which indicate 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 operated in a specific direction, and therefore should not be understood as limiting the present invention.

[0028] In addition, the terms "first" and "second" are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Thus, the features defined as "first" and "second" may explicitly or implicitly include one or more of the features.

[0029] Unless otherwise specified, all components in the present invention are commercially available.

[0030] Example 1

[0031] Following the above technical solution, such as Figures 1 to 3 As shown, this embodiment provides a pre-guided grinding shoe for anti-eccentric wear casing for grinding and milling drill rods, including a cutter barrel 1 and a grinding shoe assembly 2 inserted in the cutter barrel 1, the grinding shoe assembly 1 includes a grinding shoe body 21 and a guide column 22 coaxially connected, and the lower end of the guide column 22 passes through the bottom of the cutter barrel 1; in this embodiment, the length of the guide column 22 is 130 mm, the diameter is 40 mm, and the bottom of the guide column 22 is semicircular. The combination of the guide 1 and the guide column 22 can play an effective guiding and straightening role in the process of grinding and milling drill rods to prevent eccentric wear from damaging the inner wall of the casing.

[0032] The guide column 22 is sleeved with a first hard alloy body 3, the upper end surface of the first hard alloy body 3 abuts against the lower end surface of the mill shoe body 21, and the lower end surface of the first hard alloy body 3 is provided with a first milling layer for milling the upper end surface of the drill rod; a water hole 211 is vertically provided in the mill shoe body 21, and a plurality of water holes 212 are provided at the bottom of the water hole 211, each of the water holes 212 is connected to a first mill shoe water hole 213 obliquely arranged at the bottom of the mill shoe body 21, and each of the first mill shoe water holes 213 is connected to a second mill shoe water hole 31 obliquely arranged in the first hard alloy body 3;

[0033] The cutter barrel 1 includes a cutter barrel body 11 and a second cemented carbide body 12 arranged at the bottom of the cutter barrel body 11, the bottom surface of the second cemented carbide body 12 is provided with a second grinding layer for grinding the shoulder of the drill rod joint, and the outer wall of the second cemented carbide body 12 is provided with a third grinding layer for grinding the outer wall of the drill rod.

[0034] In this embodiment, the grinding shoe assembly 2 and the cutter barrel 1 are both made of high-strength alloy material, which has strong tensile and compressive strength to avoid the possibility of joint breakage during the grinding process. Different positions of the drill rod are ground by setting different grinding layers.

[0035] As a preferred solution of this embodiment, Figure 2 and Figure 3As shown, a plurality of axially extending limiting tooth grooves 6 are provided on the outer wall of the grinding shoe body 21; a plurality of axially extending limiting convex teeth 7 are provided on the upper inner wall of the knife barrel body 11, and the limiting convex teeth 7 can be plugged in and matched with the limiting tooth grooves 6. This plug-in matching method is convenient for replacing the knife barrel 1 and can effectively transmit the rotational torque to the knife barrel 1, so that it has a strong grinding ability.

[0036] As a preferred solution of this embodiment, the upper end of the mill shoe body 21 is coaxially connected with a mill shoe joint 4, and the upper end of the mill shoe joint 4 is coaxially connected with a fastening joint 5, and the outer wall of the fastening joint 5 is provided with an external thread, and the fastening joint 5 is used to connect the milling pipe column and can be threadedly connected with the milling pipe column. The inner wall of the fastening joint 5 fits the outer wall of the mill shoe joint 4, and the inner hole of the fastening joint 5, the inner hole of the mill shoe joint 4 and the water hole 211 are coaxially connected with equal diameters.

[0037] As a preferred solution of this embodiment, the knife barrel body 11 includes a first connecting section 111, a second connecting section 112 and a third connecting section 113 which are integrally connected from top to bottom, the inner wall of the first connecting section 111 is provided with the limiting convex teeth 7, and the upper end face of the first connecting section 111 is connected to the bottom face of the fastening joint 5; the second connecting section 112 and the third connecting section 113 form a stepped first docking end face at the connection, and a stepped second docking end face is provided on the inner wall of the second cemented carbide body 12, and the first docking end face and the second docking end face can dock with each other. Preferably, the second cemented carbide body 12 is a frustum-shaped cone to reduce the risk of the second cemented carbide body 12 causing wear on the inner wall of the sleeve.

[0038] As a preferred solution of this embodiment, the first mill shoe water hole 213 and the second mill shoe water hole 31 are arranged with equal diameter and coaxially.

[0039] As a preferred solution of this embodiment, the number of the first mill shoe water holes 213 and the number of the second mill shoe water holes 31 are both four, and the four first mill shoe water holes 213 are arranged at equal intervals.

[0040] As a preferred solution of this embodiment, the first cemented carbide body 1 and the second cemented carbide body 12 are both YD cemented carbide bodies.

[0041] As a preferred solution of this embodiment, a plurality of stop-loss copper strips 8 are arranged at intervals on the outer wall of the knife barrel body 21. The stop-loss copper strips 6 are 10 mm long, 5 mm thick, and arranged at intervals of 50 mm, and are used to prevent the grinding shoe joint 1 from wearing the inner wall of the casing.

[0042] As a preferred solution of this embodiment, the angle between the first mill shoe water hole 213 and the axis of the mill shoe joint 4 is 25-45°, and the diameters of the first mill shoe water hole 213 and the second mill shoe water hole 31 are both 12 mm.

[0043] The use process of the present invention is as follows: Figure 4 As shown:

[0044] (1) The knife barrel 1 is connected to the milling shoe assembly 2 by means of the limiting protruding teeth 7 and the limiting tooth grooves 6, and then the milling shoe joint 4 and the fastening joint 5 are installed to limit the position of the guide body 11. The assembled guide milling shoe is connected to the bottom end of the milling pipe string by means of the fastening joint 5, and is lowered with the pipe string to a position 8 to 10 meters above the broken drill pipe 10 in the casing 9, and the circulation pump is turned on to circulate the milling fluid;

[0045] (2) Start the milling power system, the pipe string drives the front guide grinding shoe of the anti-eccentric wear casing to rotate, and slowly lower the pipe string so that the guide column 22 enters the central channel of the broken drill pipe 10, and the bottom end of the cutter barrel 2 is sleeved outside the broken drill pipe 10, and the guide column 22 and the cutter barrel 2 are used to achieve the guide straightening;

[0046] (3) Continue to slowly lower the pipe string. According to the observation of the index on the weight gauge, when the drilling pressure of the guide mill is reached, the first grinding layer at the lower end of the first cemented carbide body 3 begins to grind the drill pipe 10. When the drilling pressure increases and the grinding speed decreases, the second cemented carbide body 22 begins to grind the shoulder of the joint of the drill pipe 10. The metal chips generated by the grinding can be discharged from the annulus to the wellhead along with the grinding fluid.

[0047] (4) After the broken drill pipe in the casing is milled, the guide milling shoe stops rotating, the milling fluid circulation pump is turned off, the pipe string is lifted to the wellhead, and the guide milling shoe is removed.

[0048] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. For those skilled in the art, the present invention may have various modifications and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. A pre-guided grinding shoe with an anti-biased wear casing for grinding drill rods, comprising a cutter barrel (1) and a grinding shoe assembly (2) inserted into the cutter barrel (1), wherein the grinding shoe assembly (1) comprises a grinding shoe body (21) and a guide column (22) coaxially connected, and the lower end of the guide column (22) extends out from the bottom of the cutter barrel (1); A first hard alloy body (3) is sleeved on the guide column (22), the upper end surface of the first hard alloy body (3) abuts against the lower end surface of the mill shoe body (21), and the lower end surface of the first hard alloy body (3) is provided with a first milling layer for milling the upper end surface of the drill rod; a water hole (211) is vertically provided in the mill shoe body (21), a plurality of water holes (212) are provided at the bottom of the water hole (211), each of the water holes (212) is connected to a first mill shoe water hole (213) obliquely arranged at the bottom of the mill shoe body (21), and each of the first mill shoe water holes (213) is connected to a second mill shoe water hole (31) obliquely arranged in the first hard alloy body (3); The cutter barrel (1) comprises a cutter barrel body (11) and a second hard alloy body (12) arranged at the bottom of the cutter barrel body (11); the bottom surface of the second hard alloy body (12) is provided with a second grinding layer for grinding a shoulder of a drill rod joint; and the outer wall of the second hard alloy body (12) is provided with a third grinding layer for grinding an outer wall of a drill rod.

2. The anti-eccentric wear casing front guide grinding shoe for grinding drill rods according to claim 1 is characterized in that: The outer wall of the grinding shoe body (21) is provided with a plurality of axially extending limiting tooth grooves (6); the upper part of the inner wall of the knife barrel body (11) is provided with a plurality of axially extending limiting protruding teeth (7), and the limiting protruding teeth (7) can be plugged into and matched with the limiting tooth grooves (6).

3. The anti-eccentric wear casing front guide grinding shoe for grinding drill rods as claimed in claim 2, characterized in that: The upper end of the mill shoe body (21) is coaxially connected to a mill shoe joint (4), and the upper end of the mill shoe joint (4) is coaxially connected to a fastening joint (5).

4. The anti-eccentric wear casing front guide grinding shoe for grinding drill rods as claimed in claim 3, characterized in that: The knife barrel body (11) comprises a first connecting section (111), a second connecting section (112) and a third connecting section (113) which are integrally connected from top to bottom, the inner wall of the first connecting section (111) is provided with the limiting convex teeth (7), and the upper end face of the first connecting section (111) is connected to the bottom face of the fastening joint (5); a stepped first butt-fitting end face is formed at the connection between the second connecting section (112) and the third connecting section (113), and a stepped second butt-fitting end face is provided on the inner wall of the second cemented carbide body (12), and the first butt-fitting end face and the second butt-fitting end face can be butt-fitted.

5. The anti-eccentric wear casing front guide grinding shoe for grinding and milling drill rods according to claim 1, characterized in that: The first mill shoe water hole (213) and the second mill shoe water hole (31) are arranged with equal diameter and coaxially.

6. The anti-eccentric wear casing front guide grinding shoe for grinding drill rods as claimed in claim 1, characterized in that: The number of the first mill shoe water holes (213) and the number of the second mill shoe water holes (31) are both four, and the four first mill shoe water holes (213) are arranged at equal intervals.

7. The anti-eccentric wear casing front guide grinding shoe for grinding drill rods as claimed in claim 1, characterized in that: The first cemented carbide body (1) and the second cemented carbide body (12) are both YD cemented carbide bodies.

8. The anti-eccentric wear casing front guide grinding shoe for grinding drill rods as claimed in claim 1, characterized in that: A plurality of stop-loss copper strips (8) are arranged at intervals on the outer wall of the knife barrel body (21).

9. The anti-eccentric wear casing front guide grinding shoe for grinding drill rods as claimed in claim 1, characterized in that: The angle between the first mill shoe water hole (213) and the axis of the mill shoe joint (4) is 25-45°, and the diameters of the first mill shoe water hole (213) and the second mill shoe water hole (31) are both 12 mm.

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