A high efficiency reamer tool for handling downhole accidents

Abstract

The utility model discloses a kind of high efficiency reaming tools for handling downhole accident.The utility model relates to the field of oil drilling tool, more specifically to the reaming tool for handling downhole accident.The high efficiency reaming tool is composed of drill bit matrix and high efficiency milling ring fixedly connected at one end of drill bit matrix, characterized in that high efficiency milling ring adopts natural diamond and triangular polycrystalline baras combined tooth arrangement, inner and outer gage diameter are inlaid diamond.High efficiency milling ring adopts three-level concentric ridge inlaid tooth, second cutting layer can be provided on high efficiency milling ring, and the second cutting layer is PDC composite sheet.The number of inner and outer water channels is designed as odd number, and inner gage diameter water channel is designed as straight water channel, and outer gage diameter water channel is designed as inclined water channel, and the structure height is controllable and can be adjusted, convenient to use and wider application range.It can solve the problems of short service life, low reaming efficiency and poor safety of conventional milling ring.

Description

Technical Field

[0001] This utility model relates to the field of oil drilling tools, and more specifically to a high-efficiency milling tool for handling downhole accidents. Background Technology

[0002] As major oilfields gradually enter the mid-to-late stages of development and production, the reuse of old wellbores has become an important strategy for adjusting sidetracking and ensuring stable and increased production. The core of old wellbore reuse lies in meeting the actual needs of drilling and subsequent production, which requires effectively addressing the removal of shallow casing and deep sand control tubing. The removal of shallow casing mainly relies on casing milling.

[0003] During drilling and completion operations, some downhole accidents are often encountered, such as the drill string being stuck by sand or debris falling from the well wall, or the drill string being cemented due to an error in calculating the cement setting time during cementing, which is what we often call a "flagpole" accident.

[0004] In well completion operations, incidents such as packer or bridge plug jamming necessitate milling. Therefore, milling is ubiquitous and required throughout drilling, workover, and completion. Currently used milling tools primarily consist of carbide milling rings. However, their wear resistance and structural strength are insufficient for handling such harsh milling conditions. Issues include carbide detachment, short milling ring life, and low milling efficiency. This makes them unsuitable for prolonged continuous operation, complicates incident handling, and increases the risk of secondary accidents. Therefore, to address the problems of ordinary milling rings, a new milling tool is needed to handle downhole incidents, ensuring the safety, efficiency, and durability of milling operations. Utility Model Content

[0005] The purpose of this utility model is to provide a high-efficiency milling tool for handling downhole accidents in order to solve the above-mentioned technical problems.

[0006] To achieve the above objectives, this utility model specifically adopts the following technical solution: This utility model provides a high-efficiency milling tool for handling downhole accidents, comprising a drill bit body and a high-efficiency milling ring fixedly connected to one end of the drill bit body, characterized in that: The working end face of the high-efficiency milling ring is provided with a three-level concentric circular ridge structure; The cutting element of the high-efficiency milling ring includes a first cutting layer, which is composed of natural diamond particles and triangular polycrystalline diamonds embedded in the concentric ridge structure. The natural diamond particles are mainly distributed in the inner ring area, and the triangular polycrystalline diamonds are mainly distributed in the outer ring area.

[0007] Specifically, a second cutting layer, which is a PDC composite sheet, can be provided on the high-efficiency milling ring.

[0008] Specifically, the high-efficiency milling ring has an outer diameter and an inner diameter inlaid with diamonds, and is provided with a guide channel that runs through the inside and outside. The number of the guide channels is odd, and includes a straight channel for the inner diameter and an oblique channel for the outer diameter.

[0009] Specifically, the inclination angle of the outer diameter inclined channel is 10-20 degrees, and the inner diameter straight channel and the outer diameter inclined channel are staggered in the circumferential direction with an interlacing angle of 5-10 degrees.

[0010] Specifically, the edge height of the natural diamond particles is 0.8-1.0 mm, and the edge height of the triangular polycrystalline diamond is 1.5-2.0 mm.

[0011] Specifically, the diameter of the PDC composite sheet is 5-8mm, and the back tilt angle is 17-20 degrees.

[0012] Specifically, when used for milling harder formations, the PDC composite sheet adopts a double-row toothed design; when used for milling softer formations, it adopts a single-row toothed design.

[0013] The beneficial effects of this utility model are as follows: To overcome the aforementioned problems in existing technologies, a high-efficiency milling tool for handling downhole accidents is proposed, which can solve the problems of short service life, low milling efficiency, and poor safety of conventional milling rings.

[0014] This utility model can adopt different implementation schemes for different downhole accidents. The published high-efficiency milling tool has a controllable and adjustable structure height, is easy to use, and has a wider range of applications. Attached Figure Description

[0015] To more clearly illustrate the technical solutions of the embodiments of this utility model, the accompanying drawings used in the embodiments will be briefly introduced below. It should be understood that the following drawings only show some embodiments of this utility model and should not be regarded as a limitation on the scope. For those skilled in the art, other related drawings can be obtained from these drawings without creative effort.

[0016] Figure 1 This is a schematic diagram of the structure of the high-efficiency milling tool of this utility model; Figure 2 It is a mixed toothed structure of natural diamond and triangular polycrystalline Balas, as shown in the schematic diagram of the waterway design. Figure 3 This is a schematic diagram of the PDC gear milling ring of this utility model; Figure reference numerals: 1-Drill bit body, 2-High-efficiency milling ring, 3-Outer diameter protection, 4-Inner diameter protection, 5-Inner diameter protection straight water channel, 6-Outer diameter protection inclined water channel, 7-Natural diamond particle, 8-Triangular polycrystalline ballast, 9-PDC composite sheet. Detailed Implementation

[0017] To make the technical problems, technical solutions, and technical effects of this utility model clearer, the technical solutions of this utility model will be clearly and completely described below with reference to the accompanying drawings of the embodiments of this utility model. Obviously, the described embodiments are only some embodiments of this utility model, and not all embodiments. The components of the embodiments of this utility model described and shown in the accompanying drawings can generally be arranged and designed in various different configurations.

[0018] Therefore, the following detailed description of the embodiments of the present 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 present invention without inventive effort are within the scope of protection of the present invention.

[0019] In the description of the embodiments of this utility model, it should be noted that the terms "inner", "outer", "upper", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the drawings, or the orientation or positional relationship in which the utility model product is usually placed when in use. They are only for the convenience of describing this utility model and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this utility model.

[0020] Example 1 In this embodiment, for situations where the drill string falls into the well and other salvage methods fail to resolve the accident, it is necessary to mill the drill string couplings one by one and remove each drill pipe individually. To address this issue, a Black Diamond 7 three-level concentric circular ridge inlaid tooth method is used.

[0021] In this embodiment, the high-efficiency milling ring 2 is a thin-walled part, which is prone to cracking under pressure during use, leading to secondary accidents. To reduce this risk, the number of inner and outer water channels in the milling ring 2 is generally designed to be odd. The inner diameter water channel 5 is designed as a straight water channel, and the outer diameter water channel 6 is designed as an inclined water channel. The inclination angle of the inclined water channel is 10-20 degrees, and the inner and outer water channels need to be staggered to form a certain angle, with the included angle designed to be 5-10 degrees. Furthermore, the water channel width is designed to be 10-12mm, the thickness is designed to be 1.5-2mm, and the bottom water channel thickness is designed to be 3-4mm, which is conducive to the removal of iron chips from the milling process.

[0022] In this embodiment, 5-7 natural diamond particles 7 are used per CT, and the cutting edge height is designed to be 0.8-1.0 mm.

[0023] In this embodiment, the triangular polycrystalline material 8 uses 3 grains / CT, and the blade height is designed to be 1.5-2mm.

[0024] In this embodiment, triangular polycrystalline balas 8 are arranged in the outer ring area, and one row is arranged for each blade.

[0025] In this embodiment, the high-efficiency milling ring 2 adopts a three-level concentric circular ridge inlaid tooth, which can ensure better diamond encapsulation. Furthermore, the three-level concentric circular ridge inlaid tooth consists of a set of tooth structure area 1, tooth structure area 2 and tooth structure area 3, which are arranged repeatedly. The spatial staggered arrangement of areas 1, 2 and 3 can better ensure that the cutting element is fully covered at the bottom of the well, which is more conducive to ensuring the milling life.

[0026] In this embodiment, the drill string is stuck due to sand or debris falling off the well wall, which is a relatively simple downhole accident. It requires the milling tool to only mill the cuttings around the drill string. This is a common problem of low efficiency in conventional milling with two milling rings. To address this issue, the present invention uses a PDC composite sheet nine-milling tool for milling operations.

[0027] In this embodiment, when the drill string is stuck by sand or debris falling off the well wall, milling is performed by chelating a PDC composite piece with a high-efficiency milling ring of a milling tool. The high-efficiency milling ring is a thin-walled part, so the diameter of the PDC composite piece is selected as 5-8mm, the chamfer of the cutting teeth is designed as 0.6-0.8, and the back slope angle is designed as 17-20 degrees.

[0028] Furthermore, when the chipped material and sand deposits being milled are relatively hard, a double-row toothed design is adopted when milling PDC composite plates in high-efficiency milling rings to improve the service life of the milling tool.

[0029] Furthermore, when the chipped material and sand deposits being milled are relatively soft, a single-row toothed design is adopted when using high-efficiency milling rings to chelate PDC composite plates, ensuring the working efficiency of the milling tool.

[0030] Example 2 In response to downhole accidents involving flagpoles in oilfields, this utility model discloses a high-efficiency milling ring 2 with a combination of natural diamond particles 7 and triangular polycrystalline balas 8. The milling ring 2 has 5-7 natural diamond particles / carat 7 arranged in the inner ring area to effectively mill the wear-resistant zone of the drill pipe coupling for easy loosening. The triangular polycrystalline balas 8 arranged in the outer ring area effectively mills the cement sheath. The two cutting elements fully utilize their respective advantages, significantly improving milling efficiency. A three-stage concentric ridge tooth arrangement ensures full coverage of the cutting elements at the bottom of the well, guaranteeing service life. To ensure the service life and safety of the milling tool and reduce cracking, this design incorporates nine water channels. The outer channel has a 15-degree inclination angle, a 10mm width, and a 1.5mm thickness. The inner and outer channels intersect at an 8-degree angle. The bottom channel has a thickness of 3mm.

[0031] The above embodiments describe the basic principles, main features, and advantages of this utility model. Those skilled in the art should understand that this utility model is not limited to the above embodiments. The embodiments and descriptions in the specification are merely illustrative of the principles of this utility model. Modifications and variations made by those skilled in the art without departing from the spirit and scope of this utility model should be protected within the scope of the appended claims.

Claims

1. A high-efficiency milling tool for handling downhole accidents, comprising a drill bit body (1) and a high-efficiency milling ring (2) fixedly connected to one end of the drill bit body (1), characterized in that: The working end face of the high-efficiency milling ring (2) is provided with a three-level concentric circular ridge structure; The cutting element of the high-efficiency milling ring (2) includes a first cutting layer, which is composed of natural diamond particles (7) and triangular polycrystalline diamonds (8) embedded in the concentric ridge structure, wherein the natural diamond particles (7) are mainly distributed in the inner ring area and the triangular polycrystalline diamonds (8) are mainly distributed in the outer ring area.

2. The high-efficiency milling tool according to claim 1, characterized in that: A second cutting layer can be provided on the high-efficiency milling ring (2), which is a PDC composite sheet (9).

3. The high-efficiency milling tool according to claim 1 or 2, characterized in that: The high-efficiency milling ring (2) has an outer diameter (3) and an inner diameter (4) inlaid with diamonds, and is provided with a guide channel that runs through the inside and outside. The number of the guide channels is odd, and includes a straight channel (5) for the inner diameter and an oblique channel (6) for the outer diameter.

4. The high-efficiency milling tool according to claim 3, characterized in that: The inclination angle of the outer diameter inclined channel (6) is 10-20 degrees, and the inner diameter straight channel (5) and the outer diameter inclined channel (6) are staggered in the circumferential direction with an interlacing angle of 5-10 degrees.

5. The high-efficiency milling tool according to claim 1, characterized in that: The edge height of the natural diamond particle (7) is 0.8-1.0 mm, and the edge height of the triangular polycrystalline diamond (8) is 1.5-2.0 mm.

6. The high-efficiency milling tool according to claim 2, characterized in that: The PDC composite sheet (9) has a diameter of 5-8 mm and a back tilt angle of 17-20 degrees.

7. The high-efficiency milling tool according to claim 2 or 6, characterized in that: When used for milling harder formations, the PDC composite sheet (9) adopts a double-row tooth design; when used for milling softer formations, it adopts a single-row tooth design.

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