A well-drainage device

Abstract

This invention discloses a well-clearing device, relating to the field of oil drilling engineering technology. The device includes a first milling column and a second milling column. The first milling column has a first cutting outer diameter. The second milling column is connected to the first milling column, and its second cutting outer diameter is adjustable, with the first cutting outer diameter falling within the adjustment range of the second cutting outer diameter. This well-clearing device can improve well-clearing efficiency and reduce well-clearing costs.

Description

Technical Field

[0001] This invention relates to the field of oil drilling engineering technology, and in particular to a well cleaning device. Background Technology

[0002] Some existing oil and gas fields have water-flooded wells that have been shut down for a long time, as well as low-yield and inefficient wells. For these wells, the old well casing window side-drilling technology is usually required as an effective technical means to tap the potential and increase efficiency of old oil fields and make use of remaining production capacity.

[0003] Currently, the mainstream technology for horizontal well fracturing is generally open-hole packer + sliding sleeve fracturing technology. Well cleaning process is the foundation for successfully running open-hole fracturing tools. Well cleaning process is mainly divided into two types according to different functions: single milling column and double milling column simulated open-hole fracturing tool rigid well cleaning in the open-hole section. Ultimately, different well cleaning processes need to be achieved through well cleaning tools.

[0004] Existing wellbore cleaning processes typically employ single or dual milling columns to simulate rigid wellbore cleaning using open-hole fracturing tools. The underlying principle usually involves brazing cemented carbide blocks and YD welding rods onto the surface of the drill string stabilizer. Furthermore, current wellbore cleaning processes require sequential window repair and open-hole reaming drilling, making it impossible to complete drilling in a single run. Only after one single milling column operation can a second single milling column be added to passively pull out the drill string, forming a dual-milling column drill string combination to simulate the rigidity of open-hole fracturing tools for secondary wellbore cleaning. However, the cost of pulling out a milling column is high, and this method significantly reduces drilling efficiency.

[0005] Therefore, there is an urgent need for a well-clearing device to solve the above problems. Summary of the Invention

[0006] The purpose of this invention is to provide a well cleaning device that can improve well cleaning efficiency and reduce well cleaning costs.

[0007] To achieve the above-mentioned technical effects, the technical solution of the present invention is as follows:

[0008] A well-drainage device includes: a first milling column having a first cutting outer diameter; and a second milling column connected to the first milling column, wherein the second cutting outer diameter of the second milling column is adjustable, and the first cutting outer diameter falls within the adjustment range of the second cutting outer diameter.

[0009] Furthermore, the second milling column includes: a main body connected to the first milling column; and a plurality of cutting elements, each of which is movably disposed within the main body.

[0010] Furthermore, the multiple cutting elements are divided into multiple cutting groups, which are distributed at intervals on the outer peripheral wall of the main body. Each cutting group includes multiple cutting elements spaced apart along the spiral direction of the main body.

[0011] Furthermore, the second milling column also includes a pusher, which passes through the main body. One end of the plurality of cutting elements abuts against the pusher, and when the pusher moves along the axial direction of the main body, it can push the plurality of cutting elements to extend out of the main body respectively.

[0012] Furthermore, the pusher is provided with multiple conical sections, and the ends of the multiple cutting parts are provided with oblique mating surfaces, which are adapted to the conical sections.

[0013] Furthermore, the cutting component includes: a cutting portion, one end of which abuts against the pushing component; and a limiting portion, which is used to restrict the cutting portion from detaching from the main body.

[0014] Furthermore, the cutting member also includes a retaining portion disposed within the cutting portion, the retaining portion being used to retain the cutting portion within the body.

[0015] Furthermore, the second milling column also includes a stop mechanism, which is disposed within the main body and abuts against the end of the pusher. When the stop mechanism is subjected to pressure, it can disengage from the main body so that the pusher can move relative to the main body.

[0016] Furthermore, the second milling column also includes a backstop, which is disposed on the inner wall of the main body and is used to restrict the pusher from moving unidirectionally along the axial direction of the main body.

[0017] Furthermore, the well-drainage device also includes a connector, the two ends of which are respectively connected to the first milling column and the second milling column, and the outer diameter of the connector is smaller than the first cutting outer diameter.

[0018] The beneficial effects of this invention are as follows:

[0019] The first milling column is inserted into the oil well, allowing it to cut the inner wall of the well during the well-running process. After the inner diameter of the well is cut, it is located at the first cutting outer diameter. At this time, the second cutting outer diameter of the second milling column can be adjusted to be smaller than the first cutting outer diameter. This allows the second milling column to continue cutting the well downwards with the first milling column without being blocked by the irregular well. This enables the first and second milling columns to form a simulated segmented fracturing tool string and be drilled down to the well window for window repair. The tool string is then continued to be run into the open hole section for well-running and enlargement / reduction of the well section, and finally to the bottom of the well. Subsequently, the well-drilling device is short-lifted to the position above the window. At this point, the second cutting outer diameter of the second milling column can be adjusted to be equal to the first cutting outer diameter, thus eliminating the need to completely remove the first milling column from the well. This avoids the tripping process of the well-drilling device and allows the first and second milling columns, with their first and second cutting outer diameters respectively, to be formed into a simulated segmented fracturing tool string, enabling it to complete the well-drilling process more effectively. After short-lifting, the first and second milling columns, with their first cutting outer diameters respectively, can be drilled down to dry-drill the well, achieving well-drilling in one trip. Therefore, well-drilling efficiency is greatly improved and drilling costs are reduced.

[0020] Additional aspects and advantages of the invention will be set forth in part in the description which follows, and in part will be obvious from the description, or may be learned by practice of the invention. Attached Figure Description

[0021] Figure 1 This is a schematic diagram of the well-drainage device provided in a specific embodiment of the present invention;

[0022] Figure 2 This is one of the structural schematic diagrams of the second milling column provided in a specific embodiment of the present invention;

[0023] Figure 3 yes Figure 2 A magnified schematic diagram of the partial structure at point A in the middle;

[0024] Figure 4 yes Figure 2 Sectional view at point BB;

[0025] Figure 5 yes Figure 2 Sectional view at CC;

[0026] Figure 6 This is the second structural schematic diagram of the second milling column provided in a specific embodiment of the present invention;

[0027] Figure 7 yes Figure 6 A magnified schematic diagram of the local structure at point D;

[0028] Figure 8 yes Figure 6 Sectional view at EE;

[0029] Figure 9 yes Figure 6 Sectional view at FF.

[0030] Figure Labels

[0031] 1. First milling column;

[0032] 2. Second milling column; 21. Main body; 22. Cutting part; 221. Oblique mating surface; 222. Cutting section; 223. Limiting section; 224. Holding section; 23. Pushing part; 231. Conical section; 24. Stopping mechanism; 25. Anti-reverse part;

[0033] 3. Connecting parts; 4. Steel balls; 5. Seals; 6. Shear pins. Detailed Implementation

[0034] To make the technical problems solved by the present invention, the technical solutions adopted, and the technical effects achieved clearer, the technical solutions of the present invention will be further described below in conjunction with the accompanying drawings and specific embodiments.

[0035] In the description of this invention, unless otherwise explicitly specified and limited, the terms "connected," "linked," and "fixed" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components. Those skilled in the art can understand the specific meaning of the above terms in this invention based on the specific circumstances.

[0036] In this invention, unless otherwise explicitly specified and limited, "above" or "below" the second feature can include direct contact between the first and second features, or contact between the first and second features through another feature between them. Furthermore, "above," "over," and "on top" of the second feature includes the first feature directly above or diagonally above the second feature, or simply indicates that the first feature is at a higher horizontal level than the second feature. "Below," "below," and "under" the second feature includes the first feature directly below or diagonally below the second feature, or simply indicates that the first feature is at a lower horizontal level than the second feature.

[0037] It should be understood that the terms "center," "longitudinal," "lateral," "length," "width," "thickness," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," "outer," "clockwise," "counterclockwise," "axial," "radial," and "circumferential," etc., indicating orientation or positional relationships, are based on the orientation or positional relationships shown in the accompanying drawings and are only for the convenience of describing the invention 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, and therefore should not be construed as a limitation of the invention. In the description of the invention, unless otherwise stated, "a plurality of" means two or more. Furthermore, the terms "first" and "second" are only used for descriptive distinction and have no special meaning.

[0038] The following is for reference. Figures 1-9 The specific structure of the well-drainage device according to an embodiment of the present invention is described.

[0039] like Figures 1-9 As shown, Figure 1 A well-drainage device is disclosed, comprising a first milling column 1 and a second milling column 2. The first milling column 1 has a first cutting outer diameter. The second milling column 2 is connected to the first milling column 1, and the second cutting outer diameter of the second milling column 2 is adjustable, with the first cutting outer diameter falling within the adjustment range of the second cutting outer diameter.

[0040] It is understandable that the first milling column 1 is inserted into the oil well so that it can cut the inner wall of the oil well during the well-running process. After the inner diameter of the oil well is cut, it is located at the first cutting outer diameter. At this time, the second cutting outer diameter of the second milling column 2 can be adjusted to be smaller than the first cutting outer diameter. This allows the second milling column 2 to continue cutting the oil well downward with the first milling column 1 without being blocked by the irregular oil well. This enables the first milling column 1 and the second milling column 2 to form a simulated segmented fracturing tool string and be drilled down to the window of the oil well for window repair, and continue to be run into the open hole section for well-running and enlargement and repair of the reduced diameter section, and finally to the bottom of the well. Subsequently, the well-drilling device is short-lifted to the position above the window. At this point, the second cutting outer diameter of the second milling column 2 can be adjusted to be equal to the first cutting outer diameter, thus eliminating the need to completely remove the first milling column 1 from the well. This avoids the tripping process of the well-drilling device and allows the first and second milling columns 1 and 2, with their first and second cutting outer diameters respectively, to form a simulated segmented fracturing tool string, enabling them to complete the well-drilling process more effectively. After short-lifting, the first and second milling columns 1 and 2, with their first cutting outer diameters respectively, can be drilled down to dry-drill the well, achieving well-drilling in one trip. Therefore, well-drilling efficiency is greatly improved and drilling costs are reduced.

[0041] Specifically, the well-clearing device of this embodiment greatly improves the efficiency of well-clearing construction during open-hole segmented fracturing. In actual construction, it can shorten the well completion cycle by 3 to 5 days. The fixed cost per well is 50,000 yuan per day, saving 150,000 to 250,000 yuan per well. Approximately 15 open-hole segmented fracturing operations are carried out annually for side-drilled horizontal wells. The market size is expected to reach 6.75 million to 11.25 million yuan in the next 3 years.

[0042] The well-clearing device according to this embodiment overcomes the drawback of the existing milling column device which requires two trips to start and stop drilling. It can achieve single-milling column drilling, double-milling column window repair, and hole enlargement in one trip. Without changing the existing well-clearing process, it can achieve the goal of changing the existing two-trip well-clearing process to one-trip well-clearing process, thereby improving well-clearing efficiency and reducing well-clearing costs.

[0043] In some embodiments, such as Figures 2-9 As shown, the second milling column 2 includes a main body 21 and multiple cutting elements 22, with the main body 21 connected to the first milling column 1. The multiple cutting elements 22 are movably inserted into the main body 21.

[0044] Understandably, when the multiple cutting elements 22 extend and retract within the main body 21, the distance between the cutting ends of the multiple cutting elements 22 and the outer wall of the main body 21 is also adjusted accordingly, thereby achieving an adjustable setting of the second cutting outer diameter of the second milling column 2. When the second milling column 2 is used for the first wellbore clearance with the first milling column 1, the multiple cutting elements 22 retract into the main body 21 to ensure that the second milling column 2 does not interfere with the wellbore clearance descent of the first milling column 1. When the first milling column 1 is raised, the multiple cutting elements 22 can extend out of the main body 21, thereby changing the second cutting outer diameter of the second milling column 2 to the first cutting outer diameter, so as to better achieve dry drilling clearance.

[0045] In some embodiments, such as Figure 2 and Figure 6 As shown, the multiple cutting parts 22 are divided into multiple cutting groups, which are distributed at intervals on the outer peripheral wall of the main body 21. Each cutting group includes multiple cutting parts 22 that are spaced apart along the spiral direction of the main body 21.

[0046] Understandably, multiple cutting groups can achieve better cutting results. The multiple cutting parts 22 of each cutting group are spaced apart along the spiral direction of the main body 21. When the main body 21 rotates, it can further drive the multiple cutting parts 22 to better cut the well wall, thereby improving the well clearance quality.

[0047] In some embodiments, such as Figure 4 , Figure 5 , Figure 8 and Figure 9As shown, the second milling column 2 also includes a pusher 23, which is inserted into the main body 21. One end of a plurality of cutting elements 22 abuts against the pusher 23. When the pusher 23 moves along the axial direction of the main body 21, it can push the plurality of cutting elements 22 to extend out of the main body 21 respectively.

[0048] It is understandable that when the first milling post 1 is before the short start, such as Figure 4 and Figure 5 As shown, the pusher 23 does not push the multiple cutting parts 22 to move radially along the main body 21. At this time, the cutting surfaces of the multiple cutting parts 22 are flush with the outer peripheral wall of the main body 21, making the second cutting outer diameter of the second milling column 2 smaller than the first cutting outer diameter; when the second milling column 2 is short-started, as... Figure 8 and Figure 9 As shown, the pusher 23 pushes multiple cutting elements 22 to move radially along the main body 21 and extend them outside the main body 21. At this time, the cutting surfaces of the multiple cutting elements 22 extend beyond the outer peripheral wall of the main body 21, making the second cutting outer diameter of the second milling column 2 greater than or equal to the first cutting outer diameter. Thus, by setting the pusher 23, the adjustment of the second cutting outer diameter of the second milling column 2 from the outside of the oil well is better realized, improving the convenience of adjusting the second cutting outer diameter.

[0049] In some specific embodiments, such as Figure 3 and Figure 7 As shown, the pusher 23 is connected to the inner wall of the main body 21 by a shear pin 6. After short-circuiting, pressurized fluid can be introduced into the main body 21 so that the shear pin 6 is disengaged under the pressure of the pusher 23, thereby realizing the movement of the pusher 23 relative to the main body 21 and ensuring that the pusher 23 will not move relative to the main body 21 before short-circuiting, ensuring that the movement of the entire well-drainage device will not be restricted before short-circuiting.

[0050] In some embodiments, such as Figure 5 and Figure 9 As shown, the pusher 23 is provided with multiple conical sections 231, and the ends of multiple cutting parts 22 are provided with oblique mating surfaces 221, which are adapted to the conical sections 231.

[0051] It is understandable that, through the cooperation of the conical section 231 and the oblique mating surface 221, the axial movement of the pushing member 23 in the body can be converted into the radial movement of the cutting member 22 in the body, thereby realizing the extension and retraction movement of multiple cutting members 22 relative to the body. In addition, by setting multiple conical sections 231, it can be ensured that multiple cutting members 22 can move relative to the body simultaneously, thus better guaranteeing cutting reliability.

[0052] In some embodiments, such as Figure 4 and Figure 8As shown, the cutting member 22 includes a cutting portion 222 and a limiting portion 223. One end of the cutting portion 222 abuts against the pushing member 23. The limiting portion 223 is used to prevent the cutting portion 222 from disengaging from the main body 21.

[0053] Understandably, the limiting part 223 can prevent the cutting part 222 from disengaging from the body after short-circuiting, so as to better ensure the reliable cutting of the cutting part 222.

[0054] Specifically, mounting holes are provided on both the main body 21 and the cutting part 222. The inner diameter of the mounting hole is larger than the outer diameter of the limiting part 223, so that the cutting part 222 can move while the limiting part 223 can limit the cutting part 222.

[0055] Specifically, the limiting part 223 includes a limiting bolt.

[0056] In some specific embodiments, the cutting part 222 is also provided with YG8 cemented carbide, which can further improve the cutting quality of the cutting part 222.

[0057] In some embodiments, such as Figure 4 and Figure 8 As shown, the cutting part 22 also includes a retaining part 224, which is provided inside the cutting part 222 and is used to retain the cutting part 222 inside the main body 21.

[0058] Understandably, the retaining part 224 can keep the cutting part 222 inside the body 21, thereby preventing the cutting part 222 from protruding from the body 21 before shorting.

[0059] Specifically, the retaining part 224 includes a spring, one end of which is connected to the limiting part 223, and the other end is connected to the cutting part 222. The spring tension ensures that the cutting part 222 does not extend out of the body. In other embodiments of the present invention, the retaining part 224 may also be configured as a shear pin 6 that unlocks under pressure, and its specific structure does not need to be specifically limited.

[0060] In some embodiments, such as Figure 3 and Figure 7 As shown, the second milling column 2 also includes a stop mechanism 24, which is located inside the main body 21 and abuts against the end of the pusher 23. When the stop mechanism 24 is subjected to pressure, it can be dislodged from the main body 21 so that the pusher 23 can move relative to the main body 21.

[0061] Understandably, the stop mechanism 24 allows the operator to apply pressure to it from the outside of the second milling column 2, thereby unlocking the pusher 23 and improving the ease of unlocking it. Furthermore, the stop mechanism 24 enables the pusher 23 of the second milling column 2 to be unlocked in different drill string combinations, allowing for changes to the tool string repair window and hole enlargement, thus enhancing the flexibility and applicability of the well cleaning system.

[0062] Specifically, in this embodiment, as Figure 7 As shown, the stop mechanism 24 includes a ball seat, which is connected to the pusher 23 by a shear pin 6. The operator can insert a steel ball 4 to make the steel ball 4 seal with the through hole of the ball seat, and then use hydraulic pressure of 18 MPa to make the ball seat separate from the pusher 23 and fall off the main body 21.

[0063] In some specific embodiments, such as Figure 3 and Figure 7 As shown, a sealing element 5 is provided between the stop mechanism 24 and the pusher 23, and a sealing element 5 is also provided between the pusher 23 and the inner wall of the main body 21, thereby ensuring the reliability of applying pressure to the stop mechanism 24 by hydraulic pressure, and ensuring the reliability of pushing the pusher 23 to move by hydraulic pressure.

[0064] In some embodiments, such as Figure 3 and Figure 7 As shown, the second milling column 2 also includes a backstop 25, which is located on the inner wall of the main body 21. The backstop 25 is used to restrict the pusher 23 from moving unidirectionally along the axial direction of the main body 21.

[0065] It is understandable that the anti-reverse component 25 can prevent the pusher 23 from coming out of the main body 21 and also prevent the pusher 23 from moving in the other direction along the axial direction of the main body 21. This ensures that the dimensions of the multiple cutting components 22 extending out of the main body 21 remain stable during the cutting process, thereby ensuring that the second cutting outer diameter of the second milling column 2 remains stable during the cutting process, thus improving the cutting reliability.

[0066] Specifically, in this embodiment, the anti-reverse component 25 includes an anti-reverse ring, one side of which has an opening, and the anti-reverse ring is connected to the main body 21 by a one-way thread.

[0067] In some embodiments, such as Figure 1 As shown, the well-drainage device also includes a connector 3, the two ends of which are connected to the first milling column 1 and the second milling column 2 respectively. The outer diameter of the connector 3 is smaller than the first cutting outer diameter.

[0068] It is understandable that the connector 3 can effectively connect the first milling column 1 and the second milling column 2, and its outer diameter is smaller than the first cutting outer diameter, so it will not interfere with the well passage of the first milling column 1 and the second milling column 2.

[0069] Specifically, in this embodiment, the connector 3 is a drill rod, and its specific connection structure with the first milling post 1 and the second milling post 2 can adopt the relevant structure in the prior art, which need not be described in detail here.

[0070] In the description of this specification, references to terms such as "some embodiments," "other embodiments," etc., indicate that a specific feature, structure, material, or characteristic described in connection with that embodiment or example is included in at least one embodiment or example of the present invention. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples.

[0071] The above description is only a preferred embodiment of the present invention. For those skilled in the art, there will be changes in the specific implementation and application scope based on the ideas of the present invention. The content of this specification should not be construed as a limitation of the present invention.

Claims

1. A well-drainage device, characterized in that, include: The first milling column (1) has a first cutting outer diameter; The second milling column (2) is connected to the first milling column (1). The second cutting outer diameter of the second milling column (2) is adjustable. The first cutting outer diameter falls within the adjustment range of the second cutting outer diameter. During operation, the second milling column follows the first milling column into the oil well and continues to cut downward. The second milling post (2) includes: a body (21), which is connected to the first milling post (1); Multiple cutting elements (22) are movably disposed within the main body (21); The second milling column (2) also includes a pusher (23), which is inserted into the main body (21). One end of the plurality of cutting elements (22) abuts against the pusher (23). When the pusher (23) moves along the axial direction of the main body (21), it can push the plurality of cutting elements (22) to extend out of the main body (21) respectively. The second milling column (2) also includes a stop mechanism (24), which is located inside the main body (21) and abuts against the end of the pusher (23). When the stop mechanism (24) is subjected to pressure, it can disengage from the main body (21) so that the pusher (23) can move relative to the main body (21). The second milling column (2) also includes a stop member (25), which is provided on the inner wall of the main body (21) and is used to restrict the pusher (23) from moving unidirectionally along the axial direction of the main body (21).

2. The well-drainage device according to claim 1, characterized in that, The multiple cutting elements (22) are divided into multiple cutting groups, which are distributed at intervals on the outer peripheral wall of the main body (21). Each cutting group includes multiple cutting elements (22) arranged at intervals along the spiral direction of the main body (21).

3. The well-drainage device according to claim 1, characterized in that, The pusher (23) is provided with multiple conical sections (231), and the ends of the multiple cutting parts (22) are provided with oblique mating surfaces (221), which are adapted to the conical sections (231).

4. The well-drainage device according to claim 1, characterized in that, The cutting element (22) includes: The cutting part (222) has one end abutting against the pusher (23); A limiting part (223) is provided to restrict the cutting part (222) from disengaging from the main body (21).

5. The well-drainage device according to claim 4, characterized in that, The cutting part (22) further includes a retaining part (224) disposed within the cutting part (222) and used to retain the cutting part (222) within the body (21).

6. The well-drainage device according to claim 1, characterized in that, The well-drainage device also includes a connector (3), the two ends of which are connected to the first milling column (1) and the second milling column (2) respectively, and the outer diameter of the connector (3) is smaller than the first cutting outer diameter.

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