A drill pipe plug for highly deviated wells

Abstract

This utility model relates to a drill pipe plug for highly deviated wells, comprising a pressing guide head for docking with a tailpipe plug in the downhole drilling tool. The drill pipe plug further includes a guide cup connected to the bottom end of the pressing guide head and a plug structure connected to the top end of the pressing guide head. The diameter of the guide cup is larger than the diameter of the pressing guide head. The plug structure includes an integrally formed mandrel and a rubber cup assembly. The bottom end of the mandrel is fixedly connected to the top end of the pressing guide head. The rubber cup assembly includes a first rubber cup, a second rubber cup, a third rubber cup, a fourth rubber cup, and a fifth rubber cup, which are sequentially fitted and fixed on the mandrel from bottom to top. The diameter of the first rubber cup is larger than the inner diameter of the downhole drilling tool and smaller than the diameter of the third rubber cup. The diameter of the third rubber cup is smaller than the diameter of the second rubber cup. The diameters of the second, fourth, and fifth rubber cups are all the same.

Description

Technical Field

[0001] This utility model relates to the field of cementing technology in oil and gas engineering, specifically to a drill pipe plug for highly deviated wells. Background Technology

[0002] As my country's oil and gas exploration and development continues to advance into deeper and ultra-deep formations, tailpipe cementing technology has begun to be widely used in highly deviated wells in major oilfields. In the traditional tailpipe cementing process, drill pipe plugs are usually used in conjunction with tailpipe plugs, with their bottom ends connecting to the top ends of the tailpipe plugs to form a sealing and isolation structure. This isolates the cement slurry at the bottom of the tailpipe plugs from the subsequent displacement fluid at the top of the drill pipe plugs.

[0003] However, highly deviated wells typically contain curved sections. When traditional drill pipe plugs pass through these curved sections, the contact area between the plug and the inner wall of the downhole drilling tool exhibits significant uneven stress distribution. This leads to uneven wear of the plug's cup, causing eccentric wear and significantly affecting its sealing performance. Consequently, this results in the mixing of cement slurry and displacement fluid. Furthermore, traditional drill pipe plugs in highly deviated wells are also susceptible to gravity, causing the cup to adhere downwards to the inner wall of the drilling tool, resulting in eccentricity. This can easily lead to jamming when passing through curved sections, significantly increasing the downward resistance of the drill pipe plug. There is a risk of the cup reversing, failing to connect with the tailpipe plug, and even inducing complex downhole accidents, increasing the risks and costs of handling such incidents. Utility Model Content

[0004] In view of the above-mentioned deficiencies of the prior art, the technical problem to be solved by this utility model is to provide a drill pipe plug for highly deviated wells, which can reduce the occurrence of uneven wear and eccentricity of the drill pipe plug, thereby improving the construction quality of tailpipe cementing in highly deviated wells.

[0005] To achieve the above objectives, this utility model provides a drill pipe plug for highly deviated wells, comprising a pressing guide head for docking with the tailpipe plug in the downhole drilling tool. The drill pipe plug further includes a guide cup connected to the bottom end of the pressing guide head and a plug structure connected to the top end of the pressing guide head. The diameter of the guide cup is larger than the diameter of the pressing guide head. The plug structure includes an integrally formed mandrel and a rubber cup assembly. The bottom end of the mandrel is fixedly connected to the top end of the pressing guide head. The rubber cup assembly includes a first rubber cup, a second rubber cup, a third rubber cup, a fourth rubber cup, and a fifth rubber cup, which are sequentially fitted and fixed on the mandrel from bottom to top. The diameter of the first rubber cup is larger than the inner diameter of the downhole drilling tool and smaller than the diameter of the third rubber cup. The diameter of the third rubber cup is smaller than the diameter of the second rubber cup. The diameters of the second, fourth, and fifth rubber cups are all the same.

[0006] Furthermore, the guide cup is threadedly connected to the bottom end of the pressure guide head.

[0007] Furthermore, the guide cup is made of hard rubber.

[0008] Furthermore, the guide cup, the first rubber cup, the second rubber cup, the third rubber cup, the fourth rubber cup, and the fifth rubber cup are all shaped like an inverted frustum, which is larger at the top and smaller at the bottom.

[0009] Furthermore, the first rubber cup, the second rubber cup, the third rubber cup, the fourth rubber cup, and the fifth rubber cup are all made of nitrile rubber.

[0010] As described above, the drill pipe plug for highly deviated wells according to this utility model has the following beneficial effects:

[0011] By incorporating a guide cup, a pressure guide head, and a rubber plug structure, the drill pipe rubber plug can smoothly pass through the curved sections of highly deviated wells. The design is reasonable, the structure is simple, and the performance is reliable. Furthermore, it exhibits low downward resistance and good centering performance in the downhole drilling tools, effectively preventing eccentricity and uneven wear. It also provides excellent sealing and isolation, and its connection with the tailpipe rubber plug effectively isolates cement slurry from drilling fluid. Moreover, it allows for precise control of the length of the cement plug, preventing metering errors from causing the tailpipe to be empty. Attached Figure Description

[0012] Figure 1 This is a schematic diagram of the drill pipe rubber plug in this utility model.

[0013] Explanation of icon numbers

[0014] 1. Pressing guide head, 2. Guide cup, 3. Rubber plug structure, 4. Mandrel, 5. Rubber cup assembly, 501. First rubber cup, 502. Second rubber cup, 503. Third rubber cup, 504. Fourth rubber cup, 505. Fifth rubber cup. Detailed Implementation

[0015] The specific embodiments of this utility model will be further described in detail below with reference to the accompanying drawings. These embodiments are only used to illustrate this utility model and are not intended to limit it.

[0016] In the description of this utility model, it should be noted that the terms "center," "longitudinal," "lateral," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," and "outer," etc., indicating the orientation or positional relationship, are based on the orientation or positional relationship shown in the accompanying drawings and are only for the convenience of describing this utility model and simplifying the description. They 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 on this utility model. In addition, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance.

[0017] In the description of this utility model, it should be noted that, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "joining" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; 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; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in this utility model according to the specific circumstances.

[0018] Furthermore, in the description of this utility model, unless otherwise stated, "a plurality of" means two or more.

[0019] See Figure 1This utility model provides a drill pipe rubber plug for highly deviated wells, including a pressing guide head 1 for docking with the tailpipe rubber plug in the downhole drilling tool. Specifically, the pressing guide head 1 is also provided with a sealing ring for sealing and a retaining spring for positioning. The drill pipe rubber plug also includes a guide cup 2 connected to the bottom end of the pressing guide head 1 and a rubber plug structure 3 connected to the top end of the pressing guide head 1. The diameter of the guide cup 2 is larger than the diameter of the pressing guide head 1. The rubber plug structure 3 includes an integrally formed mandrel 4 and a rubber cup assembly 5. The bottom end of the mandrel 4... The top end of the mandrel 4 is fixedly connected to the top end of the pressure guide head 1. Preferably, the top end of the pressure guide head 1 has a connecting groove, and the bottom end of the mandrel 4 is fixedly connected in the connecting groove. The rubber cup assembly 5 includes a first rubber cup 501, a second rubber cup 502, a third rubber cup 503, a fourth rubber cup 504, and a fifth rubber cup 505, which are sequentially fitted and fixed on the mandrel 4 from bottom to top. The diameter of the first rubber cup 501 is larger than the inner diameter of the downhole drilling tool and smaller than the diameter of the third rubber cup 503. The diameter of the third rubber cup 503 is smaller than the inner diameter of the mandrel 4. Regarding the diameter of the second rubber cup 502, the diameters of the second rubber cup 502, the fourth rubber cup 504, and the fifth rubber cup 505 are all the same. Specifically, the outer peripheral surfaces of the guide cup 2, the first rubber cup 501, the second rubber cup 502, the third rubber cup 503, the fourth rubber cup 504, and the fifth rubber cup 505 can respectively abut against the inner wall of the downhole drilling tool and maintain close contact with the inner wall of the downhole drilling tool. Specifically, the guide cup 2, the first rubber cup 501, and the second rubber cup 502... The diameters of the third rubber cup 503, the fourth rubber cup 504, and the fifth rubber cup 505 can be flexibly set according to the actual inner diameter of the downhole drilling tool. Preferably, the rubber cup group 5 also includes a sixth rubber cup disposed on top of the fifth rubber cup 505. The diameter of the sixth rubber cup is the same as that of the fifth rubber cup 505, which can further extend the friction area with the inner wall of the downhole drilling tool and avoid local stress concentration. Preferably, the mandrel 4 is made of cemented carbide, which has high hardness and impact and vibration resistance.

[0020] The basic working principle of the drill pipe rubber plug for highly deviated wells involved in this utility model is as follows: By setting a guide cup 2, it can connect with the tailpipe rubber plug together with the pressing guide head 1, and guide the drill pipe rubber plug to center during its descent, reducing initial eccentricity and protecting the pressing guide head 1 to a certain extent; by setting a rubber plug structure 3, the mandrel 4 can enhance the connection between the rubber cup assemblies 5 to a certain extent. When the drill pipe rubber plug passes through the curved section of the highly deviated well during its descent, the first rubber cup 501 first contacts the inner wall of the downhole drill string, forming a preliminary seal and initially scraping the cement slurry on the inner wall of the downhole drill string. The second rubber cup 502 has a larger diameter, which can provide stronger radial support force, further correcting positional deviations and playing a more effective role. For good centering effect, the diameter of the third rubber cup 503 is between the first rubber cup 501 and the second rubber cup 502, and its position is between the second rubber cup 502 and the fourth rubber cup 504. Through different diameters and alternating arrangement, the radial force distribution is optimized, further reducing eccentricity and dispersing the contact pressure between the rubber cup assembly 5 and the inner wall of the downhole drill string. At the same time, the rubber cup assembly 5 can play a sealing and scraping role when facing different inner diameters. The fourth rubber cup 504 and the fifth rubber cup 505 can extend the friction area with the inner wall of the downhole drill string, maintain a balanced pressure distribution, reduce uneven wear, and maintain the continuity of the seal; thereby improving its sealing and isolation performance, avoiding jamming, and reducing the risk of downhole accidents.

[0021] See Figure 1 The present invention will be further described below with reference to a specific embodiment:

[0022] In this embodiment, see Figure 1 As a preferred design, the guide cup 2 is threadedly connected to the bottom end of the pressing guide head 1.

[0023] In this embodiment, see Figure 1 As a preferred design, the guide cup 2 is made of hard rubber, which has high hardness and wear resistance, making it easy to guide the drill rod plug to be centered.

[0024] In this embodiment, see Figure 1 As a preferred design, the guide cup 2, the first rubber cup 501, the second rubber cup 502, the third rubber cup 503, the fourth rubber cup 504, and the fifth rubber cup 505 are all designed as inverted frustum shapes, larger at the top and smaller at the bottom. The inclined sides of the inverted frustum shape allow the guide cup 2 and the rubber cup assembly 5 to form a tighter fit with the inner wall of the downhole drilling tool, uniformly transmit external pressure, and maintain a stable shape through their own rigidity and pressure balance, thereby preventing the edges of the guide cup 2 and the rubber cup assembly 5 from turning outward and having better resistance to deformation.

[0025] In this embodiment, see Figure 1 As a preferred design, the first rubber cup 501, the second rubber cup 502, the third rubber cup 503, the fourth rubber cup 504, and the fifth rubber cup 505 are all made of nitrile rubber, which has good wear resistance, tensile strength, and ductility, and can better resist the inner wall of the downhole drilling tool, further improving its sealing performance.

[0026] As can be seen from the above, the drill pipe plug of this utility model for highly deviated wells has the following beneficial effects:

[0027] By setting up a guide cup 2, a pressure guide head 1, and a rubber plug structure 3, the drill pipe rubber plug can smoothly pass through the curved section of a highly deviated well. The design is reasonable, the structure is simple, and the performance is reliable. Furthermore, it has low downward resistance and good centering performance in the downhole drilling tools, which can effectively avoid eccentricity and uneven wear. It has a good sealing and isolation effect, and when connected with the tailpipe rubber plug, it can effectively isolate cement slurry and drilling fluid. It can also accurately control the length of the cement plug and prevent metering errors from causing the tailpipe to be empty.

[0028] In summary, this utility model effectively overcomes the various shortcomings of the prior art and has high industrial application value.

[0029] The above embodiments are merely illustrative of the principles and effects of this utility model and are not intended to limit the scope of this utility model. Any person skilled in the art can modify or alter the above embodiments without departing from the spirit and scope of this utility model. Therefore, all equivalent modifications or alterations made by those skilled in the art without departing from the spirit and technical concept disclosed in this utility model should still be covered by the claims of this utility model.

Claims

1. A drill pipe rubber plug for highly deviated wells, comprising a butt- pressure guide head (1) for interfacing with a tailpipe rubber plug in the downhole drilling tool, characterized in that: The drill pipe rubber plug also includes a guide cup (2) connected to the bottom end of the pressing guide head (1) and a rubber plug structure (3) connected to the top end of the pressing guide head (1). The diameter of the guide cup (2) is larger than the diameter of the pressing guide head (1). The rubber plug structure (3) includes an integrally formed mandrel (4) and a rubber cup assembly (5). The bottom end of the mandrel (4) is fixedly connected to the top end of the pressing guide head (1). The rubber cup assembly (5) includes a first rubber cup that is sequentially fitted and fixed on the mandrel (4) from bottom to top. (501), second rubber cup (502), third rubber cup (503), fourth rubber cup (504), and fifth rubber cup (505). The diameter of the first rubber cup (501) is larger than the inner diameter of the downhole drilling tool and smaller than the diameter of the third rubber cup (503). The diameter of the third rubber cup (503) is smaller than the diameter of the second rubber cup (502). The diameters of the second rubber cup (502), fourth rubber cup (504), and fifth rubber cup (505) are all the same.

2. A drill pipe rubber plug for highly deviated wells according to claim 1, characterized in that: The guide cup (2) is threadedly connected to the bottom end of the pressure guide head (1).

3. A drill pipe rubber plug for highly deviated wells according to claim 1 characterized in that: The guide cup (2) is made of hard rubber, which has high hardness and wear resistance, making it easy to guide the drill rod plug to be centered.

4. The drill pipe rubber plug for highly deviated wells according to claim 1, characterized in that: The guide cup (2), the first rubber cup (501), the second rubber cup (502), the third rubber cup (503), the fourth rubber cup (504), and the fifth rubber cup (505) are all designed with an inverted frustum shape that is larger at the top and smaller at the bottom. The inclined side of the inverted frustum shape allows the guide cup (2) and the rubber cup assembly (5) to form a tighter fit with the inner wall of the downhole drilling tool, uniformly transmit external pressure, and maintain a stable shape through their own rigidity and pressure balance, thereby preventing the edges of the guide cup (2) and the rubber cup assembly (5) from turning outward, and having better resistance to deformation.

5. The drill pipe plug for highly deviated wells according to claim 1, characterized in that: The first rubber cup (501), the second rubber cup (502), the third rubber cup (503), the fourth rubber cup (504), and the fifth rubber cup (505) are all made of nitrile rubber, which has good wear resistance, tensile strength, and ductility, and can better resist the inner wall of the downhole drilling tool, further improving its sealing performance.

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