A drill pipe assembly for oil mining that is easy to salvage after breaking

Abstract

The invention discloses a drill rod assembly for oil production that is easy to salvage after being broken, and belongs to the field of oil production. The drill rod assembly for oil production that is easy to salvage after being broken can realize auxiliary connection of the broken rod shaft to prevent the rod shaft from directly falling off after being broken during work. By installing a retention piece inside a connecting cavity and connecting the connecting piece between the retention pieces installed on two adjacent rod shafts, the inside of each rod shaft can be auxiliary connected. Through the auxiliary connection, the lower broken position can be prevented from falling directly when the rod shaft is broken, and the broken rod shaft can be directly and slowly lifted upward by pulling, which improves the rapidity and convenience of the salvage of the device after being broken to a certain extent, and effectively guarantees the efficiency of oil production.

Description

Technical Field

[0001] The invention relates to the field of oil exploitation, and more particularly to a drill rod assembly for oil exploitation which is convenient for salvaging after being broken. Background Art

[0002] A drill pipe is a steel pipe with threads on both the upper and lower ends. It is usually used to connect the surface equipment of a drilling rig and the drilling and grinding equipment or bottom hole device at the bottom of the well. The connection of the drill pipe can effectively mine underground minerals, so it is widely used in the mining of underground gas and liquid minerals such as petroleum and natural gas.

[0003] Since the drill rod needs to be rotated and pressurized upward during use, it has a certain number of uses. During use, if the construction operation is wrong or affected by the geological environment, it is easy for the drill rod to break due to uneven force during drilling. The broken drill rod is trapped in the borehole formed by drilling. When the drilling position is too deep, the broken drill rod is inconvenient to salvage, affecting the efficiency of oil extraction. In severe cases, it may even lead to the abandonment of the drilling.

[0004] To this end, we propose a drill pipe assembly for oil mining that is easy to salvage after fracture to solve some of the problems existing in the above-mentioned prior art. Summary of the invention

[0005] 1. Technical problems to be solved

[0006] In view of the problems existing in the prior art, the purpose of the present invention is to provide a drill rod assembly for oil production that is easy to salvage after breaking, which can realize auxiliary connection of the broken rod shaft to prevent the rod shaft from falling off directly after breaking during operation. By installing the retention piece inside the connecting cavity and connecting the connecting piece between the retention pieces installed on two adjacent rod shafts, the inside of each rod shaft can be auxiliary connected. Through the auxiliary connection, the lower broken position can be prevented from falling directly when the rod shaft breaks, and the broken rod shaft can be directly and slowly lifted upward by pulling, which improves the speed and convenience of salvaging the device after breaking to a certain extent, and effectively ensures the efficiency of oil production.

[0007] 2. Technical solution

[0008] To solve the above problems, the present invention adopts the following technical solutions.

[0009] A drill pipe assembly for oil mining that is easy to salvage after a break includes a rod body, a connecting sleeve is fixedly welded to the upper end of the rod body, a connecting head is fixedly connected to the lower end of the rod body, a connecting cavity matched with the outer size of the connecting head is provided inside the connecting sleeve, and matching threads are provided on the inner end wall of the connecting cavity and the outer end wall of the connecting head, a retention piece is placed inside the connecting cavity, and the retention piece includes a retention plate mounted on the bottom of the connecting cavity, a shaft sleeve is vertically fixed at the middle position of the retention plate, a plurality of flow holes arranged around the shaft sleeve are evenly provided inside the retention plate, symmetrical hooks are installed on the upper and lower sides of the shaft sleeve, and the hooks are connected to the connecting piece inserted into the rod body.

[0010] Furthermore, the inner dimension of the connecting cavity is larger than the inner dimension of the shaft, and the outer dimension of the retention plate is matched with the inner dimension of the connecting cavity.

[0011] Furthermore, a reinforcement block provided for the truncated cone structure is fixedly installed at the connection between the rod shaft and the connecting sleeve, and a reinforcement block provided for the truncated cone structure is also fixedly installed at the connection between the rod shaft and the connecting head.

[0012] Furthermore, multiple reinforcement blocks 2 fixed to the outer end wall of the sleeve are welded on the upper and lower outer end walls of the retention plate, and the outer shapes of the multiple reinforcement blocks 2 are all set to be a triangular structure.

[0013] Furthermore, an extension rod is installed between each hook and its corresponding shaft sleeve, and the extension rod and the shaft sleeve are rotationally connected, and the hook is fixedly connected to the corresponding extension rod.

[0014] Furthermore, the connecting member includes a steel cable inserted into the rod body, and the upper and lower ends of the steel cable are fixedly connected with connecting rings with a circular ring structure, and the connecting ring is hooked inside a hook adjacent thereto.

[0015] Furthermore, the outer shape of the hook is set to a C-shaped structure, and the interior of the hook is elastically rotatably connected to a shift rod through a torsion spring, and the hook cooperates with the shift rod to form a closed circular ring structure.

[0016] Furthermore, the length of the steel cable is greater than the inner length of the shaft.

[0017] Furthermore, a movable sleeve is connected to the upper outer movable sleeve of the rod body, and the lower end of the movable sleeve is fixedly connected to a guide sleeve that gradually expands outward from top to bottom, and the bottom of the guide sleeve is fixedly connected to a limiting sleeve arranged on the outer side of the rod body, and the outer end wall of the limiting sleeve is evenly equipped with anti-slip wear patterns, and the outer diameter of the limiting sleeve is smaller than the outer diameter of the connecting sleeve.

[0018] Furthermore, a plurality of communication ports are evenly opened on the outer end wall of the guide sleeve, an airbag is filled between the limiting sleeve and the shaft, and the airbag is fixedly connected to the inner end wall of the limiting sleeve, and the lower end of the airbag is exposed outside the limiting sleeve.

[0019] 3. Beneficial effects

[0020] Compared with the prior art, the advantages of the present invention are:

[0021] (1) This solution connects the connecting piece between two adjacent retention pieces, so that after the rod body is broken, the upper and lower broken positions can be auxiliary connected to avoid the direct falling off of the parts below the broken position, which improves the convenience of salvaging the device to a certain extent. At the same time, by installing retention pieces and connecting pieces inside each rod body, the auxiliary connections inside each rod body can be conveniently dispersed to avoid a single connecting piece from bearing too much gravity during salvage, effectively improving the working stability of the device. In addition, by evenly opening a plurality of flow holes inside the retention plate, the smoothness of the connection between the two adjacent rod bodies is effectively guaranteed.

[0022] (2) By setting the inner dimension of the connecting cavity larger than the inner dimension of the rod body, a retention plate that matches the inner dimension of the connecting cavity can be mounted at its bottom, so that the retention piece can be flexibly taken in and out from the inside of the connecting head during installation, thereby improving the convenience of the device during use and assembly. At the same time, by setting the outer dimension of the retention plate to match the inner dimension of the connecting cavity, the retention plate can be effectively clamped and restricted when the upper and lower connecting heads and the connecting sleeve are connected, thereby ensuring the stability of the retention piece inside the connecting cavity after installation.

[0023] (3) By fixing and welding the reinforcing block 1 between the rod body and the connecting sleeve, and between the rod body and the connecting head, the connection firmness between the connecting sleeve, the connecting head and the rod body can be effectively guaranteed. At the same time, by setting the outer shape of the reinforcing block 1 to a truncated cone structure, the connection position can be guided when the device moves up and down, avoiding the accumulation of soil and rock impurities at the connection between the connecting sleeve and the rod body and between the connecting head and the rod body during drilling, which is beneficial to reducing the probability of corrosion damage to the connection between the connecting sleeve, the connecting head and the rod body.

[0024] (4) By fixing and welding a plurality of reinforcing blocks arranged in a triangular structure between the retention plate and the shaft sleeve, the structural stability at the connection position between the retention plate and the shaft sleeve can be effectively improved, the load capacity at the retention plate can be effectively improved, and the probability of stress fracture caused by the flow holes opened inside the retention plate is reduced, which is beneficial to improving the stability of the device during fracture salvage.

[0025] (5) By installing the extension rod between the hook and the sleeve, the distance between the hook and the sleeve can be extended, avoiding the hook being too close to the retention plate, resulting in poor circulation at the retention plate, and effectively ensuring the stability of the upward and downward circulation inside the device. By fixing two connecting rings with circular ring structures at the upper and lower ends of the steel cable, the connecting ring can be placed on the hook with the help of the circular hole in the middle of the connecting ring, which is beneficial to improving the convenience of connection between the connecting piece and the hook.

[0026] (6) By setting the shape of the hook to a C-shaped structure and connecting the lever to the opening on the hook through the elastic rotation of the torsion spring, the opening can be sealed with the elastic support of the torsion spring after the connecting ring is put on the hook to prevent the connecting ring from falling off from the opening, thereby improving the firmness and stability of the connection between the connecting ring and the hook to a certain extent.

[0027] (7) By setting the length of the steel cable to be greater than the inner length of the ear of the shaft, the steel cable can be in a relaxed state and inserted into the interior of the shaft under normal conditions. When the shaft is not broken, the steel cable as a whole will not be subjected to upward and downward pulling forces. This state can provide a certain buffer space for the steel cable when the shaft is broken, thereby preventing the steel cable from being broken synchronously when the shaft is broken, thereby effectively ensuring the working stability of the device.

[0028] (8) By arranging the movable sleeve, the guide sleeve and the limiting sleeve on the outside of the rod body, when the rod body is broken and needs to be pulled upward, the limiting sleeve is relatively moved to the broken position of the rod body with the help of the friction resistance between the limiting sleeve and the inner end wall of the borehole, and the broken position is guided by the sleeve, which can effectively prevent the broken rod body below from being skewed and inserted on the inner end wall of the borehole, effectively ensuring the stability of the salvage device. At the same time, by opening anti-slip wear grooves on the outer end wall of the limiting sleeve, the friction resistance between the limiting sleeve and the inner end wall of the borehole is effectively improved, ensuring the stability of the limiting sleeve moving downward relative to the rod body when the rod body is pulled upward.

[0029] (9) By evenly opening a plurality of connecting ports on the outer end wall of the guide sleeve, the connectivity between the interior of the limiting sleeve and the top can be ensured. When the limiting sleeve is arranged at the broken position of the rod body, it is avoided that the inside of the limiting sleeve is inconvenient to insert the sleeve due to the presence of sludge. By filling the air bag between the limiting sleeve and the rod body, it is avoided that excessive sludge is blocked inside the limiting sleeve when the device drills downward, thereby effectively ensuring the working stability of the device. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] Figure 1 A perspective view of the present invention;

[0031] Figure 2 It is a front view of the present invention;

[0032] Figure 3is a cross-sectional view of the present invention;

[0033] Figure 4 for Figure 3 A front view of

[0034] Figure 5 for Figure 4 The structural diagram at A in the middle;

[0035] Figure 6 A top view of the present invention;

[0036] Figure 7 It is a structural schematic diagram of the retention member and the connecting member of the present invention;

[0037] Figure 8 A three-dimensional diagram of a retention member of the present invention;

[0038] Fig. 9 It is a front view of the retention member of the present invention;

[0039] Fig.10 It is a side view of the retention member of the present invention.

[0040] Description of the numbers in the figure:

[0041] 1. Rod body; 101. Connecting sleeve; 102. Connecting head; 103. Connecting cavity; 104. Reinforcement block one; 2. Retention piece; 201. Retention plate; 202. Bushing; 203. Flow hole; 204. Reinforcement block two; 205. Extension rod; 206. Hook; 3. Connecting piece; 301. Steel cable; 302. Connecting ring; 4. Movable sleeve; 401. Guide sleeve; 402. Limiting sleeve; 403. Anti-skid wear pattern; 404. Connecting port; 405. Airbag. DETAILED DESCRIPTION

[0042] The technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention; it is obvious that the described embodiments are only part of the embodiments of the present invention, rather than all the embodiments, and all other embodiments obtained by ordinary technicians in this field based on the embodiments of the present invention without making creative work are within the scope of protection of the present invention.

[0043] In the description of the present invention, it should be noted that the terms "upper", "lower", "inner", "outer", "top / bottom" and the like indicate positions or positional relationships based on the positions or positional relationships shown in the drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific position, be constructed and operated in a specific position, and therefore cannot be understood as limiting the present invention. In addition, the terms "first" and "second" are used for descriptive purposes only and cannot be understood as indicating or implying relative importance.

[0044] In the description of the present invention, it should be noted that, unless otherwise clearly specified and limited, the terms "installed", "provided with", "mounted / connected", "connected", etc. should be understood in a broad sense. For example, "connected" can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or it can be indirectly connected through an intermediate medium, or it can be the internal communication of two components. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0045] Embodiment 1:

[0046] See also Figure 1-10 A drill pipe assembly for oil mining that is easy to salvage after fracture, including a rod body 1, a connecting sleeve 101 is fixedly welded on the upper end of the rod body 1, and a connecting head 102 is fixedly connected to the lower end of the rod body 1. A connecting cavity 103 that matches the outer size of the connecting head 102 is opened inside the connecting sleeve 101, and the inner end wall of the connecting cavity 103 and the outer end wall of the connecting head 102 are equipped with matching threads. A retention member 2 is placed inside the connecting cavity 103, and the retention member 2 includes a retention plate 201 built on the bottom of the connecting cavity 103, a sleeve 202 is vertically fixed at the middle position of the retention plate 201, and a plurality of flow holes 203 arranged around the sleeve 202 are evenly opened inside the retention plate 201, and symmetrical hooks 206 are installed on the upper and lower sides of the sleeve 202, and the hooks 206 are connected to the connecting member 3 inserted into the rod body 1.

[0047] When the device is working, the staff uses the device to cooperate with the drill bit to perform drilling operations, and uses the threaded connection between the connecting head 102 and the connecting cavity 103 to vertically connect multiple devices in sequence. When connecting, the staff needs to connect the connecting piece 3 inserted into the upper rod shaft 1 with the hook 206 inside the rod shaft 1 below it. When the rod shaft 1 breaks during drilling, the staff slowly lifts the device. Since the connecting piece 3 is connected between the retention pieces 2 installed in two adjacent connecting cavities 103, the broken rod shaft 1 still maintains a certain connection state. The broken rod shaft 1 is slowly lifted upward by pulling, which prevents the rod shaft 1 from falling directly below the broken part after the break, thereby ensuring the quick and convenient salvage of the rod shaft 1 after the break.

[0048] By connecting the connecting piece 3 between two adjacent retention pieces 2, the upper and lower broken positions can be assisted to be connected after the rod shaft 1 is broken, so as to avoid the direct falling off of the parts below the broken position, thereby improving the convenience of salvaging the device to a certain extent. At the same time, by installing retention pieces 2 and connecting pieces 3 inside each rod shaft 1, the auxiliary connections inside each rod shaft 1 can be conveniently dispersed, so as to avoid a single connecting piece 3 bearing too much gravity during salvage, thereby effectively improving the working stability of the device. Moreover, by evenly opening a plurality of flow holes 203 inside the retention plate 201, the smoothness of the connection between the two adjacent rod shafts 1 is effectively guaranteed.

[0049] See also Figure 4-5 The inner dimension of the connecting cavity 103 is larger than the inner dimension of the rod body 1, and the outer dimension of the retention plate 201 is matched with the inner dimension of the connecting cavity 103. When the device is working, by setting the inner dimension of the connecting cavity 103 larger than the inner dimension of the rod body 1, the retention plate 201 matched with the inner dimension of the connecting cavity 103 can be mounted on its bottom, so that the retention member 2 can be flexibly taken and placed from the inside of the connecting head 102 during installation, thereby improving the convenience of the device during use and assembly. At the same time, by setting the outer dimension of the retention plate 201 to be matched with the inner dimension of the connecting cavity 103, the retention plate 201 can be effectively clamped and restricted when the upper and lower connecting heads 102 and the connecting sleeve 101 are connected, thereby ensuring the stability of the retention member 2 in the connecting cavity 103 after the installation is completed.

[0050] See also Figure 5 The connection between the rod body 1 and the connecting sleeve 101 is fixedly installed with a reinforcing block 104 set for the truncated cone structure, and the connection between the rod body 1 and the connecting head 102 is also fixed with a reinforcing block 104 set for the truncated cone structure. When the device is working, by fixing and welding the reinforcing block 104 between the rod body 1 and the connecting sleeve 101, and between the rod body 1 and the connecting head 102, the connection firmness between the connecting sleeve 101, the connecting head 102 and the rod body 1 can be effectively guaranteed. At the same time, by setting the shape of the reinforcing block 104 to a truncated cone structure, the connection position can be guided when the device moves up and down, avoiding the accumulation of soil and stone impurities at the connection between the connecting sleeve 101 and the rod body 1 and the connection between the connecting head 102 and the rod body 1 during drilling, which is beneficial to reducing the probability of corrosion damage to the connection between the connecting sleeve 101, the connecting head 102 and the rod body 1.

[0051] See also Figure 8-10A plurality of reinforcing blocks 204 fixed to the outer end walls of the sleeve 202 are welded on the upper and lower outer end walls of the retention plate 201, and the shapes of the plurality of reinforcing blocks 204 are all set to a triangular structure. When the device is working, the plurality of reinforcing blocks 204 set to a triangular structure are fixedly welded between the retention plate 201 and the sleeve 202, so that the structural stability at the connection position between the retention plate 201 and the sleeve 202 can be effectively improved, and the load capacity of the retention plate 201 can be effectively improved, and the probability of stress fracture caused by the flow hole 203 opened inside the retention plate 201 is reduced, which is conducive to improving the stability of the device during fracture salvage.

[0052] See also Figure 5 and Figure 8 An extension rod 205 is installed between each hook 206 and its corresponding sleeve 202, and the extension rod 205 is rotatably connected to the sleeve 202, and the hook 206 is fixedly connected to its corresponding extension rod 205. When the device is working, by installing the extension rod 205 between the hook 206 and the sleeve 202, the distance between the hook 206 and the sleeve 202 can be extended, avoiding the hook 206 being too close to the retention plate 201, resulting in poor circulation at the retention plate 201, and effectively ensuring the stability of the upward and downward circulation inside the device.

[0053] See also Figure 7 The connecting member 3 includes a steel cable 301 inserted into the rod body 1, and the upper and lower ends of the steel cable 301 are fixedly connected with connecting rings 302 with a circular ring structure, and the connecting ring 302 is hooked inside a hook 206 close thereto. When the device is working, the two connecting rings 302 with circular ring structures are fixedly installed on the upper and lower ends of the steel cable 301. With the help of the circular hole in the middle of the connecting ring 302, the connecting ring 302 can be sleeved on the hook 206, which is beneficial to improving the convenience of connection between the connecting member 3 and the hook 206.

[0054] See also Figure 8-9The outer shape of the hook 206 is set to a C-shaped structure, and the interior of the hook 206 is elastically rotatably connected to a shift rod through a torsion spring. The hook 206 cooperates with the shift rod to form a closed circular ring structure. When the device is working, when the connecting ring 302 needs to be sleeved on the hook 206, the shift rod can be pushed open by pressing. After the connecting ring 302 is sleeved on the hook 206, under the elastic support of the torsion spring, the shift rod closes and blocks the opening opened on the hook 206 to block the opening to prevent the connecting ring 302 from falling off. By setting the outer shape of the hook 206 to a C-shaped structure and elastically rotating the shift rod to the opening on the hook 206 through the torsion spring, with the elastic support of the torsion spring, the opening can be blocked after the connecting ring 302 is sleeved on the hook 206 to prevent the connecting ring 302 from falling off from the opening, thereby improving the firmness and stability of the connection between the connecting ring 302 and the hook 206 to a certain extent.

[0055] See also Figure 3-5 The length of the steel cable 301 is greater than the length inside the shaft 1. When the device is working, by setting the length of the steel cable 301 to be greater than the inner length of the shaft 1, the steel cable 301 can be in a relaxed state and inserted into the shaft 1 under normal conditions. When the shaft 1 is not broken, the steel cable 301 as a whole will not be subjected to upward and downward pulling forces. This state can provide a certain buffer space for the steel cable 301 when the shaft 1 is broken, thereby preventing the steel cable 301 from being broken synchronously when the shaft 1 is broken, thereby effectively ensuring the working stability of the device.

[0056] See also Figure 1-5 The upper outer side of the rod shaft 1 is movably sleeved with a movable sleeve 4, and the lower end of the movable sleeve 4 is fixedly connected with a guide sleeve 401 which gradually expands outward from top to bottom, and the bottom of the guide sleeve 401 is fixedly connected with a limiting sleeve 402 sleeved on the outer side of the rod shaft 1, and the outer end wall of the limiting sleeve 402 is evenly equipped with anti-slip wear grooves 403, and the outer diameter of the limiting sleeve 402 is smaller than the outer diameter of the connecting sleeve 101. When the device is working, when the broken rod shaft 1 is connected with the retention member 2 and the connecting member 3 and pulled upward, the friction resistance between the limiting sleeve 402 and the inner end wall of the drilled hole is used to make the movable sleeve 4, the guide sleeve 401 and the limiting sleeve 402 move upward relatively on the outer side of the rod shaft 1, and the limiting sleeve 402 is sleeved on the broken position of the rod shaft 1 after moving, and the continuity of the broken position of the rod shaft 1 is guaranteed by the restriction of the limiting sleeve 402, so as to prevent the broken rod shaft 1 located below from being obliquely inserted on the inner end wall of the drilled hole during the upward pulling process.

[0057] By movably sleeve-arranging the movable sleeve 4, the guide sleeve 401 and the limiting sleeve 402 on the outside of the rod shaft 1, when the rod shaft 1 is broken and needs to be pulled upward, the limiting sleeve 402 is relatively moved to the broken position of the rod shaft 1 by means of the friction resistance between the limiting sleeve 402 and the inner end wall of the borehole, and the broken position is sleeved and guided, which can effectively prevent the broken rod shaft 1 below from being skewed and inserted on the inner end wall of the borehole, and effectively ensure the stability of the salvage device. At the same time, by opening the anti-slip wear pattern 403 on the outer end wall of the limiting sleeve 402, the friction resistance between the limiting sleeve 402 and the inner end wall of the borehole is effectively improved, thereby ensuring the stability of the limiting sleeve 402 moving downward relative to the rod shaft 1 when the rod shaft 1 is pulled upward.

[0058] See also Figure 1-2 and Figure 5 A plurality of communication ports 404 are evenly provided on the outer end wall of the guide sleeve 401, an air bag 405 is filled between the limiting sleeve 402 and the shaft 1, and the air bag 405 is fixedly connected to the inner end wall of the limiting sleeve 402, and the lower end of the air bag 405 is exposed on the outer side of the limiting sleeve 402. When the device is working, when the limiting sleeve 402 moves downward and is sleeved on the broken position on the shaft 1, the wound at the broken position is punctured, causing the air bag 405 to rupture, and the limiting sleeve 402 is smoothly sleeved on the broken position. By evenly opening multiple connecting ports 404 on the outer end wall of the guide sleeve 401, the connectivity between the interior of the limiting sleeve 402 and the top can be guaranteed. When the limiting sleeve 402 is set on the broken position of the shaft 1, it is avoided that the inside of the limiting sleeve 402 is inconvenient to insert the sleeve due to the presence of sludge. By filling the air bag 405 between the limiting sleeve 402 and the shaft 1, it is possible to avoid excessive sludge clogging the interior of the limiting sleeve 402 when the device drills downward, thereby effectively ensuring the working stability of the device.

[0059] The above is only a preferred specific implementation of the present invention; however, the protection scope of the present invention is not limited thereto. Any technician familiar with the technical field can make equivalent replacements or changes according to the technical solution and its improved conception within the technical scope disclosed by the present invention, which should be covered by the protection scope of the present invention.

Claims

1. A drill pipe assembly for oil mining that facilitates salvage after fracture, comprising a rod body (1), Features: The upper end of the rod body (1) is fixedly welded with a connecting sleeve (101), and the lower end of the rod body (1) is fixedly connected with a connecting head (102). The interior of the connecting sleeve (101) is provided with a connecting cavity (103) that matches the outer dimensions of the connecting head (102), and the inner end wall of the connecting cavity (103) and the outer end wall of the connecting head (102) are both equipped with matching threads. A retention piece (2) is placed inside the connecting cavity (103), and the retention piece (2 ) comprises a retention plate (201) arranged at the bottom of the connection chamber (103), a shaft sleeve (202) being vertically fixed at the middle position of the retention plate (201), a plurality of flow holes (203) being evenly arranged around the shaft sleeve (202) being arranged inside the retention plate (201), symmetrically arranged hooks (206) being installed on both upper and lower sides of the shaft sleeve (202), and a connecting piece (3) inserted into the interior of the rod body (1) being connected to the hook (206); The connecting member (3) comprises a steel cable (301) inserted into the interior of the rod body (1), and the upper and lower ends of the steel cable (301) are fixedly connected to connecting rings (302) of a circular ring structure, the connecting ring (302) is hooked inside a hook (206) adjacent thereto, the hook (206) is configured as a C-shaped structure, the interior of the hook (206) is elastically rotatably connected to a shift lever via a torsion spring, the hook (206) cooperates with the shift lever to form a closed circular ring structure, and the length of the steel cable (301) is greater than the length of the interior of the rod body (1).

2. A drill pipe assembly for oil recovery after fracture according to claim 1, Features: The inner dimension of the connecting cavity (103) is larger than the inner dimension of the shaft (1), and the outer dimension of the retention plate (201) is adapted to the inner dimension of the connecting cavity (103).

3. A drill pipe assembly for oil recovery after fracture according to claim 1, Features: A reinforcing block (104) provided for a truncated cone structure is fixedly mounted at the connection between the shaft (1) and the connecting sleeve (101), and a reinforcing block (104) provided for a truncated cone structure is also fixedly mounted at the connection between the shaft (1) and the connecting head (102).

4. A drill pipe assembly for oil recovery after fracture according to claim 1, Features: A plurality of reinforcing blocks 2 (204) fixed to the outer end wall of the shaft sleeve (202) are welded on the upper and lower outer end walls of the retention plate (201), and the outer shapes of the plurality of reinforcing blocks 2 (204) are all set to be triangular structures.

5. The drill pipe assembly for oil mining that is easy to salvage after fracture according to claim 1, Features: An extension rod (205) is installed between each hook (206) and its corresponding shaft sleeve (202), and the extension rod (205) and the shaft sleeve (202) are rotatably connected, and the hook (206) and its corresponding extension rod (205) are fixedly connected.

6. A drill pipe assembly for oil recovery after fracture according to claim 1, Features: The upper outer side of the shaft (1) is movably sleeved with a movable sleeve (4), and the lower end of the movable sleeve (4) is fixedly connected to a guide sleeve (401) that gradually expands outward from top to bottom, and the bottom of the guide sleeve (401) is fixedly connected to a limiting sleeve (402) sleeved on the outer side of the shaft (1), and the outer end wall of the limiting sleeve (402) is evenly equipped with anti-slip wear patterns (403), and the outer diameter of the limiting sleeve (402) is smaller than the outer diameter of the connecting sleeve (101).

7. A drill pipe assembly for oil recovery after fracture according to claim 6, Features: A plurality of communication openings (404) are evenly arranged on the outer end wall of the guide sleeve (401), an air bag (405) is filled between the limiting sleeve (402) and the shaft (1), and the air bag (405) is fixedly connected to the inner end wall of the limiting sleeve (402), and the lower end of the air bag (405) is exposed outside the limiting sleeve (402).

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