A drill rod

Abstract

The present invention discloses a drill rod, which belongs to the field of oil drilling technology and includes: a first shell; a ball socket; a ball head, one end of which is sleeved in the ball socket, a housing space being defined between the outer side of the ball head and the inner side of the ball socket, a first housing cavity of the first shell, an inner cavity of the ball socket, and an inner cavity of the ball head being sequentially connected to form a main flow channel, and an adjustment hole being defined in the side wall of the ball head; an adjustment ring sleeved on the outer periphery of the ball head and located in the housing space, drilling fluid in the main flow channel can enter the housing space through the adjustment hole and push the first end of the adjustment ring in a first direction, the second end of the adjustment ring being provided with a wedged outer conical surface; a second shell, a first end of the second shell being provided with a rotating spherical surface that is rotatably abutted against the other end of the ball socket, an inner conical surface being provided on the inner side of the first end of the second shell, the wedged outer conical surface being able to be pushed to the wedged inner conical surface to limit the relative rotation of the rotating spherical surface and the ball socket. The present invention can switch between a flexible state and a rigid state.

Description

Technical Field

[0001] The present invention relates to the technical field of oil drilling, in particular to a drill rod. Background Art

[0002] Flexible drill pipe sidetracking is a common technique used in existing wellbore sidetracking technologies. With its excellent directional performance, large wellbore diameter, and low cost, flexible drill pipe sidetracking is ideal for precisely tapping the remaining oil potential in mature oilfields.

[0003] However, the flexible drill pipe has too much deflection near the drill bit and insufficient guidance. The wellbore trajectory drilled in the horizontal section has large fluctuations in inclination and azimuth, and poor stability. Summary of the Invention

[0004] The object of the present invention is to provide a drill rod which can be switched between a flexible state and a rigid state, and can be switched to the rigid state when drilling a horizontal section, and has good guiding performance.

[0005] As conceived above, the technical solution adopted by the present invention is:

[0006] A drill pipe, comprising:

[0007] A first housing is provided with a first accommodating cavity with openings at both ends;

[0008] a ball socket, one end of which is sleeved in the first accommodating cavity and the other end of which extends out of the first accommodating cavity;

[0009] A ball head, one end of which is sleeved in the ball socket, an accommodating space being defined between an outer side surface of the ball head and an inner side surface of the ball socket, the first accommodating cavity of the first housing, the inner cavity of the ball socket, and the inner cavity of the ball head being sequentially connected to form a main flow channel, and an adjustment hole being defined in a side wall of the ball head, the adjustment hole communicating with the main flow channel and the accommodating space;

[0010] an adjusting ring, sleeved on the outer circumference of the ball head and located in the accommodating space, the outer side surface of the adjusting ring being arranged opposite to the inner side surface of the ball socket, the drilling fluid in the main channel being able to enter the accommodating space through the adjusting hole and push the first end of the adjusting ring in a first direction, and the second end of the adjusting ring being provided with a wedging outer conical surface;

[0011] The second shell is provided with a second accommodating cavity with openings at both ends, and the other end of the ball head extends into the second accommodating cavity. The first end of the second shell is provided with a rotating spherical surface, and the rotating spherical surface is rotatably abutted against the other end of the ball head. The inner side of the first end of the second shell is provided with an inner conical surface, and the wedged outer conical surface can be pushed to wedge into the inner conical surface to limit the relative rotation of the rotating spherical surface and the ball head, and make the second shell and the ball head coaxially straight.

[0012] Optionally, the adjustment ring is an integrally formed structure, comprising:

[0013] An adjusting ring body is sleeved on the outer periphery of the ball head;

[0014] an end limiting flange, sleeved on the outer circumference of the ball head and coaxially arranged on one end of the adjusting ring body, wherein the drilling fluid in the main flow channel can enter the accommodating space through the adjusting hole and push the end limiting flange along the first direction, the outer side of the end limiting flange is in sliding contact with the inner side surface of the ball socket, and the inner side surface of the end limiting flange is in sliding contact with the outer side surface of the ball head;

[0015] The tail cone portion is sleeved on the outer periphery of the ball head and coaxially arranged on the other end of the adjustment ring body, and the wedged outer cone surface is arranged on the outer side surface of the tail cone portion.

[0016] Optionally, a tangent cone surface is further provided at the end of the tail cone portion, the cone angle of the tangent cone surface is greater than the cone angle of the wedged outer cone surface, and when the second shell bends relative to the ball head, the tangent cone surface is tangent to the inner surface of the second shell.

[0017] Optionally, the drill rod further includes a retaining ring, which is sleeved in the other end of the ball socket, an outer spherical surface is provided on the outer side of the first end of the second shell, and an inner spherical surface is provided on the inner side of the retaining ring for rotatable contact with the outer spherical surface.

[0018] Optionally, the drill rod also includes an elastic reset member, which is located in the accommodating space and is sleeved on the outer circumference of the adjustment ring body, one end of the elastic reset member abuts against the end limit flange, and the other end of the elastic reset member abuts against the end face of the retaining ring.

[0019] Optionally, a first sealing ring accommodating groove is provided on the outer side of the end limit flange, a first sealing ring is provided in the first sealing ring accommodating groove, and the outer side of the first sealing ring is in sliding contact with the inner side surface of the ball socket.

[0020] Optionally, a second sealing ring accommodating groove is provided on the inner side of the end limiting flange, a second sealing ring is provided in the second sealing ring accommodating groove, and the inner side of the second sealing ring is in sliding contact with the outer side surface of the ball head.

[0021] Optionally, a first filter valve is provided in the regulating hole.

[0022] Optionally, a plurality of adjustment holes are provided at intervals on the side wall of the ball head.

[0023] Optionally, an auxiliary adjustment hole communicating with the accommodating space is provided on the side wall of the ball socket.

[0024] The drill rod proposed by the present invention has a second outer shell that can rotate and abut relative to the ball head when no drilling fluid is circulating in the main channel, thereby making the drill rod flexible and usable as a flexible drill rod. When drilling fluid enters the main channel along a first direction, the drilling fluid in the main channel enters the accommodating space through the adjustment hole and pushes the first end of the adjustment ring along the first direction, thereby pushing the adjustment ring toward the second outer shell until the wedged outer conical surface is pushed to the wedged inner conical surface, thereby limiting the relative rotation of the rotating spherical surface and the ball head. At this time, the second outer shell can no longer rotate relative to the ball head, that is, the second outer shell is in a straight state. At this time, the drill rod is in a rigid state and can be used as a rigid drill rod. It has good rigidity and can improve the accuracy of the wellbore trajectory and the drilling target hit rate. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the following briefly introduces the drawings required for use in describing the embodiments of the present invention. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on the contents of the embodiments of the present invention and these drawings without any creative work.

[0026] Figure 1 is a schematic diagram of a drill rod provided by an embodiment of the present invention;

[0027] Figure 2 yes Figure 1 Schematic diagram of part of the structure;

[0028] Figure 3 yes Figure 2 Schematic diagram of part of the structure;

[0029] Figure 4 is a schematic structural diagram of an adjustment ring provided by an embodiment of the present invention;

[0030] Figure 5 It is a structural schematic diagram of the second shell provided by an embodiment of the present invention.

[0031] In the picture:

[0032] 1. First shell;

[0033] 2. Ball socket; 21. Auxiliary adjustment hole; 211. Second filter valve;

[0034] 3. Ball head; 31. Adjustment hole; 311. First filter valve;

[0035] 4. Adjustment ring; 41. Wedge-in outer conical surface; 42. End limit flange; 421. First sealing ring accommodating groove; 422. Second sealing ring accommodating groove; 43. Adjustment ring body; 44. Tail cone; 45. Tangent conical surface;

[0036] 5. Main stream;

[0037] 6. Second outer shell; 61. Inner conical surface; 611. First inner conical surface; 612. Second inner conical surface;

[0038] 7. Accommodating space; 71. Elastic reset member;

[0039] 8. Retaining ring;

[0040] 91. Male joint of drill pipe; 92. Female joint of drill pipe. DETAILED DESCRIPTION

[0041] To make the technical problems solved by the present invention, the technical solutions adopted, and the technical effects achieved more clearly, the technical solutions of the present invention are further described below with reference to the accompanying drawings and through specific embodiments. It should be understood that the specific embodiments described herein are merely for the purpose of explaining the present invention and are not intended to limit the present invention. It should also be noted that, for ease of description, the drawings only show portions relevant to the present invention, not all of them.

[0042] In the description of the present invention, it should be noted that the terms "center," "up," "down," "left," "right," "vertical," "horizontal," "inside," and "outside" and the like, indicating orientations or positional relationships, are based on the orientations or positional relationships shown in the accompanying drawings and are intended only to facilitate the description of the present invention and simplify the description. They do not indicate or imply that the devices or components referred to must have a specific orientation, be constructed, or operate in a specific orientation. Therefore, they should not be construed as limitations on the present invention. Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance. The terms "first position" and "second position" refer to two different positions.

[0043] In the description of the present invention, it should be noted that, unless otherwise expressly specified or limited, the terms "mounted," "connected," and "connected" should be understood broadly. For example, they may refer to fixed or detachable connections; mechanical or electrical connections; direct or indirect connections through an intermediary; and internal communication between two components. Those skilled in the art will understand the specific meanings of the above terms in the present invention.

[0044] Flexible drill pipe sidetracking is a common technique for sidetracking old wells in existing technologies. It offers excellent directional performance, a large borehole diameter, and low cost, making it ideal for precisely tapping the remaining oil potential in mature oilfields. However, because the curvature radius of the inclination section of flexible drill pipe sidetracking is typically 2m-4m, conventional measurement while drilling (MWD) tools are too large to pass through, making conventional MWD correction impossible. Consequently, the resulting wellbore trajectory is uncontrollable and subject to significant errors. The fundamental reason for this is that the flexible drill pipe exhibits excessive near-bit deflection, resulting in insufficient directional properties. Consequently, the wellbore trajectory drilled in the horizontal section experiences significant fluctuations in inclination and azimuth, resulting in poor stability.

[0045] To solve the above problems, see Figure 1-Figure 5 This embodiment provides a drill rod that can be switched between a rigid state and a flexible state as needed, thereby being able to adapt to different working conditions. When switched to the rigid state, it has good guidance performance.

[0046] Specifically, in this embodiment, the drill rod includes a first housing 1 , a ball socket 2 , a ball head 3 , an adjustment ring 4 and a second housing 6 .

[0047] A first accommodating cavity with openings at both ends is provided in the first housing 1 ; one end of the ball socket 2 is sleeved in the first accommodating cavity, and the other end extends out of the first accommodating cavity.

[0048] One end of the ball head 3 is sleeved in the ball socket 2. There is an accommodating space 7 between the outer side surface of the ball head 3 and the inner side surface of the ball socket 2. The first accommodating cavity of the first shell 1, the inner cavity of the ball socket 2 and the inner cavity of the ball head 3 are connected in sequence to form a main channel 5. An adjustment hole 31 is opened on the side wall of the ball head 3, and the adjustment hole 31 connects the main channel 5 and the accommodating space 7.

[0049] The adjusting ring 4 is sleeved on the outer periphery of the ball head 3 and is located in the accommodating space 7. The outer surface of the adjusting ring 4 is arranged opposite to the inner surface of the ball socket 2. The drilling fluid in the main channel 5 can enter the accommodating space 7 through the adjusting hole 31 and push the first end of the adjusting ring 4 along the first direction. The second end of the adjusting ring 4 is provided with a wedged outer conical surface 41.

[0050] A second accommodating cavity with openings at both ends is provided in the second shell 6, and the other end of the ball head 3 extends into the second accommodating cavity. A rotating spherical surface is provided at the first end of the second shell 6, and the rotating spherical surface and the other end of the ball head 3 are rotatably abutted. An inner conical surface 61 is provided on the inner side of the first end of the second shell 6; the wedged outer conical surface 41 can be pushed to the wedged inner conical surface 61 to limit the relative rotation of the rotating spherical surface and the ball head 3, and make the second shell 6 and the ball head 3 coaxially straight.

[0051] The drill rod provided in this embodiment, when no drilling fluid circulates in the main channel 5, the second shell 6 can rotate and abut relative to the ball socket 2 connected to the first shell 1, thereby making the drill rod flexible and usable as a flexible drill rod. When drilling fluid enters the main channel 5 along the first direction, the drilling fluid in the main channel 5 enters the accommodating space 7 through the adjustment hole 31 and pushes the first end of the adjustment ring 4 along the first direction, thereby pushing the adjustment ring 4 toward the second shell 6 until the wedged outer conical surface 41 is pushed to the wedged inner conical surface 61, thereby limiting the relative rotation of the rotating spherical surface and the ball socket 2. At this time, the second shell 6 can no longer rotate relative to the ball socket 2, that is, the second shell 6 is in a straight state. At this time, the drill rod is rigid and can be used as a rigid drill rod, with good rigidity, which can improve the accuracy of the wellbore trajectory and the drilling target rate.

[0052] Specifically, the main flow channel 5 runs from the head end of the drill rod to the tail end of the drill rod.

[0053] Specifically, in this embodiment, the second housing 6 has the same structure as the first housing 1 .

[0054] Specifically, in this embodiment, the ball socket 2, ball head 3, adjustment ring 4 and second shell 6 constitute an adjustment segment, and another adjustment segment is set at one end of the adjustment segment close to the adjustment ring 4. Multiple adjustment segments are set in sequence to achieve the length adjustment of the drill rod.

[0055] Preferably, a first filter valve 311 is provided in the regulating hole 31; specifically, the first filter valve 311 is threadedly assembled in the regulating hole 31. By providing the first filter valve 311 in the regulating hole 31, large particles of the circulating mud can be filtered, preventing large particles of mud from entering the accommodating space 7 and blocking the regulating ring 4.

[0056] A plurality of adjustment holes 31 are spaced apart on the side wall of the ball head 3 .

[0057] Furthermore, an auxiliary adjustment hole 21 is provided on the side wall of the socket 2, communicating with the accommodating space 7. Preferably, at least two auxiliary adjustment holes 21 are provided along the circumference of the side wall of the socket 2, each of which is provided with a second filter valve 211. Specifically, the second filter valve 211 is threadedly assembled into the auxiliary adjustment hole 21. The second filter valve 211 prevents large particles in the slurry from entering the accommodating space 7.

[0058] Specifically, in this embodiment, the adjustment ring 4 is an integrally formed structure and includes an adjustment ring body 43 , an end limiting flange 42 and a tail cone 44 .

[0059] The adjusting ring body 43 is sleeved on the outer periphery of the ball head 3 .

[0060] The end limit flange 42 is sleeved on the outer periphery of the ball head 3 and coaxially arranged on one end of the adjustment ring body 43. The drilling fluid in the main channel 5 can enter the accommodating space 7 through the adjustment hole 31 and push the end limit flange 42 along the first direction. The outer side of the end limit flange 42 slides and abuts against the inner side surface of the ball socket 2, and the inner side surface of the end limit flange 42 slides and abuts against the outer side surface of the ball head 3.

[0061] The tail cone portion 44 is sleeved on the outer periphery of the ball head 3 and coaxially arranged on the other end of the adjustment ring body 43 . The wedged outer cone surface 41 is arranged on the outer side surface of the tail cone portion 44 .

[0062] Specifically, the gap between the adjustment ring body 43 and the inner surface of the ball socket 2 is 6 mm.

[0063] Furthermore, in this embodiment, the drill rod also includes a retaining ring 8, which is sleeved in the other end of the ball socket 2. The outer side of the first end of the second shell 6 is provided with an outer spherical surface, and the inner side of the retaining ring 8 is provided with an inner spherical surface that can rotatably abut against the outer spherical surface.

[0064] Preferably, in this embodiment, the inner spherical surface of the retaining ring 8 is provided with three grooves for storing lubricating oil and particles that accidentally enter, which helps to facilitate sliding lubrication of the spherical surface.

[0065] Furthermore, in order to help the adjustment ring 4 reset, in this embodiment, the drill rod also includes an elastic reset member 71 (not shown in the figure), which is located in the accommodating space 7 and is sleeved on the outer periphery of the adjustment ring body 43. One end of the elastic reset member 71 abuts against the end limit flange 42, and the other end of the elastic reset member 71 abuts against the end face of the retaining ring 8.

[0066] Optionally, in this embodiment, the elastic return member 71 is a wave spring.

[0067] Furthermore, in this embodiment, a first sealing ring accommodating groove 421 is provided on the outer side of the end limiting flange 42 , a first sealing ring is provided in the first sealing ring accommodating groove 421 , and the outer side of the first sealing ring is in sliding contact with the inner side surface of the ball socket 2 .

[0068] Furthermore, a second sealing ring accommodating groove 422 is provided on the inner side of the end limiting flange 42 , and a second sealing ring is provided in the second sealing ring accommodating groove 422 . The inner side of the second sealing ring is in sliding contact with the outer side surface of the ball head 3 .

[0069] A first sealing ring is provided to form a sealing surface between the adjustment ring 4 and the ball socket 2; a second sealing ring is provided to form a sealing surface between the adjustment ring 4 and the ball head 3. Specifically, in this embodiment, the first sealing ring and the second sealing ring are both O-rings.

[0070] Furthermore, in this embodiment, a tangent cone surface 45 is further provided at the end of the tail cone portion 44 . The tangent cone surface 45 is provided on a side of the wedged outer cone surface 41 away from the adjustment ring body 43 .

[0071] The cone angle of the tangential conical surface 45 is greater than the cone angle of the wedged outer conical surface 41. When the second housing 6 is bent relative to the ball head 3, the tangential conical surface 45 is tangent to the inner surface of the second housing 6. Specifically, when the drill rod is in an extreme bending or buckling state, the tangential conical surface 45 is tangent to the inner surface of the second housing 6.

[0072] Specifically, the inner conical surface 61 of the second outer shell 6 includes a first inner conical surface 611 and a second inner conical surface 612. The first inner conical surface 611 is arranged close to the end, wedged into the outer conical surface 41 and matched with the second inner conical surface 612, and the tangent conical surface 45 is matched with the first inner conical surface 611. The conical hole of the first inner conical surface 611 is larger than the conical hole of the second inner conical surface 612.

[0073] Specifically, in this embodiment, the drill pipe further includes a drill pipe male connector 91, which is connected to the first housing 1. The inner diameter of the drill pipe male connector 91 is smaller than the inner diameter of the first housing 1 and also smaller than the inner diameter of the adjustment section. The drill pipe male connector 91 is located at the head end of the drill pipe, and a drill pipe female connector 92 is also provided at the end of the drill pipe.

[0074] by Figure 3 Taking the illustrated position as an example, during the drilling process, the drilling fluid circulates, and due to the reduced diameter of the drill pipe inner bore, a throttling pressure differential is generated. This throttling pressure differential acts on the end surface of the end limit flange 42 of the adjusting ring 4 within the accommodating space 7 through the adjusting hole 31 and the first filter valve 311, pushing the adjusting ring 4 to the right. Under the action of the hydraulic pressure, the tangential conical surface 45 of the tail cone 44 of the adjusting ring 4 and the wedging outer conical surface 41 sequentially wedge into the inner conical surface 61 of the second outer shell 6 until the adjusting ring 4 is squeezed to the extreme right position. The wedging outer conical surface 41 fully mates with the second inner conical surface 612 of the inner conical surface 61, locking the second outer shell and the ball head 3 so that they are coaxially straight and cannot rotate relative to each other, straightening the drill pipe and making it rigid. At this point, the drill pipe can be used as a rigid drill pipe.

[0075] Specifically, when drilling fluid is circulating and the drill pipe is rigid, the wave spring is in a semi-compressed state. The wave spring's compressive force is much smaller than the force exerted by the throttle pressure differential on the adjusting ring 4, but is greater than the friction between the adjusting ring 4, the ball socket 2, and the ball head 3. When drilling fluid circulation ceases, the throttle pressure differential disappears, and the hydraulic pressure on the left side of the adjusting ring 4 dissipates, causing the wave spring to push the adjusting ring 4 back to the left position.

[0076] The drill pipe provided in this embodiment is directly connected to the drill bit at its head end during use, enabling drilling of the horizontal section of ultra-short-radius sidetracking horizontal wells. Without drilling fluid circulation, the drill pipe becomes flexible, enabling smooth passage through ultra-short-radius wellbores. With circulation, the pipe straightens to become rigid, effectively increasing drill pipe stiffness, improving wellbore trajectory accuracy, and boosting the on-target drilling rate.

[0077] The above embodiments merely illustrate the basic principles and features of the present invention. The present invention is not limited to the above embodiments. Various changes and modifications may be made to the present invention without departing from the spirit and scope of the present invention. Such changes and modifications are intended to fall within the scope of the present invention. The scope of protection claimed in the present invention is defined by the appended claims and their equivalents.

Claims

1. A drill pipe, characterized in that: include: A first housing (1) is provided with a first accommodating cavity with openings at both ends; A ball socket (2), one end of which is sleeved in the first accommodating cavity and the other end of which extends out of the first accommodating cavity; A ball head (3) is sleeved at one end in the ball socket (2); an accommodating space (7) exists between the outer side surface of the ball head (3) and the inner side surface of the ball socket (2); the first accommodating cavity of the first housing (1), the inner cavity of the ball socket (2), and the inner cavity of the ball head (3) are sequentially connected to form a main channel (5); an adjusting hole (31) is provided on the side wall of the ball head (3); the adjusting hole (31) communicates with the main channel (5) and the accommodating space (7); An adjusting ring (4) is sleeved on the outer periphery of the ball head (3) and is located in the accommodating space (7); the outer side surface of the adjusting ring (4) is arranged opposite to the inner side surface of the ball socket (2); the drilling fluid in the main channel (5) can enter the accommodating space (7) through the adjusting hole (31) and push the first end of the adjusting ring (4) in a first direction; the second end of the adjusting ring (4) is provided with a wedging outer conical surface (41); A second housing (6) is provided with a second accommodating cavity with openings at both ends, the other end of the ball head (3) extends into the second accommodating cavity, a rotating spherical surface is provided at the first end of the second housing (6), and the rotating spherical surface is rotatably abutted against the other end of the ball head (3), and an inner conical surface (61) is provided on the inner side of the first end of the second housing (6); the wedged outer conical surface (41) can be pushed to wedge into the inner conical surface (61) to limit the relative rotation of the rotating spherical surface and the ball head (3), and to straighten the second housing (6) and the ball head (3) coaxially; A first filter valve (311) is provided in the regulating hole (31).

2. The drill rod according to claim 1, characterized in that The adjusting ring (4) is an integrally formed structure, comprising: An adjusting ring body (43) is sleeved on the outer periphery of the ball head (3); An end limiting flange (42) is sleeved on the outer periphery of the ball head (3) and coaxially arranged at one end of the adjusting ring body (43), and the drilling fluid in the main channel (5) can enter the accommodating space (7) through the adjusting hole (31) and push the end limiting flange (42) along the first direction, and the outer side of the end limiting flange (42) is in sliding contact with the inner side surface of the ball socket (2), and the inner side surface of the end limiting flange (42) is in sliding contact with the outer side surface of the ball head (3); The tail cone portion (44) is sleeved on the outer periphery of the ball head (3) and coaxially arranged on the other end of the adjustment ring body (43); the wedged outer cone surface (41) is arranged on the outer side surface of the tail cone portion (44).

3. The drill rod according to claim 2, characterized in that The end of the tail cone portion (44) is further provided with a tangent cone surface (45), the cone angle of the tangent cone surface (45) being greater than the cone angle of the wedged outer cone surface (41), and when the second shell (6) is bent relative to the ball head (3), the tangent cone surface (45) is tangent to the inner surface of the second shell (6).

4. The drill rod according to claim 2, characterized in that The drill rod further comprises a retaining ring (8), which is sleeved inside the other end of the ball socket (2); an outer spherical surface is provided on the outer side of the first end of the second shell (6); and an inner spherical surface is provided on the inner side of the retaining ring (8) and is rotatably in contact with the outer spherical surface.

5. The drill rod according to claim 4, characterized in that The drill rod further includes an elastic reset member (71), which is located in the accommodating space (7) and sleeved on the outer periphery of the adjusting ring body (43), one end of the elastic reset member (71) abuts against the end limit flange (42), and the other end of the elastic reset member (71) abuts against the end surface of the retaining ring (8).

6. The drill rod according to claim 2, characterized in that A first sealing ring accommodating groove (421) is provided on the outer side of the end limiting flange (42), a first sealing ring is provided in the first sealing ring accommodating groove (421), and the outer side of the first sealing ring is in sliding contact with the inner side surface of the ball socket (2).

7. The drill rod according to claim 2, characterized in that A second sealing ring accommodating groove (422) is provided on the inner side of the end limiting flange (42), a second sealing ring is provided in the second sealing ring accommodating groove (422), and the inner side of the second sealing ring is in sliding contact with the outer side surface of the ball head (3).

8. The drill rod according to any one of claims 1 to 7, characterized in that: A plurality of adjustment holes (31) are provided at intervals on the side wall of the ball head (3).

9. The drill rod according to any one of claims 1 to 7, characterized in that: An auxiliary adjustment hole (21) communicating with the accommodating space (7) is provided on the side wall of the ball socket (2).

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