A joint for resin-based composite geological exploration drill pipes

Abstract

This utility model belongs to the field of joints and discloses a joint for a resin-based composite geological exploration drill pipe. The joint is a male or female joint. The male joint includes a first connecting segment, a second connecting segment, a third connecting segment, a fourth connecting segment, and a fifth connecting segment connected in sequence. The outer surface of the first connecting segment is provided with external threads. The fourth connecting segment is composed of several sub-connecting segments, with adjacent sub-connecting segments staggered around a central axis. The female joint includes a first connecting segment, a second connecting segment, a third connecting segment, a fourth connecting segment, and a fifth connecting segment connected in sequence. The inner surface of the first connecting segment is provided with internal threads. The fourth connecting segment is composed of several sub-connecting segments, with adjacent sub-connecting segments staggered around a central axis. The outer surfaces of the third, fourth, and fifth connecting segments form a mechanical fit or interlocking connection with the outer composite material, enabling the transmission of multiaxial loads while providing a good sealing effect.

Description

Technical Field

[0001] This utility model belongs to the field of joint technology and relates to a joint for a resin-based composite geological exploration drill rod. Background Technology

[0002] Geological exploration drill pipes are crucial equipment for geological resource development. With the increasing development of deep geothermal, deep oil and gas, and coalbed methane resources in my country, traditional steel drill pipes suffer from drawbacks such as heavy weight, poor corrosion resistance, and large radius of curvature, severely restricting drilling efficiency, depth, and directional drilling capabilities. Resin-based fiber-reinforced composite geological exploration drill pipes offer significant advantages: lightweight, high strength, corrosion resistance, and adjustable rigidity. Compared to steel drill pipes, they can reduce weight by more than 60%, effectively reducing the load on the drilling rig hook and significantly improving the drilling capacity of existing equipment. Simultaneously, they can reduce total tripping time by 40%–50%, effectively reducing drilling time and costs. Furthermore, the minimum permissible radius of curvature is reduced from 30m to less than 15m, significantly improving the development capabilities of horizontal wells and extended reach wells.

[0003] However, the length of geological exploration drill pipes is generally controlled between 6 and 12 meters. To achieve the exploration and development of deep geological resources, reliable connections between drill pipes are required via threaded metal joints. During drilling, geological exploration drill pipes must withstand complex and harsh conditions such as tension, compression, torsion, bending, and internal and external pressure. Achieving a reliable connection between the resin-based composite material drill pipe body and the metal joint is crucial to ensuring its functional performance. Existing connection technologies between composite material pipe bodies and metal joints mainly involve mechanical connections or adhesive bonding. Mechanical connections require drilling holes in the composite material pipe body, which is complex, prone to damaging the composite material, and difficult to meet the high-pressure sealing requirements of the drill pipe. Adhesive bonding results in weaker connections between the metal joint and the composite material pipe body, making it difficult to meet the reliable connection requirements under complex mechanical loads such as tension, compression, torsion, bending, and internal and external pressure during geological exploration drilling. Utility Model Content

[0004] The purpose of this invention is to provide a joint for resin-based composite geological exploration drill rods, addressing the shortcomings of the prior art.

[0005] To solve the above technical problems, the present invention adopts the following technical solution: a connector for a resin-based composite geological exploration drill rod, comprising: the connector is a male connector, the male connector comprising a first connecting segment, a second connecting segment, a third connecting segment, a fourth connecting segment and a fifth connecting segment connected in sequence, the outer surface of the first connecting segment is provided with external threads, the fourth connecting segment is composed of a plurality of sub-connecting segments, adjacent two sub-connecting segments are staggered around a central axis, the cross-section of the sub-connecting segments is non-circular for torsional bearing, and the male connector has a through hole.

[0006] Furthermore, the outer surfaces of the third, fourth, and fifth connecting segments are used to wrap the composite material, and the maximum cross-sectional dimension of the fourth connecting segment after wrapping the composite material is less than or equal to the maximum diameter of the second connecting segment.

[0007] Furthermore, the two adjacent sub-connecting segments are staggered around the central axis at 90°, 60° or 45°.

[0008] Furthermore, the joints of the second, third, fourth, and fifth connecting segments are smooth and burr-free; the roughness of the outer surfaces of the third, fourth, and fifth connecting segments is Rz40~Rz70.

[0009] Furthermore, the maximum diameter of the fourth connecting segment near the end of the third connecting segment is smaller than the maximum diameter of the fourth connecting segment near the end of the fifth connecting segment, and the male connector is used for tensile load bearing; the maximum diameter of the fourth connecting segment near the end of the third connecting segment is larger than the minimum diameter of the fourth connecting segment near the end of the fifth connecting segment, and the male connector is used for compressive load bearing.

[0010] Furthermore, the connector is a female connector, which includes a first connecting segment, a second connecting segment, a third connecting segment, a fourth connecting segment, and a fifth connecting segment connected in sequence. The inner surface of the first connecting segment is provided with an internal thread. The fourth connecting segment is composed of several sub-connecting segments, with adjacent sub-connecting segments arranged in a staggered manner around the central axis. The female connector has a through hole inside.

[0011] Furthermore, the outer surfaces of the third, fourth, and fifth connecting segments are used to wrap the composite material, and the maximum cross-sectional dimension of the fourth connecting segment after wrapping the composite material is less than or equal to the maximum diameter of the second connecting segment.

[0012] Furthermore, the two adjacent sub-connecting segments are staggered around the central axis at 90°, 60° or 45°.

[0013] Furthermore, the joints of the second, third, fourth, and fifth connecting segments are smooth and burr-free; the roughness of the outer surfaces of the third, fourth, and fifth connecting segments is Rz40~Rz70.

[0014] Furthermore, the maximum diameter of the fourth connecting segment near the end of the third connecting segment is smaller than the maximum diameter of the fourth connecting segment near the end of the fifth connecting segment, and the female connector is used for tensile bearing; the maximum diameter of the fourth connecting segment near the end of the third connecting segment is larger than the minimum diameter of the fourth connecting segment near the end of the fifth connecting segment, and the female connector is used for compressive bearing.

[0015] Compared with the prior art, the present invention has the following beneficial technical effects:

[0016] This utility model discloses a joint for a resin-based composite geological drilling rod. The joint forms a mechanical fit or interlocking connection with the outer composite material, which can transmit multi-axis loads, including tension, compression, bending, torsion, and internal and external pressure. It also has a good sealing effect, improves the reliability and stability of mechanical load transmission between the joint and the composite material part, and enhances the fatigue resistance of the connection between the composite material part and the metal joint of the resin-based composite geological drilling rod.

[0017] This utility model discloses a joint for a resin-based composite geological drilling rod. The joint and the outer composite material can be molded in one step without subsequent drilling or other mechanical processing, which can greatly simplify the molding process and improve the molding efficiency. Attached Figure Description

[0018] To more clearly illustrate the technical solutions of the embodiments of this utility model, the accompanying drawings used in the embodiments will be briefly introduced below. It should be understood that the following drawings only show some embodiments of this utility model and should not be regarded as a limitation on the scope. For those skilled in the art, other related drawings can be obtained based on these drawings without creative effort.

[0019] Figure 1 This is a schematic diagram of the male connector of a joint for a resin-based composite geological exploration drill rod according to the present invention.

[0020] Figure 2 for Figure 1 Sectional view at point A in the middle;

[0021] Figure 3 for Figure 1 A sectional view at point B of the fourth connecting segment;

[0022] Figure 4 for Figure 1 A sectional view at point C of the fourth connecting segment;

[0023] Figure 5 This is a schematic diagram of the female connector of a joint for a resin-based composite geological exploration drill rod according to the present invention.

[0024] Figure 6 for Figure 5 Sectional view at point A in the middle;

[0025] Figure 7 for Figure 5 A sectional view at point B of the fourth connecting segment;

[0026] Figure 8 for Figure 5 A sectional view at point C of the fourth connecting segment;

[0027] Figure 9 This is a schematic diagram of the structure of the fourth connecting segment in an embodiment of the present invention, in which two adjacent sub-connecting segments are staggered by 60° around the central axis;

[0028] Figure 10 for Figure 9 Side view;

[0029] Figure 11 This is a schematic diagram of the structure of the fourth connecting segment in an embodiment of the present invention, in which two adjacent sub-connecting segments are staggered by 45° around the central axis;

[0030] Figure 12 for Figure 11 Side view.

[0031] Figure label:

[0032] 1-First connecting segment; 2-Second connecting segment; 3-Third connecting segment; 4-Fourth connecting segment; 5-Fifth connecting segment; 6-Through hole. Detailed Implementation

[0033] To enable those skilled in the art to better understand the present invention, the technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings of the embodiments. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort should fall within the protection scope of the present invention.

[0034] It should be noted that the terms "first," "second," etc., in the specification, claims, and accompanying drawings of this utility model are used to distinguish similar objects and are not necessarily used to describe a specific order or sequence. It should be understood that such data can be interchanged where appropriate so that the embodiments of the utility model described herein can be implemented in orders other than those illustrated or described herein. Furthermore, the terms "comprising" and "having," and any variations thereof, such as a process, method, system, product, or apparatus comprising a series of steps or units, are not necessarily limited to those steps or units explicitly listed, but may include other steps or units not explicitly listed or inherent to such processes, methods, products, or apparatus.

[0035] The present invention will now be described in further detail with reference to the accompanying drawings:

[0036] Example 1

[0037] This utility model provides a joint for resin-based composite geological exploration drill pipes, such as... Figure 1As shown, in this embodiment, the joint of the geological exploration drill pipe is a male joint, which consists of a first connecting section 1, a second connecting section 2, a third connecting section 3, a fourth connecting section 4, and a fifth connecting section 5. The first connecting section 1 is a trapezoidal threaded section, the second connecting section 2 is a cylindrical section, the third connecting section 3 is a transition section, the fourth connecting section 4 is a complex curved surface section, and the fifth connecting section 5 is a conical section. The outer surface of the first connecting section 1 is provided with external threads. The first connecting section 1, the second connecting section 2, the third connecting section 3, the fourth connecting section 4, and the fifth connecting section 5 are connected sequentially from left to right, with smooth, burr-free joints and a single integrated structure. The male joint has a hollow structure inside, and the diameter of the hollow areas is all the same, used for conveying drilling fluid in geological exploration drilling. Figure 2 As shown.

[0038] The outer surfaces of the third connecting segment 3, the fourth connecting segment 4, and the fifth connecting segment 5 are used to wrap the composite material. It should be noted that the maximum cross-sectional dimension of the fourth connecting segment 4 after wrapping the composite material is less than or equal to the maximum diameter of the second connecting segment 2.

[0039] The first connecting section 1, the second connecting section 2, the third connecting section 3, the fourth connecting section 4, and the fifth connecting section 5 are made of high-strength steel or high-strength metal materials such as titanium alloys of grade E, grade G, and grade S.

[0040] The fourth connecting segment 4 consists of several sub-connecting segments. The cross-section of each sub-connecting segment is non-circular for torsional bearing. Adjacent sub-connecting segments are staggered around the central axis, forming a complex curved surface with concave and convex shapes, enabling multi-axial load transfer. Through these concave and convex shape features, the joint can mechanically engage or interlock with the externally wrapped composite material portion, allowing for a high-strength connection between the integrated joint and the composite material tube body, thus meeting the requirement of simultaneously bearing complex multi-axial mechanical loads such as tension, compression, torsion, bending, and internal and external pressure.

[0041] If the maximum diameter of the fourth connecting segment 4 near the third connecting segment 3 is smaller than the maximum diameter of the fourth connecting segment 4 near the fifth connecting segment 5, then the male connector is used for tensile load bearing. Figure 4 As shown; if the maximum diameter of the fourth connecting segment 4 near the third connecting segment 3 is greater than the minimum diameter of the fourth connecting segment 4 near the fifth connecting segment 5, then the male connector is used for compression bearing, as shown. Figure 3 As shown.

[0042] To meet the requirements for high-pressure liquid sealing and the technical requirements for composite material molding processes, the outer surfaces of the third connecting section 3, the fourth connecting section 4, and the fifth connecting section 5 need to be roughened by plasma, laser, or sandblasting processes, with a surface roughness of Rz40~Rz70.

[0043] Example 2

[0044] This utility model provides a joint for resin-based composite geological exploration drill pipes, such as... Figure 5 As shown, in this embodiment, the joint of the geological exploration drill pipe is a female joint, which consists of a first connecting section 1, a second connecting section 2, a third connecting section 3, a fourth connecting section 4, and a fifth connecting section 5. The first connecting section 1 is a trapezoidal threaded section, the second connecting section 2 is a cylindrical section, the third connecting section 3 is a transition section, the fourth connecting section 4 is a complex curved surface section, and the fifth connecting section 5 is a conical section. The inner surface of the first connecting section 1 is provided with internal threads. The first connecting section 1, the second connecting section 2, the third connecting section 3, the fourth connecting section 4, and the fifth connecting section 5 are connected sequentially from left to right, with smooth, burr-free joints and an integral structure. The male joint has a hollow structure inside, used for conveying drilling fluid in geological exploration drilling, such as... Figure 6 As shown.

[0045] The outer surfaces of the third connecting segment 3, the fourth connecting segment 4, and the fifth connecting segment 5 are used to wrap the composite material. It should be noted that the maximum cross-sectional dimension of the fourth connecting segment 4 after wrapping the composite material is less than or equal to the maximum diameter of the second connecting segment 2.

[0046] The first connecting section 1, the second connecting section 2, the third connecting section 3, the fourth connecting section 4, and the fifth connecting section 5 are made of high-strength steel or high-strength metal materials such as titanium alloys of grade E, grade G, and grade S.

[0047] The fourth connecting segment 4 consists of several sub-connecting segments. The cross-section of each sub-connecting segment is non-circular for torsional bearing. Adjacent sub-connecting segments are staggered around the central axis, forming a complex curved surface with concave and convex shapes, enabling multi-axial load transfer. Through these concave and convex shape features, the joint can mechanically engage or interlock with the externally wrapped composite material portion, allowing for a high-strength connection between the integrated joint and the composite material tube body, thus meeting the requirement of simultaneously bearing complex multi-axial mechanical loads such as tension, compression, torsion, bending, and internal and external pressure.

[0048] If the maximum diameter of the fourth connecting segment 4 near the third connecting segment 3 is smaller than the maximum diameter of the fourth connecting segment 4 near the fifth connecting segment 5, then the male connector is used for tensile load bearing. Figure 8 As shown; if the maximum diameter of the fourth connecting segment 4 near the third connecting segment 3 is greater than the minimum diameter of the fourth connecting segment 4 near the fifth connecting segment 5, then the male connector is used for compression bearing, as shown. Figure 7 As shown.

[0049] To meet the requirements for high-pressure liquid sealing and the technical requirements for composite material molding processes, the outer surfaces of the third connecting section 3, the fourth connecting section 4, and the fifth connecting section 5 need to be roughened by plasma, laser, or sandblasting processes, with a surface roughness of Rz40~Rz70.

[0050] Example 3

[0051] In this embodiment, the fourth connecting segment 4 is composed of a sub-connecting segment, such as... Figure 3 He Ru Figure 7 The fourth connecting segment 4 has an elliptical outline 4-I-1 on the side closer to the third connecting segment 3 and an elliptical outline 4-I-2 on the side closer to the fifth connecting segment 5. In other words, one end of the sub-connecting segment is an elliptical outline 4-I-1, and the other end is an elliptical outline 4-I-2. The sub-connecting segment is constructed by using the "loft" or "curve group" function of 3D modeling software to form the fourth connecting segment 4 from the elliptical outlines 4-I-1 and 4-I-2. The elliptical outlines 4-I-1 and 4-I-2 have the same geometric dimensions and are arranged with a 90° offset around their central axis.

[0052] Elliptical profiles 4-I-1 and 4-I-2 are arranged with a 90° offset. The major axis diameter of elliptical profile 4-I-1 is larger than the minor axis diameter of elliptical profile 4-I-2, which improves the axial compressive load transmission capacity of the integrated metal joint. The minor axis diameter of elliptical profile 4-I-1 is smaller than the major axis diameter of elliptical profile 4-I-2, and the 90° offset arrangement of elliptical profiles 4-I-1 and 4-I-2 improves the axial tensile load transmission capacity of the integrated metal joint. The fourth connecting segment 4 is formed by the construction of elliptical profiles 4-I-1 and 4-I-2, which has the ability to transmit multiaxial loads simultaneously.

[0053] Example 4

[0054] In this embodiment, the fourth connecting segment 4 is composed of four sub-connecting segments, such as... Figure 9 As shown, one end of the first sub-connecting segment is a three-segment convex continuous curve profile 4-II-1, and the other end is a three-segment convex continuous curve profile 4-II-2. The other end of the second sub-connecting segment is a three-segment convex continuous curve profile 4-II-3, the other end of the third sub-connecting segment is a three-segment convex continuous curve profile 4-II-4, and the other end of the fourth sub-connecting segment is a three-segment convex continuous curve profile 4-II-5. The three-segment convex continuous curve profiles 4-II-1, 4-II-2, 4-II-3, 4-II-4, and 4-II-5 have the same geometric dimensions. Adjacent continuous curve profiles are staggered by 60° around the central axis. The fourth connecting segment 4 is formed by lofting or "curve grouping" in 3D software.

[0055] Among them, the three-segment convex continuous curve profiles 4-II-1, 4-II-2, 4-II-3, 4-II-4, and 4-II-5 can improve the torsional load transmission capacity of the joint. Adjacent three-segment convex continuous curve profiles 4-II-1, 4-II-2, 4-II-3, 4-II-4, and 4-II-5 are arranged with a 60° misalignment around the central axis, forming a dimensional mismatch, such as... Figure 10 As shown, this design enhances the axial compressive and tensile load transfer capacity of the integrated metal joint. The fourth connecting segment 4, formed by five three-segment convex continuous curve profiles, is capable of simultaneously transmitting multiaxial loads.

[0056] Example 5

[0057] In this embodiment, the fourth connecting segment 4 is composed of four sub-connecting segments, such as... Figure 11 As shown, one end of the first sub-connecting segment is a four-segment convex continuous curve profile 4-III-1, and the other end is a four-segment convex continuous curve profile 4-III-2. The other end of the second sub-connecting segment is a four-segment convex continuous curve profile 4-III-3. The other end of the third sub-connecting segment is a four-segment convex continuous curve profile 4-III-4. The other end of the fourth sub-connecting segment is a four-segment convex continuous curve profile 4-III-5. The four-segment convex continuous curve profiles 4-III-1, 4-III-2, 4-III-3, 4-III-4, and 4-III-5 have the same geometric dimensions. Adjacent continuous curve profiles are staggered by 45° around the central axis. The fourth connecting segment 4 is formed by lofting or "curve grouping" in 3D software.

[0058] Four-segment convex continuous curve profiles 4-III-1, 4-III-2, 4-III-3, 4-III-4, and 4-III-5 can improve the torsional load transmission capacity of the joint. Adjacent four-segment convex continuous curve profiles 4-III-1, 4-III-2, 4-III-3, 4-III-4, and 4-III-5 are arranged with a 45° offset around the central axis, as shown below. Figure 12 As shown, the dimensional mismatch can enhance the axial compressive and tensile load transfer capacity of the integrated metal joint.

[0059] Finally, it should be noted that the above embodiments are only used to illustrate the technical solution of this utility model and not to limit it. Although the utility model has been described in detail with reference to the above embodiments, those skilled in the art should understand that modifications or equivalent substitutions can still be made to the specific implementation of this utility model. Any modifications or equivalent substitutions that do not depart from the spirit and scope of this utility model should be covered within the protection scope of the claims of this utility model.

Claims

1. A joint for resin-based composite geological exploration drill pipes, characterized in that: The connector can be a male or female connector; The connector is a male connector, which includes a first connecting segment (1), a second connecting segment (2), a third connecting segment (3), a fourth connecting segment (4), and a fifth connecting segment (5) connected in sequence. The outer surface of the first connecting segment (1) is provided with external threads. The fourth connecting segment (4) is composed of several sub-connecting segments. Two adjacent sub-connecting segments are staggered around the central axis. The cross-section of the sub-connecting segments is non-circular for torsional bearing. The male connector has a through hole (6).

2. The joint for resin-based composite geological exploration drill pipe according to claim 1, characterized in that: The outer surfaces of the third connecting segment (3), the fourth connecting segment (4) and the fifth connecting segment (5) are used to wrap the composite material. The maximum cross-sectional dimension of the fourth connecting segment (4) after wrapping the composite material is less than or equal to the maximum diameter of the second connecting segment (2).

3. The joint for resin-based composite geological exploration drill pipe according to claim 1, characterized in that: The two adjacent sub-connecting segments are staggered around the central axis at 90°, 60° or 45°.

4. The joint for resin-based composite geological exploration drill pipe according to claim 2, characterized in that: The joints of the second connecting segment (2), the third connecting segment (3), the fourth connecting segment (4), and the fifth connecting segment (5) are smooth and burr-free; The surface roughness of the outer surfaces of the third connecting segment (3), the fourth connecting segment (4) and the fifth connecting segment (5) is Rz40~Rz70.

5. The joint for resin-based composite geological exploration drill pipe according to claim 1, characterized in that: The maximum diameter of the fourth connecting segment (4) near the third connecting segment (3) is smaller than the maximum diameter of the fourth connecting segment (4) near the fifth connecting segment (5), and the male connector is used for tensile bearing. The maximum diameter of the fourth connecting segment (4) near the end of the third connecting segment (3) is greater than the minimum diameter of the fourth connecting segment (4) near the end of the fifth connecting segment (5), and the male connector is used for compression bearing.

6. The joint for resin-based composite geological exploration drill pipe according to claim 1, characterized in that: The connector is a female connector, which includes a first connecting segment (1), a second connecting segment (2), a third connecting segment (3), a fourth connecting segment (4), and a fifth connecting segment (5) connected in sequence. The inner surface of the first connecting segment (1) is provided with an internal thread. The fourth connecting segment (4) is composed of several sub-connecting segments. Two adjacent sub-connecting segments are staggered around the central axis. The cross-section of the sub-connecting segments is non-circular for torsional bearing. The female connector has a through hole (6).

7. The joint for resin-based composite geological exploration drill pipe according to claim 6, characterized in that: The outer surfaces of the third connecting segment (3), the fourth connecting segment (4) and the fifth connecting segment (5) are used to wrap the composite material. The maximum cross-sectional dimension of the fourth connecting segment (4) after wrapping the composite material is less than or equal to the maximum diameter of the second connecting segment (2).

8. The joint for resin-based composite geological exploration drill pipe according to claim 6, characterized in that: The two adjacent sub-connecting segments are staggered around the central axis at 90°, 60° or 45°.

9. The joint for resin-based composite geological exploration drill pipe according to claim 7, characterized in that: The joints of the second connecting segment (2), the third connecting segment (3), the fourth connecting segment (4), and the fifth connecting segment (5) are smooth and burr-free; The surface roughness of the outer surfaces of the third connecting segment (3), the fourth connecting segment (4) and the fifth connecting segment (5) is Rz40~Rz70.

10. The joint for resin-based composite geological exploration drill pipe according to claim 6, characterized in that: The maximum diameter of the fourth connecting segment (4) near the third connecting segment (3) is smaller than the maximum diameter of the fourth connecting segment (4) near the fifth connecting segment (5), and the female connector is used for tensile bearing. The maximum diameter of the fourth connecting segment (4) near the end of the third connecting segment (3) is greater than the minimum diameter of the fourth connecting segment (4) near the end of the fifth connecting segment (5), and the female connector is used for compression bearing.

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