Sleeve joint with high torsion resistance
By adding an annular anti-torsion step in the middle of the coupling, the nose end is pressed tightly against the anti-torsion step to form a metal seal, which solves the problem of easy damage and insufficient sealing of traditional API 5B standard BC threaded joints in inclined shafts. This achieves high torque resistance and sealing performance, reduces manufacturing costs, and is compatible with conventional joints.
Patent Information
- Application Number
- CN202520526363.2
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2025-03-25
- Publication Date
- 2025-12-19
- Estimated Expiration
- 2035-03-25
AI Technical Summary
Traditional API 5B standard BC threaded fittings are prone to damage in inclined shafts, have insufficient sealing performance, and are incompatible with conventional fittings, resulting in high costs and leakage risks.
An annular anti-torsion step is added to the middle of the coupling, and the nose end is pressed tightly against the anti-torsion step to form a metal seal. Combined with API 5B standard parameters, high torque resistance and sealing performance are achieved.
It improves the torque resistance of the joint, enhances the sealing performance, reduces manufacturing costs, achieves compatible connection with conventional joints, and reduces oilfield extraction costs.
Smart Images
Figure CN223689642U_ABST
Abstract
Description
TECHNICAL FIELD
[0001] The utility model relates to the technical field of casing connection technology of oil drilling, and particularly relates to a high-torsion-resistance casing joint with anti-over-torque and sealing functions based on API 5B standard BC thread, which is especially suitable for high-torque working conditions such as inclined well top drive operations. BACKGROUND
[0002] With the in-depth development of the oil and gas exploration and development industry, oil and gas wells are becoming deeper and geological conditions are becoming more complex. The traditional API 5B standard BC thread joint has the following problems:
[0003] (1) The torque bearing capacity is insufficient, and the thread is prone to damage due to top drive rotation when casing in the inclined well;
[0004] (2) The sealing property of the ordinary buttress thread depends on thread grease, and there is a risk of leakage during long-term use;
[0005] (3) The existing special buckles need to be customized with tools and cutters, which has high manufacturing cost and is incompatible with the conventional API 5B standard BC thread buckles. SUMMARY
[0006] The utility model aims at overcoming the above-mentioned deficiencies of the traditional technology, and provides a high-torsion-resistance casing joint, which adds an annular anti-torque step in the middle of the coupling, thereby improving the torque bearing capacity of the joint. After the pipe and the coupling are screwed together, the nose end is tightly pressed against the anti-torque step, forming a metal sealing band, which greatly improves the sealing capacity of the joint.
[0007] The utility model aims at overcoming the above-mentioned deficiencies of the traditional technology, and provides a high-torsion-resistance casing joint, which adds an annular anti-torque step in the middle of the coupling, thereby improving the torque bearing capacity of the joint. After the pipe and the coupling are screwed together, the nose end is tightly pressed against the anti-torque step, forming a metal sealing band, which greatly improves the sealing capacity of the joint.
[0008] As a further improvement of the above technical solution:
[0009] The depth L1 of the anti-torque step is equal to L2+a, wherein 2.0mm≤a≤7.52mm, and L2 is the length of the buttress casing thread triangle mark 8 corresponding to the specification in the API 5B standard.
[0010] The diameter D1 of the anti-torque step is equal to the inner hole diameter D2 of the pipe nose end.
[0011] The length of the nose end is 1.0mm-7.5mm.
[0012] The width L3 of the anti-torque step satisfies L3+L1*2≥the minimum length of the buttress thread casing coupling in the API 5B standard.
[0013] The anti-torsion step is provided with a tool withdrawal groove on each side.
[0014] Compared with the prior art, the anti-torsion casing joint has the advantages that:
[0015] (1) Anti-over-torsion: the joint will not be damaged when the using torque is about 1.5 times of the normal torque;
[0016] (2) Double sealing: the nose end is tightly pressed against the anti-torsion step after the pipe and the coupling are screwed, so that a metal sealing band is formed, and the joint has a certain end sealing performance, and the main sealing filled with thread grease greatly improves the sealing capacity of the joint;
[0017] (3) Low cost and easy compatibility: the basic parameters of the API 5B standard BC thread are retained, the manufacturing cost can be effectively controlled, and the joint can be connected with the conventional API 5B standard BC thread, which is convenient for use in oil field, realizes mixed operation of new and old buckles, and effectively reduces the oil field exploitation cost.
[0018] The utility model will be further described in connection with the drawings and specific embodiments. DRAWINGS
[0019] Figure 1 It is a structure schematic view of the high anti-torsion casing joint in the utility model embodiment;
[0020] Figure 2 It is a partial enlarged view of A part in the utility model embodiment; Figure 1
[0021] Figure 3 It is a partial enlarged view of B part in the utility model embodiment. Figure 1
[0022] In the drawing, 1 is a coupling, 2 is a pipe, 3 is a coupling internal thread, 4 is a pipe external thread, 5 is a nose end, 6 is a tool withdrawal groove, 7 is an anti-torsion step, and 8 is an offset trapezoidal casing thread triangle mark. DETAILED DESCRIPTION
[0023] The technical scheme in the utility model embodiment will be clearly and completely described in connection with the drawings of the utility model embodiment. Obviously, the described embodiments are only part of the embodiments of the utility model and not all the embodiments. Based on the embodiments in the utility model, all other embodiments obtained by those skilled in the art without creative labor belong to the protection scope of the utility model. EMBODIMENT
[0024] For example, Figures 1-3 As shown, a high torsional resistance coupling joint comprises a coupling 1 and a pipe 2 connected together by screwing, the coupling 1 is internally threaded at both ends, the pipe 2 is externally threaded at the end, the side of the pipe external thread 4 close to the end of the pipe 2 is provided with a nose 5, the length of the nose 5 is 1.0mm-7.5mm, the size of the coupling 1 (coupling outer diameter, length, bore diameter, bearing surface width) and the parameters of the coupling internal thread 3 and the pipe external thread 4 (tooth type, tooth height, number of teeth per inch, taper, pitch, full thread length, total length of the pipe end to the vanishing point, close distance, thread crest diameter, etc.) fully comply with the API 5B standard.
[0025] The inside center of the coupling 1 is provided with an annular torsional resistance step 7, the diameter D1 of the torsional resistance step 7 is equal to or close to the inner hole diameter D2 of the nose 5; the depth L1 of the torsional resistance step 7 is L2+a, wherein 2.0mm≤a≤7.52mm, L2 is the length of the trapezoidal thread triangle mark 8 corresponding to the specification in the API 5B standard.
[0026] The width L3 of the torsional resistance step 7 can be designed and adjusted according to the need of the torsional strength of the joint, and needs to meet L3+L1*2≥the minimum length of the trapezoidal thread coupling in the API 5B standard.
[0027] The two sides of the torsional resistance step 7 are respectively provided with a tool withdrawal groove 6, the diameter and width of the tool withdrawal groove 6 should be able to ensure that the tool is smoothly withdrawn, and the strength of the coupling is ensured. The setting of the tool withdrawal groove 6 can ensure that the tool is easily withdrawn during the joint machining process, avoid the generation of screw tail, ensure the machining precision, ensure the assembly tightness, simplify the machining process and thus reduce the production cost.
[0028] After the coupling 1 and the pipe 2 are machined, the specified torque is selected according to the specification to make up, when the end face of the nose 5 at the end of the pipe 2 is in contact with the end face of the torsional resistance step 7 of the coupling 1 during the final tightening, the high torsional resistance effect is achieved, and the thread damage is prevented; at the same time, the nose 5 at the end of the pipe 2 and the two end faces of the torsional resistance step 7 of the coupling 1 form an interference fit to achieve a sealing effect.
[0029] The above only describes the preferred embodiment of the present application, and does not limit the present application, any modification, equivalent replacement and improvement made within the spirit and principle of the present application shall be included in the protection scope of the present application.
Claims
1. A high torque resistance spool piece, characterized by: The coupling (1) and the pipe (2) are connected together by threads, the inner part of both ends of the coupling (1) is respectively provided with a coupling inner thread (3), the end part of the pipe (2) is provided with a pipe outer thread (4), the side of the pipe outer thread (4) close to the end part of the pipe (2) is provided with a nose end (5), the inner part of the coupling (1) is provided with an annular anti-torque step (7).
2. A high torque spool sub according to claim 1, wherein: The depth L1=L2+a of the anti-torque step (7), wherein 2.0mm≤a≤7.52mm, L2 is the length of the triangular mark 8 of the buttress thread of the corresponding specification in the API 5B standard.
3. A high torque spool sub according to claim 2, wherein: The diameter D1 of the anti-torque step (7) is equal to the inner hole diameter D2 of the pipe nose end (5).
4. A high torque spool sub according to claim 1, wherein: The length of the nose end (5) is 1.0mm-7.5mm.
5. A high torque spool sub according to claim 3, wherein: The width L3 of the anti-torque step (7) satisfies L3+L1*2≥the minimum length of the buttress thread coupling in the API 5B standard.
6. A high torque spool sub according to claim 1, wherein: The two sides of the anti-torque step (7) are respectively provided with a tool withdrawal groove (6).