Direct connection type sleeve pipe with anti-rotation locking structure

Abstract

The present application relates to the technical field of downhole tools, and particularly relates to a straight connection type casing with anti-rotation locking structure. The casing is provided with an outer threaded part and an inner threaded part on two sides respectively, an annular bevel is arranged on one side of the casing close to the outer threaded part, the annular bevel is provided with a first notch, an extrusion cylinder is fixedly connected to one side of the casing close to the inner threaded part, a second notch is arranged on the outer side of the extrusion cylinder, and a notch sealing ring is arranged on one side of the casing close to the annular bevel. The notch sealing ring is used for clamping into the first notch and the second notch. The present application realizes locking by clamping the notch sealing ring between the first notch and the second notch, inhibits relative rotation of two casings, prevents thread reverse unthreading, and the greater the relative rotation trend of the two casings is, the stronger the contraction and holding force of the notch sealing ring is, the synchronous increase of the torsional resistance is, dynamic self-locking is formed, and thus the connection safety and reliability are improved.

Description

Technical Field

[0001] This invention relates to the field of downhole tool technology, and in particular to a direct-connect casing with an anti-rotation locking structure. Background Technology

[0002] Straight-connect casing is a special threaded connection casing without couplings. Its external and internal threads are directly machined at both ends of the casing body. Adjacent casings are directly screwed together by the threads to form a casing string. Compared with traditional coupling casing, straight-connect casing eliminates the independent coupling structure. This structural feature gives straight-connect casing a significant advantage in wellbore size-constrained conditions.

[0003] Currently, direct-connect casing mainly uses threaded structures for connection and sealing. However, when existing direct-connect casing is used downhole, it may encounter alternating loads (formation axial force, fracturing impact) that cause relative rotation at the threaded connection. When the load direction is consistent with the thread direction, reverse uncoupling occurs. Uncoupling leads to loss of preload, thereby reducing connection strength. In severe cases, it can lead to disengagement or leakage, causing well control risks and economic losses. Summary of the Invention

[0004] To address the problems mentioned in the background section, the present invention provides a direct-connection bushing with an anti-rotation locking structure.

[0005] The technical solution of the present invention: A direct-connection sleeve with an anti-rotation locking structure includes a sleeve, on both sides of which are respectively provided with an external thread and an internal thread. An annular inclined surface is provided on the side of the sleeve near the external thread, and the annular inclined surface is provided with a first notch. A compression cylinder is fixedly connected to the side of the sleeve near the internal thread, and a second notch is provided on the outer side of the compression cylinder. A notch sealing ring is provided on the side of the sleeve near the annular inclined surface. The notch sealing ring fits against the annular inclined surface and is used to engage with the first notch and the second notch.

[0006] Preferably, the cross-section of the notch sealing ring is formed by splicing together a right-angled trapezoid and a rectangle.

[0007] Preferably, the cross-section of the second notch is a right trapezoid.

[0008] Preferably, a support ring is provided inside the sleeve on the side near the external thread, a tension spring is fixedly connected to the side of the support ring away from the annular inclined surface, a sliding ring is fixedly connected to the side of the tension spring away from the support ring, the sliding ring is slidably connected to the sleeve, the support ring is located between the notch sealing ring and the sliding ring, and an annular array of extrusion rods is fixedly connected to the sliding ring, the annular array of extrusion rods being used to extrude the notch sealing ring.

[0009] Preferably, a ring array of spring limiting pins is fixedly connected inside the sliding ring.

[0010] Preferably, an outer conical annular surface is provided inside the sleeve on the side near the sliding ring, which is used to compress the telescopic end of the spring limiting pin in the annular array.

[0011] Preferably, a ring array of U-shaped blocks is slidably connected to the side of the sleeve near the external thread, and a ring array of T-shaped extrusion brackets is slidably connected to the side of the sleeve near the U-shaped blocks. Each of the T-shaped extrusion brackets in the ring array is fixedly connected to the support ring. Each T-shaped extrusion bracket in the ring array corresponds one-to-one with each U-shaped block in the ring array. The T-shaped extrusion bracket is used to extrude the corresponding U-shaped block. A ring array of blind holes is provided on the side of the sleeve near the internal thread. Each blind hole in the ring array corresponds one-to-one with each U-shaped block in the ring array. The U-shaped block is used to engage with the corresponding blind hole.

[0012] Preferably, the U-shaped block is provided with a first inclined surface, and the T-shaped extrusion frame is provided with a second inclined surface. The first inclined surface of the U-shaped block is used to extrude the second inclined surface corresponding to the T-shaped extrusion frame.

[0013] Preferably, a ring array of elastic telescopic rods is fixedly connected to the side of the sleeve near the external thread, and the telescopic parts of the ring array of elastic telescopic rods are all fixedly connected to the support ring. The support ring is slidably connected to the sleeve, and a plurality of limiting frames are hinged to the side of the sleeve near the sliding ring. The plurality of limiting frames pass through the sliding ring. One side of the limiting frame is used to limit the support ring, and a spring is fixedly connected between the other side of the limiting frame and the sleeve.

[0014] Preferably, the sliding ring has a pressing surface on the side away from the support ring, which is used to press the other side of the limiting frame.

[0015] The beneficial effects of the present invention are as follows: The present invention achieves locking by inserting the notch sealing ring between the first notch and the second notch, suppressing the relative rotation of the two sleeves, preventing the threads from reversing and uncoiling, and the greater the relative rotation tendency of the two sleeves, the stronger the shrinking and clamping force of the notch sealing ring, and the torsional resistance increases simultaneously, forming a dynamic self-locking, thereby improving the connection safety and reliability. Once the U-shaped block is inserted between the two sleeves, it forms an independent circumferential limit between them. This limit works in conjunction with the clamping action of the notch sealing ring to create a dual anti-torsion mechanism, resulting in redundant locking. This further enhances the stability and reliability of the connection between the two sleeves. On this basis, the tension spring and the elastic telescopic rod work together to apply a reverse thrust to the notch sealing ring, keeping it in an active compression state and creating continuous pre-tightening, which further enhances the clamping effect of the notch sealing ring. Attached Figure Description

[0016] Figure 1 This is a three-dimensional structural diagram of the present invention; Figure 2 This is a three-dimensional structural cross-sectional view of the present invention; Figure 3 This is an exploded view of the three-dimensional structure of the tension spring of the present invention; Figure 4 This is a three-dimensional structural cross-sectional view of the sleeve of the present invention; Figure 5 This is a three-dimensional structural cross-sectional view of the sliding ring of the present invention; Figure 6 This is a three-dimensional structural diagram of the notched sealing ring of the present invention when it is not closed; Figure 7 This is a three-dimensional structural cross-sectional view of the support ring of the present invention; Figure 8 This is a three-dimensional structural diagram illustrating the positional relationship of the second notch in this invention; Figure 9 This is a three-dimensional structural diagram of the two sleeves of the present invention when they are about to be connected; Figure 10 This is a three-dimensional structural diagram of the U-shaped block being inserted into the corresponding blind hole according to the present invention; Figure 11 This is a three-dimensional structural diagram of the notch sealing ring of the present invention after it is closed; Figure 12 For the present invention Figure 11 Enlarged view of point A in the middle.

[0017] Explanation of reference numerals in the attached drawings: 1: Sleeve, 2: External thread, 3: Internal thread, 4: Annular bevel, 5: First notch, 6: Extrusion cylinder, 7: Second notch, 8: Notch sealing ring, 9: Support ring, 10: Tension spring, 11: Sliding ring, 12: Extrusion rod, 13: Spring limit pin, 14: U-shaped block, 15: T-shaped extrusion frame, 16: Blind hole, 17: Elastic telescopic rod, 18: Limit frame. Detailed Implementation

[0018] The embodiments of the present invention will now be described in detail with reference to the accompanying drawings.

[0019] Example 1 A direct-connect bushing with an anti-rotation locking structure, as described in the reference. Figures 1-12As shown, the device includes a sleeve 1, with an external thread 2 and an internal thread 3 on both sides of the sleeve 1. An annular inclined surface 4 is located inside the sleeve 1 near the external thread 2, and the annular inclined surface 4 has a first notch 5. A compression cylinder 6 is fixedly connected to the sleeve 1 near the internal thread 3, and a second notch 7 is located on the outer side of the compression cylinder 6. A notch sealing ring 8 is located inside the sleeve 1 near the annular inclined surface 4. The notch sealing ring 8 can be made of an elastic alloy. When the two sleeves 1 are not joined, the notch sealing ring 8 can be glued inside the sleeve 1 to limit its current position. The notch sealing ring 8 fits against the annular inclined surface 4 and is used to engage the first notch 5 and the second notch 7. The cross-section of the notch sealing ring 8 is a right-angled trapezoid to ensure initial stability between the notch sealing ring 8 and the annular inclined surface 4. The cross-section of the second notch 7 is formed by splicing a right-angled trapezoid and a rectangle. A support ring 9 is located inside the sleeve 1 near the external thread 2, and the support ring 9 is located away from the annular notch 5. A tension spring 10 is fixed to one side of the inclined plane 4. A sliding ring 11, which is slidably connected to the sleeve 1, is fixed to the side of the tension spring 10 away from the support ring 9. The support ring 9 is located between the notch sealing ring 8 and the sliding ring 11. An annular array of extrusion rods 12 is fixed to the sliding ring 11. The annular array of extrusion rods 12 is used to extrude the notch sealing ring 8. An annular array of spring limiting pins 13 is fixed inside the sliding ring 11. An outer conical annular surface is provided inside the sleeve 1 on the side near the sliding ring 11. This outer conical annular surface is used for... The extrusion cylinder 6 is equipped with an inner conical annular surface inside the extrusion cylinder 6. This inner conical annular surface is used to contact the outer conical annular surface inside the sleeve 1 to ensure the fit between the extrusion cylinder 6 and the sleeve 1. When the two sleeves 1 are connected, the extrusion cylinder 6 drives all the spring limit pins 13 and the sliding ring 11 to move downward synchronously through contact with all the spring limit pins 13, so that the tension spring 10 is in a stretched state, providing thrust for the subsequent extrusion rods 12 to extrude the notch sealing ring 8.

[0020] Working principle: When two sleeves 1 need to be connected, using... Figure 9 Taking the state as an example, when the upper sleeve 1 moves down to the point where its internal thread 3 contacts the external thread 2 of the lower sleeve 1, the extrusion cylinder 6 moves along with the upper sleeve 1, passing through the notch sealing ring 8 and reaching the position where it contacts all the spring limit pins 13. Then, by rotating the upper sleeve 1, the internal thread 3 of the upper sleeve 1 and the external thread 2 of the lower sleeve 1 are gradually tightened. During this process, the extrusion cylinder 6 moves along with the upper sleeve 1, thereby driving all the spring limit pins 13 to move downward (during this process, the extrusion cylinder 6 and the telescopic parts of all the spring limit pins 13 rotate relative to each other). All the spring limit pins 13 drive the sliding ring 11 to move downward synchronously (the sliding ring 11 and all the extrusion rods 12 move downward synchronously, and after the extrusion rods 12 move downward, they temporarily disengage from the notch sealing ring 8), so that the tension spring 10 is in a stretched and stored state.

[0021] As the external thread 2 of the lower sleeve 1 gradually screws into the internal thread 3 of the upper sleeve 1, the telescopic ends of all spring limiting pins 13 contact the outer conical annular surface of the lower sleeve 1. As the two sleeves 1 continue to tighten, when the end faces of the two sleeves 1 contact (the first notch 5 and the second notch 7 are in a corresponding state, see reference for details) Figure 11 and Figure 12 The inner conical annular surface on the lower side of the extrusion cylinder 6 contacts the outer conical annular surface inside the sleeve 1. After the telescopic ends of all spring limit pins 13 are compressed by the outer conical annular surface of the lower sleeve 1, they retract. After the telescopic ends of all spring limit pins 13 retract, the tension provided by the tension spring 10 drives the sliding ring 11 and all the extrusion rods 12 to move upward rapidly. Thus, all the extrusion rods 12 push the notch sealing ring 8 between the first notch 5 and the second notch 7 (the notch sealing ring 8 has broken the adhesion with the annular inclined surface 4 during the process of being pushed by all the extrusion rods 12). During this process, the notch sealing ring 8 slides along the annular inclined surface 4 and is compressed by the annular inclined surface 4, causing the notch sealing ring 8 to close. Through the above actions, the following effects are achieved: After the two sleeves 1 are threaded together, the notch sealing ring 8 is inserted between the first notch 5 and the second notch 7. With the guidance and compression of the annular inclined surface 4, the notch sealing ring 8 remains closed and locked after being inserted, thereby achieving axial locking of the two sleeves 1. The structure suppresses the relative rotation tendency between the two sleeves 1, preventing the threads from reversing and uncoiling. When the two sleeves 1 are subjected to external force and rotate relative to each other, the notch sealing ring 8 is further compressed and contracted, and its clamping force increases accordingly. The anti-torsion ability is enhanced simultaneously, forming a dynamic self-locking effect, thereby improving the safety and reliability of the connection between the two sleeves 1.

[0022] Example 2 This embodiment changes the connection method of the support ring 9, allowing the support ring 9 to slide inside the sleeve 1, thereby providing the basic conditions for enhancing the sealing performance of the notch sealing ring 8. For details, please refer to the following.

[0023] Based on Example 1, referring to Figure 4 and Figures 8-12As shown, a ring array of U-shaped blocks 14 is slidably connected to the side of the sleeve 1 near the external thread 2. A ring array of T-shaped extrusion brackets 15 is slidably connected to the side of the sleeve 1 near the U-shaped blocks 14. The ring array of T-shaped extrusion brackets 15 is fixedly connected to the support ring 9. The ring array of T-shaped extrusion brackets 15 corresponds one-to-one with the ring array of U-shaped blocks 14. The T-shaped extrusion brackets 15 are used to extrude the corresponding U-shaped blocks 14. When the two sleeves 1 are not joined together, the T-shaped extrusion brackets 15 and the corresponding U-shaped blocks 14 can be connected by adhesive bonding. At this time, the U-shaped blocks 14 are located inside the sleeve 1. A ring is provided on the side of the sleeve 1 near the internal thread 3. The blind holes 16 in the triangular array and the blind holes 16 in the annular array correspond one-to-one with the U-shaped blocks 14 in the annular array. The U-shaped blocks 14 are used to engage with the corresponding blind holes 16. The U-shaped blocks 14 are provided with a first inclined surface, and the T-shaped extrusion frame 15 is provided with a second inclined surface. The first inclined surface of the U-shaped blocks 14 is used to extrude the second inclined surface of the corresponding T-shaped extrusion frame 15. By moving the T-shaped extrusion frame 15 upward, the second inclined surface of the T-shaped extrusion frame 15 extrudes the first inclined surface of the corresponding U-shaped blocks 14, thereby causing the U-shaped blocks 14 to engage with the sleeve 1 and the corresponding blind hole 16, so as to achieve axial positioning of the two sleeves 1 and suppress the uncoupling of the two sleeves 1.

[0024] Reference Figure 4 , Figure 5 and Figure 10 As shown, an annular array of elastic telescopic rods 17 is fixedly connected to the upper side of the sleeve 1. The telescopic parts of the annular array of elastic telescopic rods 17 are all fixedly connected to the support ring 9. The support ring 9 is slidably connected to the sleeve 1. Several limiting frames 18 are hinged to the side of the sleeve 1 near the sliding ring 11. Several limiting frames 18 pass through the sliding ring 11. One side of the limiting frame 18 is used to limit the support ring 9. A spring is fixedly connected between the other side of the limiting frame 18 and the sleeve 1. When the two sleeves 1 are not connected, all the limiting frames 18 limit the support ring 9 (the springs on the lower side of all the limiting frames 18 are used to make the support ring 9 fixedly connected to the sleeve 1). All the limiting frames 18 maintain the limiting of the support ring 9, and the telescopic parts of all the elastic telescopic rods 17 are in a stretched state. The stability of the stretched state is provided by the locking of the supporting ring 9 by the limiting frames 18. In order to facilitate the installation of the limiting frame 18 into the sleeve 1, the present invention provides an elastic pin at the rotation position of the limiting frame 18 along the sleeve 1, and a limiting hole for bearing the elastic pin is opened in the sleeve 1. The elastic pin is used to restrict the limiting frame 18 in the sleeve 1, which facilitates the installation and makes the limiting frame 18 rotate stably along the sleeve 1 (such as the connection method of the existing watch strap and dial).

[0025] Reference Figure 5 As shown, a pressing surface is provided on the lower side of the sliding ring 11. The pressing surface is inclined and is used to press the other side of the limiting frame 18.

[0026] Working principle: During the docking process of the two sleeves 1, the support ring 9 is fixed in the current position by the limit of all the limit brackets 18. The upper sleeve 1 is squeezed by the extrusion cylinder 6 to squeeze all the spring limit pins 13, so that all the spring limit pins 13 drive the sliding ring 11 to move downward and stretch the tension spring 10.

[0027] When the sliding ring 11 moves to the point where its upper pressing surface contacts the lower side of all the limiting brackets 18, the end faces of the two sleeves 1 are close to touching. At this time, the telescopic ends of all the spring limiting pins 13 are in contact with the outer conical ring surface of the lower sleeve 1.

[0028] When the end faces of the two sleeves 1 are in contact (the center lines of all U-shaped blocks 14 coincide with the center lines of the corresponding blind holes 16), while the telescopic ends of all spring limit pins 13 retract, the pressing surface of the sliding ring 11 has pressed the lower side of all limit frames 18. At this time, the supporting force provided by the adjacent springs of the limit frames 18 is less than the pressing force provided above. All limit frames 18 swing along the lower sleeve 1, thereby releasing the limit on the support ring 9. The sliding ring 11 moves upward by the tension provided by the tension spring 10, while the support ring 9 drives all the T-shaped pressing frames 15 to move upward by the tension provided by all the elastic telescopic rods 17. During the upward movement of the T-shaped pressing frames 15, they press the corresponding U-shaped blocks 14 (at this time, the pressing force of the T-shaped pressing frames 15 is greater than the adhesive force with the corresponding U-shaped blocks 14), causing the U-shaped blocks 14 to be inserted into the corresponding blind holes 16, thereby restricting the reversal of the upper sleeve 1 (at this time, the T-shaped pressing frames 15 have not moved to the limit position, see details). Figure 10 Meanwhile, as the sliding ring 11 pushes the notched sealing ring 8 between the first notch 5 and the second notch 7 through all the extrusion rods 12, the tension spring 10 gradually recovers. At this time, with the recovery of the telescopic parts of all the elastic telescopic rods 17, the upward sliding height of the sliding ring 11 is higher than the height mentioned in Embodiment 1, thereby enabling all the extrusion rods 12 to obtain a continuous reverse extrusion force on the notched sealing ring 8. The above actions achieve the following effects: By inserting all the U-shaped blocks 14 between the two sleeves 1, a circumferential limit is added between the two sleeves 1. With the clamping force provided by the notch sealing ring 8 and the axial resistance provided by all the U-shaped blocks 14, a double anti-torsion mechanism is formed, creating redundant locking, thereby further improving the stability and reliability of the connection between the two sleeves 1. Subsequently, the elastic force provided by the tension spring 10 and all the elastic telescopic rods 17 provides reverse compression to the notch sealing ring 8, forming active pre-tightening, thereby enhancing the clamping effect of the notch sealing ring 8.

[0029] The above description is merely a specific embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any changes or substitutions that can be easily conceived by those skilled in the art within the scope of the technology disclosed in the present invention should be included within the scope of protection of the present invention.

Claims

1. A direct-connection bushing with an anti-rotation locking structure, characterized in that, The sleeve (1) includes an external thread (2) and an internal thread (3) on both sides of the sleeve (1). An annular inclined surface (4) is provided on the side of the sleeve (1) near the external thread (2). A first notch (5) is provided on the annular inclined surface (4). A compression cylinder (6) is fixedly connected to the side of the sleeve (1) near the internal thread (3). A second notch (7) is provided on the outside of the compression cylinder (6). A notch sealing ring (8) is provided on the side of the sleeve (1) near the annular inclined surface (4). The notch sealing ring (8) fits against the annular inclined surface (4) and is used to engage the first notch (5) and the second notch (7). A support ring (9) is provided inside the sleeve (1) on the side near the external thread (2). A tension spring (10) is fixed to the side of the support ring (9) away from the annular inclined surface (4). A sliding ring (11) is fixed to the side of the tension spring (10) away from the support ring (9). The sliding ring (11) is slidably connected to the sleeve (1). The support ring (9) is located between the notch sealing ring (8) and the sliding ring (11). An annular array of extrusion rods (12) is fixed to the sliding ring (11). The annular array of extrusion rods (12) is used to extrude the notch sealing ring (8). The sliding ring (11) is fixed with a ring array of spring limiting pins (13). An outer conical annular surface is provided on the side of the sleeve (1) near the sliding ring (11), which is used to press the telescopic end of the spring limiting pin (13) of the annular array.

2. A direct-connection bushing with an anti-rotation locking structure according to claim 1, characterized in that, The cross section of the notch sealing ring (8) is composed of right-angled trapezoids and rectangles.

3. A direct-connection bushing with an anti-rotation locking structure according to claim 1, characterized in that, The cross-section of the second notch (7) is a right trapezoid.

4. A direct-connection bushing with an anti-rotation locking structure according to claim 1, characterized in that, The sleeve (1) is slidably connected to a U-shaped block (14) in an annular array on the side near the external thread (2). The sleeve (1) is slidably connected to a T-shaped extrusion frame (15) in an annular array on the side near the U-shaped block (14). The T-shaped extrusion frames (15) in the annular array are all fixedly connected to the support ring (9). The T-shaped extrusion frames (15) in the annular array correspond one-to-one with the U-shaped blocks (14) in the annular array. The T-shaped extrusion frames (15) are used to extrude the corresponding U-shaped blocks (14). The sleeve (1) is provided with a blind hole (16) in an annular array on the side near the internal thread (3). The blind hole (16) in the annular array corresponds one-to-one with the U-shaped blocks (14) in the annular array. The U-shaped blocks (14) are used to be inserted into the corresponding blind hole (16).

5. A direct-connection bushing with an anti-rotation locking structure according to claim 4, characterized in that, The U-shaped block (14) is provided with a first inclined surface, and the T-shaped extrusion frame (15) is provided with a second inclined surface. The first inclined surface of the U-shaped block (14) is used to extrude the second inclined surface corresponding to the T-shaped extrusion frame (15).

6. A direct-connection bushing with an anti-rotation locking structure according to claim 5, characterized in that, The sleeve (1) is fixedly connected to a ring array of elastic telescopic rods (17) on the side near the external thread (2). The telescopic parts of the ring array of elastic telescopic rods (17) are all fixedly connected to the support ring (9). The support ring (9) is slidably connected to the sleeve (1). A plurality of limiting frames (18) are hinged to the side of the sleeve (1) near the sliding ring (11). The plurality of limiting frames (18) all pass through the sliding ring (11). One side of the limiting frame (18) is used to limit the support ring (9). The other side of the limiting frame (18) is fixedly connected to the sleeve (1).

7. A direct-connection bushing with an anti-rotation locking structure according to claim 6, characterized in that, The sliding ring (11) has a pressing surface on the side away from the support ring (9), which is used to press the other side of the limiting frame (18).

Images