Pipe splicing connection device and subsea Christmas tree system

Abstract

The application discloses a pipeline plug-in connecting device, which comprises a target body and a plug-in head, and the target body and the plug-in head can be detachably connected with a drill rod and a casing pipe. When the pipeline is connected, the target body is connected with one pipeline, the plug-in head is connected with another adjacent pipeline, the plug-in head is inserted into a plug-in hole of the target body, the plug-in head extrudes a clamping element, the clamping element is deformed, and after the plug-in head is inserted in place, the plug-in head is connected with the target body through plug-in connection. The connecting and fastening operation is convenient, the adjacent pipelines are connected through the plug-in head and a switching cavity, the clamping element clamps the plug-in head under the action of the restoring deformation force of the clamping element, the plug-in head is prevented from slipping off, and the reliability of the pipeline connection is improved. A sealing assembly is arranged between the plug-in head and the plug-in hole, the connection sealing property of the plug-in head and the target body is improved, and the reliability of the pipeline connection is improved. The application further discloses an underground production tree system, which comprises an underground pipeline and the pipeline plug-in connecting device.

Description

Technical Field

[0001] This invention relates to the technical field of oil and gas extraction equipment and its supporting facilities, and in particular to a pipeline plug-in connection device and an underground wellhead system. Background Technology

[0002] In oil and gas drilling, the traditional method of converging multiple well groups is through surface production trees. This method requires connecting multiple wells onto a production tree via pipelines after drilling is completed, necessitating repeated pipeline laying operations. This makes the well construction process complex, occupies a significant amount of surface space, and the converging pipelines are directly exposed on the surface, making them highly susceptible to damage. Furthermore, it poses certain risks in high-pressure gas (oil) areas. Chinese patents CN107448168A (discloses an integrated production tree), CN114086904A (discloses a production tree system), and CN112065322A (discloses a wellhead production tree) all only allow surface connection via pipelines to achieve the convergence and connection of multiple well groups; they cannot achieve underground docking, sealing, and connection of well groups.

[0003] The production mode of connecting multiple wells underground to form a true "underground factory" has always been considered an ideal production operation method, but this method has high requirements for underground connection operation and sealing and pressure resistance devices. Summary of the Invention

[0004] The purpose of this invention is to provide a pipe plug-in connection device and an underground tree system to solve the problems existing in the prior art, improve the convenience of underground pipe connection operation, ensure the sealing and pressure resistance performance of underground pipes, and reduce the ground space occupied by the system by constructing an underground tree system.

[0005] To achieve the above objectives, the present invention provides the following solution: The present invention provides a pipe insertion connection device, comprising:

[0006] The target body is detachably connected to the drill pipe and the casing. The target body has a transition cavity. When the target body is connected to the drill pipe and the casing, the transition cavity is connected to the drill pipe and the casing. The side wall of the target body has an insertion hole, which is connected to the transition cavity. A clamping element is provided on the inner wall of the insertion hole.

[0007] The connector is a hollow cylindrical structure. One end of the connector can be detachably connected to the drill pipe or casing, and the other end of the connector is connected to the insertion hole. The connector communicates with the adapter cavity through the insertion hole. When the connector is inserted into the insertion hole, it forces the clamping element to deform. After the connector is fully inserted into the insertion hole, the clamping element clamps the connector. A sealing component is also provided between the connector and the insertion hole.

[0008] Preferably, the clamping element includes an anti-detachment snap ring, which is disposed in the insertion hole. The anti-detachment snap ring has a C-shaped ring structure with a notch in the circumferential direction. A slot is provided on the inner side wall of the anti-detachment snap ring, and a locking block that matches the slot is provided on the outer side wall of the insertion joint. The insertion joint extends into the anti-detachment snap ring, and the two are locked together.

[0009] Preferably, the axial cross-section of the locking block is trapezoidal, and the side of the locking block near the adapter cavity has an inclined surface, which is inclined towards the direction of gradually approaching the adapter cavity axis.

[0010] Preferably, the slot is C-shaped and the block is a ring structure; there are multiple sets of blocks, all of which are arranged along the axial direction of the connector, and the slot and the block correspond one-to-one.

[0011] Preferably, the clamping element further includes a straightening coil spring, which is sleeved on the outside of the anti-disengagement spring. The straightening coil spring has a ring structure and is coaxially arranged with the insertion hole. The straightening coil spring includes a coil spring body and a spring piece. One end of the spring piece is connected to the coil spring body, and the other end of the spring piece extends obliquely toward the axial direction of the coil spring body and abuts against the outer side wall of the anti-disengagement spring. The end of the spring piece connected to the coil spring body is located close to the transition cavity. There are multiple sets of spring pieces, and all the spring pieces are evenly distributed circumferentially around the axis of the coil spring body.

[0012] Preferably, the free end of the spring sheet has a clamping section, which is arranged parallel to the axis of the coil spring body.

[0013] Preferably, the target body is further connected to a retaining spring cover, which is a hollow structure and has a through hole that allows the connector to pass through. The retaining spring cover is detachably connected to the target body and presses the anti-detachment retaining spring into the connector hole.

[0014] Preferably, the ends of the insertion hole and the through hole that are away from the adapter cavity are both variable diameter holes, and the larger diameter ends of the insertion hole and the through hole face the side away from the adapter cavity.

[0015] Preferably, the sealing assembly includes multiple sets of sealing rings, the inner wall of the insertion hole has a mounting groove adapted to the sealing ring, the sealing ring is disposed in the mounting groove, and all the sealing rings are arranged along the axial direction of the insertion hole.

[0016] The present invention also provides an underground wellhead system, including underground pipes and the above-mentioned pipe plug-in connection device, wherein adjacent underground pipes are connected by the pipe plug-in connection device.

[0017] The present invention achieves the following technical effects compared to the prior art:

[0018] The pipe splicing connection device of the present invention includes a target body and a splice. Both the target body and the splice can be detachably connected to drill pipes and casings. During pipe connection, the target body can be connected to one pipe, and the splice can be connected to another adjacent pipe. The splice is inserted into the splice hole of the target body. The splice squeezes the clamping element, causing the clamping element to deform. After the splice is in place, the splice and the target body are spliced ​​together. The connection and fastening operation is convenient. Adjacent pipes are connected to the adapter cavity through the splice. Under the force of the clamping element restoring its deformation, the clamping element clamps the splice, preventing the splice from slipping and improving the reliability of the pipe connection. At the same time, a sealing component is provided between the splice and the splice hole, which enhances the connection sealing between the splice and the target body, further improving the reliability of the pipe connection.

[0019] The present invention also provides an underground tree system, including underground pipes and the aforementioned pipe plug-in connection device. Adjacent underground pipes are connected by the pipe plug-in connection device, which reduces the occupation of ground space and improves the construction efficiency of the underground tree system. Attached Figure Description

[0020] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0021] Figure 1 This is a schematic diagram of the pipe insertion connection device disclosed in the embodiments of the present invention;

[0022] Figure 2 for Figure 1 A cross-sectional view along the AA direction;

[0023] Figure 3 for Figure 2 Enlarged view of point B in the middle;

[0024] Figure 4 This is a schematic diagram of the target body of the pipe insertion connection device disclosed in the embodiment of the present invention;

[0025] Figure 5 for Figure 4 A cross-sectional view along the CC direction;

[0026] Figure 6 for Figure 5 Enlarged view of point D in the middle;

[0027] Figure 7 This is a partial structural schematic diagram of the target body of the pipe insertion connection device disclosed in the embodiments of the present invention;

[0028] Figure 8 for Figure 7 A cross-sectional view along the EE direction;

[0029] Figure 9 This is a schematic diagram of the anti-disengagement snap ring of the pipe plug connection device disclosed in the embodiments of the present invention;

[0030] Figure 10 for Figure 9 A cross-sectional view along the FF direction;

[0031] Figure 11 This is a front view schematic diagram of the straightening coil spring of the pipe insertion connection device disclosed in the embodiment of the present invention;

[0032] Figure 12 This is a side view of the straightening coil spring of the pipe insertion connection device disclosed in the embodiment of the present invention;

[0033] Figure 13 for Figure 12 A cross-sectional view along the GG direction;

[0034] Figure 14 for Figure 13 Enlarged structural diagram at point H;

[0035] Figure 15 This is a schematic diagram of the snap ring cover of the pipe insertion connection device disclosed in the embodiment of the present invention;

[0036] Figure 16 for Figure 15 A cross-sectional view along direction II;

[0037] Figure 17 This is a schematic diagram of the connector structure of the pipe plug connection device disclosed in the embodiment of the present invention;

[0038] Figure 18 for Figure 17A cross-sectional view along the JJ direction.

[0039] Among them, 100 is a pipe insertion connection device;

[0040] 1 is the target body, 101 is the insertion hole, 102 is the mounting groove, 2 is the insertion connector, 201 is the locking block, 3 is the clamping element, 4 is the adapter cavity, 5 is the anti-detachment snap ring, 501 is the notch, 502 is the slot, 6 is the straightening coil spring, 601 is the coil spring body, 602 is the spring piece, 603 is the pressing section, 7 is the snap ring cover, and 8 is the sealing ring. Detailed Implementation

[0041] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. 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 are within the scope of protection of the present invention.

[0042] The purpose of this invention is to provide a pipe plug-in connection device and an underground tree system to solve the problems existing in the prior art, improve the convenience of underground pipe connection operation, ensure the sealing and pressure resistance performance of underground pipes, and reduce the ground space occupied by the system by constructing an underground tree system.

[0043] To make the above-mentioned objects, features and advantages of the present invention more apparent and understandable, the present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments.

[0044] This invention provides a pipe insertion connection device 100, including a target body 1 and an insertion connector 2. The target body 1 can be detachably connected to a drill rod and a casing. The target body 1 has a transition cavity 4. When the target body 1 is connected to the drill rod and the casing, the transition cavity 4 is connected to the drill rod and the casing. The side wall of the target body 1 has an insertion hole 101, which is connected to the transition cavity 4. A clamping element 3 is provided on the inner wall of the insertion hole 101. The connector 2 is a hollow cylindrical structure. One end of the connector 2 can be detachably connected to the drill pipe and casing, and the other end of the connector 2 is connected to the insertion hole 101. The connector 2 is connected to the adapter cavity 4 through the insertion hole 101. When the connector 2 is inserted into the insertion hole 101, it forces the clamping element 3 to deform. After the connector 2 is inserted into the insertion hole 101, the clamping element 3 clamps the connector 2. A sealing component is also provided between the connector 2 and the insertion hole 101.

[0045] The pipe connection device 100 of the present invention includes a target body 1 and a connector 2. Both the target body 1 and the connector 2 can be detachably connected to drill pipes and casings. When connecting pipes, the target body 1 can be connected to one pipe, and the connector 2 can be connected to another adjacent pipe. The connector 2 is inserted into the insertion hole 101 of the target body 1. The connector 2 squeezes the clamping element 3, and the clamping element 3 deforms. After the connector 2 is inserted into place, the connector 2 and the target body 1 are connected. The connection and fastening operation is convenient. Adjacent pipes are connected to the adapter cavity 4 through the connector 2. Under the force of the clamping element 3 restoring its deformation, the clamping element 3 clamps the connector 2, preventing the connector 2 from slipping and improving the reliability of the pipe connection. At the same time, a sealing component is provided between the connector 2 and the insertion hole 101 to enhance the connection sealing between the connector 2 and the target body 1, further improving the reliability of the pipe connection.

[0046] Specifically, the clamping element 3 includes an anti-detachment spring 5, which is disposed within the insertion hole 101. The anti-detachment spring 5 has a C-shaped ring structure with a notch 501 in the circumferential direction. A groove 502 is provided on the inner side wall of the anti-detachment spring 5, and a locking block 201 that matches the groove 502 is provided on the outer side wall of the insertion connector 2. The insertion connector 2 extends into the anti-detachment spring 5, thereby achieving a locking connection between the two. When the insertion connector 2 extends into the anti-detachment spring 5 in the insertion hole 101, the anti-detachment spring 5 is expanded, and the notch 501 becomes larger. After the locking block 201 of the insertion connector 2 slides into the groove 502, the locking block 201 engages with the groove 502. Under the force of restoring deformation, the anti-detachment spring 5 clamps the insertion connector 2, thereby achieving a locking connection between the target body 1 and the insertion connector 2. Furthermore, the locking block 201 and the groove 502 enhance the connection strength of the insertion connector 2.

[0047] In this specific embodiment, the axial cross-section of the locking block 201 is trapezoidal, specifically a right-angled trapezoid. The side of the locking block 201 closest to the adapter cavity 4 has an inclined surface, which tilts towards the axis of the adapter as it gradually approaches the adapter cavity 4. During the insertion of the connector 2 into the anti-disengagement spring 5, the inclined surface of the locking block 201 facilitates the insertion of the connector 2. Simultaneously, during insertion, the inclined surface gradually pushes the anti-disengagement spring 5, allowing the connector 2 to be smoothly inserted. After insertion, the radial plane of the locking block 201 engages with the slot 502, preventing the connector 2 from slipping. The engagement between the connector 2 and the anti-disengagement spring 5 ensures a reliable connection between the connector 2 and the target body 1. After successful engagement, the connector exhibits high strength and improves the adaptability of the device, preventing the connector 2 from loosening under high-pressure environments.

[0048] Correspondingly, the slot 502 is C-shaped and the block 201 is a ring structure, which improves the uniformity of force on the connector 2 and the anti-disengagement spring 5. In order to further improve the connection reliability between the anti-disengagement spring 5 and the connector 2, there are multiple sets of blocks 201. All the blocks 201 are arranged along the axial direction of the connector 2. The slot 502 and the blocks 201 correspond one-to-one, which further enhances the connection firmness and improves the working reliability of the device.

[0049] More specifically, the clamping element 3 also includes a straightening spring 6, which is sleeved on the outside of the anti-disengagement spring 5. The straightening spring 6 has a ring structure and is coaxially arranged with the insertion hole 101. Since the anti-disengagement spring 5 has a notch 501, in order to avoid the anti-disengagement spring 5 from being misaligned and affecting the smooth insertion of the connector 2, the straightening spring 6 is set to ensure that the anti-disengagement spring 5 is coaxial with the insertion hole 101, and to ensure the smooth connection of adjacent pipelines when the connector 2 is inserted. The centering spring 6 includes a spring body 601 and a spring piece 602. One end of the spring piece 602 is connected to the spring body 601, and the other end of the spring piece 602 extends obliquely towards the axis of the spring body 601 and abuts against the outer wall of the anti-disengagement spring 5. The end of the spring piece 602 connected to the spring body 601 is located near the adapter cavity 4. There are multiple sets of spring pieces 602, all of which are evenly distributed circumferentially around the axis of the spring body 601. The centering spring 6 can achieve the purpose of positioning the anti-disengagement spring 5, ensuring the stability and centering of the anti-disengagement spring 5 during insertion, and ensuring that the connector 2 can be correctly inserted into the target body 1. The spring piece 602 also prevents the centering spring 6 from affecting the opening and closing of the anti-disengagement spring 5, further ensuring that the anti-disengagement spring 5 can be snapped into place with the connector 2. The spring pieces 602 are evenly distributed circumferentially around the axis of the centering spring 6, which improves the uniformity of force on the anti-disengagement spring 5.

[0050] In other specific embodiments of the present invention, the free end of the spring 602 has a pressing section 603, which is arranged parallel to the axis of the coil spring body 601, thereby increasing the contact area between the spring 602 and the anti-disengagement spring 5 and improving the working reliability of the straightening coil spring 6.

[0051] To limit the axial position of the clamping element 3, the target body 1 is also connected to a snap ring cover 7. The snap ring cover 7 is a hollow structure with a through hole that allows the connector 2 to pass through. The snap ring cover 7 is detachably connected to the target body 1 and presses the anti-disengagement snap ring 5 into the connector hole 101. By using the snap ring cover 7 to press the anti-disengagement snap ring 5 and the centering spring 6, the stability of the clamping element 3 is improved, and its axial sliding misalignment is prevented. In this specific embodiment, the snap ring cover 7 is detachably connected to the target body 1 using fastening screws. The connection, fastening, and disassembly are convenient. Multiple fastening screws can be set, and the fastening screws are evenly distributed around the axis of the snap ring cover 7, improving the uniformity of force on the snap ring cover 7 and the clamping element 3 and extending the service life of the device. In other specific embodiments of the present invention, other fastening elements with different structures can also be used, such as blocks, retaining rings, etc., or a positioning groove can be provided in the connector hole 101 to achieve the positioning of the clamping element 3. In practical applications, adjustments can be made according to actual working conditions to improve the flexibility and adaptability of the device.

[0052] It should also be noted that both the insertion hole 101 and the end of the through hole furthest from the adapter cavity 4 are reducing holes. The larger diameter end of the insertion hole 101 and the through hole faces the side furthest from the adapter cavity 4, while the larger diameter end faces the connector 2, facilitating the insertion of the connector 2 and improving the efficiency of connecting adjacent pipes. In practical applications, the reducing hole can be designed as a trumpet shape or a frustum shape to reduce the difficulty of insertion operations.

[0053] In addition, the sealing assembly includes multiple sets of sealing rings 8. The inner wall of the insertion hole 101 has mounting grooves 102 that fit the sealing rings 8. The sealing rings 8 are disposed within the mounting grooves 102. All the sealing rings 8 are arranged along the axial direction of the insertion hole 101. The insertion connector 2 compresses the sealing rings 8 to achieve a sealed connection with the target body 1. The multiple sets of sealing rings 8 further enhance the sealing performance. The sealing rings 8 can be made of rubber, enabling the device to meet high sealing requirements.

[0054] Furthermore, the present invention also provides an underground tree system, including underground pipes and the aforementioned pipe plug-in connection device 100, wherein adjacent underground pipes are connected by plugging in the pipe plug-in connection device 100, thereby reducing the occupation of ground space and improving the construction efficiency of the underground tree system.

[0055] During underground pipeline connection operations, the target body 1 and the connector 2 are connected to the drill pipe or casing of the corresponding well section. The target body 1 is lowered to the preset well depth, with the side connector hole 101 aligned with the connector well position. The connector 2 is then inserted into the connector hole 101 using the drill pipe or casing. The notch 501 of the anti-disengagement spring 5 opens, ensuring that the locking block 201 on the connector 2 passes smoothly. Afterward, the anti-disengagement spring 5 returns to its original position under elastic action, and the internal locking groove 502 engages with the locking block 201 of the connector 2. The front end of the connector 2 is sealed by the sealing ring 8 provided on the side wall of the target body 1. It should be noted that in this specific embodiment, both the target body 1 and the connector 2 are connected by threads to the drill pipe and casing, ensuring a secure connection and convenient operation.

[0056] The underground wellhead system of this invention can achieve production docking of multiple well groups with a single plug-in, improving the efficiency of well construction. At the same time, completing the plug-in docking underground eliminates the need for multiple pipeline laying operations on the surface, saving the land required for connecting multiple wells on the surface, avoiding direct exposure of the converging pipeline on the surface, and reducing the pipeline damage rate.

[0057] Specific examples have been used to illustrate the principles and implementation methods of this invention. The descriptions of the above embodiments are only for the purpose of helping to understand the method and core ideas of this invention. Furthermore, those skilled in the art will recognize that, based on the ideas of this invention, there will be changes in the specific implementation methods and application scope. Therefore, the content of this specification should not be construed as a limitation of this invention.

Claims

1. A pipe insertion connection device, characterized in that, include: The target body is detachably connected to the drill pipe and the casing. The target body has a transition cavity. When the target body is connected to the drill pipe and the casing, the transition cavity is connected to the drill pipe and the casing. The side wall of the target body has an insertion hole, which is connected to the transition cavity. A clamping element is provided on the inner wall of the insertion hole. The connector is a hollow cylindrical structure. One end of the connector can be detachably connected to the drill pipe or casing, and the other end of the connector is connected to the insertion hole. The connector communicates with the adapter cavity through the insertion hole. When the connector is inserted into the insertion hole, it forces the clamping element to deform. After the connector is fully inserted into the insertion hole, the clamping element clamps the connector. A sealing component is also provided between the connector and the insertion hole. The clamping element includes an anti-detachment snap ring, which is disposed in the insertion hole. The anti-detachment snap ring has a C-shaped ring structure and a notch in the circumferential direction. A slot is provided on the inner side wall of the anti-detachment snap ring, and a locking block that matches the slot is provided on the outer side wall of the insertion joint. The insertion joint extends into the anti-detachment snap ring, and the two are locked together. The clamping element also includes a straightening coil spring, which is sleeved on the outside of the anti-disengagement spring. The straightening coil spring has a ring structure and is coaxially arranged with the insertion hole. The straightening coil spring includes a coil spring body and a spring piece. One end of the spring piece is connected to the coil spring body, and the other end of the spring piece extends obliquely toward the axial direction of the coil spring body and abuts against the outer side wall of the anti-disengagement spring. The end of the spring piece connected to the coil spring body is located close to the transition cavity. There are multiple sets of spring pieces, and all the spring pieces are evenly distributed circumferentially around the axis of the coil spring body.

2. The pipe insertion connection device according to claim 1, characterized in that: The axial cross-section of the card block is trapezoidal, and the side of the card block near the adapter cavity has an inclined surface, which gradually approaches the adapter cavity.

3. The pipe insertion connection device according to claim 1, characterized in that: The slot is C-shaped and the block is a ring structure; there are multiple sets of blocks, all of which are arranged along the axial direction of the connector, and the slot and the block correspond one-to-one.

4. The pipe insertion connection device according to claim 1, characterized in that: The free end of the spring sheet has a clamping section, which is arranged parallel to the axis of the coil spring body.

5. The pipe insertion connection device according to any one of claims 1-4, characterized in that: The target body is also connected to a retaining spring cover, which is a hollow structure and has a through hole that allows the connector to pass through. The retaining spring cover is detachably connected to the target body and presses the anti-detachment retaining spring into the connector hole.

6. The pipe insertion connection device according to claim 5, characterized in that: Both the insertion hole and the through hole have variable diameter ends away from the adapter cavity, with the larger diameter end of the insertion hole and the through hole facing away from the adapter cavity.

7. The pipe insertion connection device according to any one of claims 1-4, characterized in that: The sealing assembly includes multiple sets of sealing rings. The inner wall of the insertion hole has a mounting groove that matches the sealing ring. The sealing ring is disposed in the mounting groove, and all the sealing rings are arranged along the axial direction of the insertion hole.

8. An underground wellhead system, comprising underground pipelines, characterized in that: It also includes the pipe plug-in connection device according to any one of claims 1-7, wherein adjacent underground pipes are connected by plugging in the pipe plug-in connection device.

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