A swivel type pin preventer and workover rig

Abstract

This utility model belongs to the technical field of oil well workover equipment, specifically relating to a rotary snap-fit ​​blowout preventer and workover rig. It includes a blowout preventer cylinder, which comprises a rotating housing and a fixed housing. A tubular support return pipe is fixedly connected to the fixed housing, and the inner cavity of the support return pipe communicates with the inner cavity of the blowout preventer cylinder. A hydraulic cylinder is installed at the upper end of the support return pipe, and the piston rod of the hydraulic cylinder is hinged to the rotating housing. A rotary bearing rotatably connects the lower end of the support return pipe to a rotary seat, and a rotary drive mechanism is installed on the side of the rotary seat. This utility model solves the problem of the need for subsequent liquid cleanup in existing technologies, fundamentally reducing environmental pollution and operational burden. It also overcomes the shortcomings of existing blowout preventers, such as high space requirements and proximity to the wellhead leading to limited manual operation, improving operational flexibility and safety, and achieving fully automated operation.

Description

Technical Field

[0001] This utility model belongs to the technical field of oil well workover equipment, specifically relating to a rotary snap-fit ​​blowout preventer and a workover machine. Background Technology

[0002] In the oil extraction industry, oil wells inevitably encounter various problems during long-term operation, such as stuck pumps, broken sucker rods, and severe tubing wear. These problems seriously affect the normal production of oil wells, necessitating well workover operations. The main process of well workover is to use a workover truck to retrieve the sucker rods and tubing from the well, place them on a pipe rack for inspection or replacement, and then lower them back into the well to continue production after the problem is resolved. Currently, during well workover operations in oilfields, two major technical challenges are often encountered when retrieving and running tubing: first, aligning the male and female threads of the tubing string relies on manual operation, resulting in low alignment accuracy and efficiency, which affects the progress of automated well workover; second, after uncoupling, the residual oil-water mixture in the tubing string is prone to splashing during the retrieval process, not only polluting the working environment and increasing the amount of cleaning work, but also posing safety hazards.

[0003] Existing technologies include research on installing blowout preventers (BOPs) on workover rigs, such as patent CN109763780A - Multifunctional Workover Device. This device integrates coupling detection, tubing string reconnection, and oil spill prevention functions by installing a BOP on the base, along with an inner lining structure and guide ring structure. This reduces manual intervention to some extent. However, the BOP can only prevent oil-water mixtures from splashing everywhere and cannot collect the liquid. Ultimately, the liquid will still flow into the work platform through the bottom of the BOP, requiring subsequent cleaning. Furthermore, the device requires a large amount of space during installation, is close to the wellhead, and leaves limited space at the wellhead when retracting to the waiting position. If other manual operations are required at the wellhead, this will be significantly restricted, resulting in insufficient ease of operation. For example, the patent CN206928930U-Blowout Preventer adopts an open-closed dual blowout preventer structure. It prevents the splashing of oil-water mixture by closing and opening the blowout preventer, thus ensuring the cleanliness of the operation. However, the device has a single function, only having the function of preventing splashing. It cannot realize the function of connecting the tubing string. It still needs to be used in conjunction with other devices to complete the connection operation. The overall operation process is not coherent enough, making it difficult to further improve the automation and integration level of well workover operations.

[0004] In summary, while existing blowout preventers can suppress oil and water splashing to some extent, they still have significant limitations in terms of functional integration, adaptability to working space, and liquid collection capabilities. On the one hand, their functions are relatively singular, focusing solely on blowout prevention without effectively integrating with key processes such as alignment and straightening, thus hindering the overall automation level of well workover operations. On the other hand, their structural designs often occupy a large amount of space around the wellhead, limiting manual emergency operations or other auxiliary work, and they generally lack effective collection and diversion capabilities for splashed liquids, failing to fundamentally solve environmental pollution and platform cleaning problems, and making it difficult to meet the actual needs of efficient, automated, and convenient well workover operations. Therefore, a new technical solution is needed to address these technical problems. Utility Model Content

[0005] The purpose of this utility model is to provide a rotary snap-fit ​​blowout preventer and workover rig to solve the problems mentioned in the background art. Although the current blowout preventers have made breakthroughs in blowout prevention or snap-fit ​​single functions, they still have defects in liquid collection, spatial adaptability and functional integration, making it difficult to meet the actual needs of efficient, automated and convenient workover operations.

[0006] To achieve the above objectives, this utility model provides the following technical solution: a rotary snap-fit ​​blowout preventer, comprising a blowout preventer cylinder, a guide ring provided at the inner top of the blowout preventer cylinder, a snap-fit ​​inner liner seat provided at the inner lower part of the blowout preventer cylinder, a snap-fit ​​inner liner installed in the snap-fit ​​inner liner seat, the blowout preventer cylinder comprising a rotating shell and a fixed shell that can be opened and closed by a hinge, a tubular support return pipe fixedly connected to the fixed shell, the inner cavity of the support return pipe communicating with the inner cavity of the blowout preventer cylinder, a hydraulic cylinder provided at the upper end of the support return pipe, the piston rod of the hydraulic cylinder being hinged to the rotating shell, a rotary seat rotatably connected to the lower end of the support return pipe via a rotary bearing, a rotary drive mechanism provided on the side of the rotary seat, the output end of the rotary drive mechanism being drivenly connected to the rotary bearing and driving the support return pipe to rotate through the rotary bearing.

[0007] Furthermore, the supporting return pipe includes a guide pipe and a support pipe, which are arranged in an L-shape in the vertical direction; one end of the guide pipe is connected to the upper end of the support pipe through a right-angle bend A, and the other end of the guide pipe is connected to a drain pipe through a right-angle bend B. The drain pipe and the guide pipe are arranged in an L-shape in the horizontal direction, and the lower end of the support pipe is connected to the upper center position of the rotary bearing; the end of the drain pipe away from the guide pipe is connected to the side wall of the fixed housing away from the mating surface of the rotating housing.

[0008] Furthermore, a mounting base is fixed on the side wall of the guide pipe near the drain pipe, and the mounting base is hinged to the cylinder body of the hydraulic cylinder; the piston rod of the hydraulic cylinder is hinged to the side wall of the rotating housing near the hinge.

[0009] Furthermore, the rotary drive mechanism includes a rotary motor and a reducer. The reducer is connected to the output end of the rotary motor and is connected to the rotary bearing. The rotary motor drives the support return pipe to rotate around its own axis through the reducer and the rotary bearing, thereby driving the blowout preventer to rotate as a whole.

[0010] In addition to the above technical solutions, there is also a workover rig equipped with the rotary snap-fit ​​blowout preventer, wherein the rotary drive mechanism of the rotary snap-fit ​​blowout preventer is fixed on the workover rig platform.

[0011] Compared with the prior art, the beneficial effects of this utility model are: 1. This utility model integrates blowout preventer (BOP) design with a built-in snap-fit ​​liner, combining a closable rotating shell with a fixed shell, and integrating a support return pipe. This achieves integrated BOP and snap-fit ​​functions, allowing the BOP to both seal the coupling to prevent liquid splashing during tubing string operation and guide the male and female snaps to align via the snap-fit ​​liner. This collaborative operation significantly improves the automation level and continuity of well workover operations. The tubular support return pipe and BOP form a closed, directional liquid drainage path, allowing residual oil-water mixture in the tubing string to be directly drained into the workover rig's platform sump through the support return pipe. This effectively prevents liquid from flowing out from the bottom of the BOP and contaminating the workover platform. This new technology solves the problem of the need for subsequent liquid cleanup in existing technologies, fundamentally reducing environmental pollution and operational burden. Furthermore, through the design of the rotary bearing and rotary drive mechanism, the entire blowout preventer can rotate flexibly between the working and waiting positions, allowing it to be quickly moved away when not in operation. This provides ample wellhead operating space for manual intervention or other auxiliary operations, overcoming the shortcomings of existing blowout preventers that require large spaces and are too close to the wellhead, thus limiting manual operation and improving operational flexibility and safety. Moreover, through the coordinated control of the hydraulic cylinder and rotary drive mechanism, fully automated operation is achieved, significantly shortening the operation time for a single tubing string compared to existing technologies and improving overall well workover efficiency. 2. This utility model adopts an L-shaped combination design of vertical (support pipe + guide pipe) and horizontal (guide pipe + drain pipe) for the support return pipe, and realizes pipe turning through right-angle bends A and B respectively. This composite L-shaped structure cleverly utilizes the three-dimensional space around the wellhead, making the device structure more compact and avoiding motion interference with other components of the workover rig (such as hydraulic tongs and lifting clamps). On this basis, the lower end of the support pipe is connected to the center of the slewing bearing, ensuring the stability and concentricity of the entire device's slewing motion and effectively reducing swaying. The drain pipe introduces the liquid from the side of the blowout preventer into the support return pipe, forming a smooth and low-resistance drainage path, ensuring that the liquid can be quickly and completely guided into the liquid accumulation tank, upgrading from "able to drain" to "efficient drainage". 3. This invention integrates the drive unit and the support structure by hinged the hydraulic cylinder body to the mounting base of the guide pipe and the piston rod to the side of the rotating housing near the hinge, allowing the hydraulic cylinder to be directly mounted on the supporting return pipe, which serves as the main structure. This results in a compact structure with good rigidity. By arranging the hinge points of the hydraulic cylinder to form a force-saving and efficient lever system, a large housing closing torque can be generated with a small hydraulic cylinder thrust, ensuring that the rotating housing can close tightly and reliably, achieving effective sealing of the pipe coupling, and effectively reducing the load and component cost of the hydraulic system. 4. This invention adopts a combination of rotary motor and reducer to drive the rotary bearing design, which realizes the stable rotation of the support return pipe. The reducer can effectively reduce the speed and increase the torque, making the rotation angle of the blowout preventer adjustable to meet the different wellhead operation requirements. This modular design facilitates independent maintenance or replacement of the rotary drive mechanism, reducing downtime. By integrating the rotary motor and reducer on the workover rig platform, the clutter around the wellhead is effectively avoided, improving the safety of the operation. 5. This invention provides a guide ring at the top inner part of the blowout preventer, allowing the tubing to initially connect under the guidance of the guide ring. The interlocking liner seat and replaceable interlocking liner in the lower inner part of the blowout preventer further correct the male thread angle, reducing manual adjustments. The tight wrapping of the interlocking liner around the coupling effectively prevents liquid from spraying out of gaps, while also reducing wear and extending the liner's lifespan. The replaceable liner design supports different tubing specifications, improving the device's versatility. Attached Figure Description

[0012] Figure 1 This is a schematic diagram of the structure of the anti-spray device of this utility model; Figure 2 for Figure 1 A top view of the structure (omitting the rotary drive mechanism). Figure 3 This is a top view of the blowout preventer of this utility model in its working position (the rotary drive mechanism is omitted). Figure 4 This is a structural diagram showing the positions of the male and female couplings on the pipe column during the lifting and lowering of the blowout preventer of this utility model.

[0013] The components are as follows: 1. Blowout preventer; 101. Rotating housing; 1011. Locking strip; 102. Fixed housing; 1021. Locking groove; 2. Guide ring; 3. Interlocking inner liner seat; 4. Interlocking inner liner; 5. Hinge; 6. Support return pipe; 601. Guide pipe; 602. Support pipe; 603. Drain pipe; 604. Right angle bend A; 605. Right angle bend B; 7. Slewing bearing; 8. Slewing seat; 9. Slewing drive mechanism; 901. Slewing motor; 902. Reducer; 10. Hydraulic cylinder; 11. Mounting base. Detailed Implementation

[0014] The following embodiments are used to further illustrate the content of this utility model, and do not limit the application of this utility model. Example 1:

[0015] Please see Figures 1-4 This embodiment provides a rotary coupling blowout preventer, including a blowout preventer 1. The top inner part of the blowout preventer 1 is provided with a guide ring 2 that can guide the tubing string into the coupling liner 4 after the blowout preventer 1 is closed. The bottom inner part of the blowout preventer 1 is provided with a coupling liner seat 3, which serves as the mounting carrier for the coupling liner 4. The coupling liner 4 is installed in the coupling liner seat 3. The coupling liner 4 can be selected according to different specifications of tubing strings and is installed in the coupling liner seat 3. After the blowout preventer 1 is closed, the coupling liner 4 can effectively seal the coupling when the tubing is pulled up, preventing the liquid in the tubing string from splashing and guiding it to the liquid accumulation tank of the workover rig platform. When the tubing is lowered, the male coupling of the tubing string can be guided into the female coupling through the guide ring 2 and the inclined surface on the coupling liner 4, thus completing the coupling action of the tubing string. The blowout preventer 1 also includes a rotating housing 101 and a fixed housing 102 that can be opened and closed by a hinge 5, with both ends of the hinge 5 bridging and fixed to one end of the mating surface of the rotating housing 101 and the fixed housing 102.

[0016] A tubular support return pipe 6 is fixedly connected to the fixed housing 102, serving as a support for the entire device. The inner cavity of the support return pipe 6 is connected to the inner cavity of the blowout preventer 1, allowing the liquid in the tubing to be drained into the platform's liquid accumulation tank. The lower end of the support return pipe 6 is rotatably connected to a rotary seat 8 via a rotary bearing 7. A rotary drive mechanism 9 is provided on the side of the rotary seat 8, providing the rotary driving force for the entire blowout preventer. The output end of the rotary drive mechanism 9 is connected to the rotary bearing 7 and drives the support return pipe 6 to rotate through the rotary bearing 7. A hydraulic cylinder 10 is provided at the upper end of the support return pipe 6, providing the driving force for opening and closing the blowout preventer 1.

[0017] The support return pipe 6 includes a guide pipe 601 and a support pipe 602. The support pipe 602 and the guide pipe 601 are arranged in an L-shape in the vertical direction. One end of the guide pipe 601 is connected to the upper end of the support pipe 602 through a right-angle bend A604. The lower end of the support pipe 602 is connected to the upper center of the rotary bearing 7. The other end of the guide pipe 601 is connected to a drain pipe 603 through a right-angle bend B605. The drain pipe 603 and the guide pipe 601 are arranged in an L-shape in the horizontal direction. The end of the drain pipe 603 away from the guide pipe 601 is connected to the side wall of the fixed housing 102 away from the mating surface of the rotating housing 101. A mounting base 11 is fixed on the side wall of the guide pipe 601 near the drain pipe 603. The mounting base 11 is hinged to the cylinder body of the hydraulic cylinder 10, and the piston rod of the hydraulic cylinder 10 is hinged to the side wall of the rotating housing 101 near the hinge 5. Under the action of the hydraulic cylinder 10, the rotating housing 101 can form a closed space with the fixed housing 102, which plays a role in locking and preventing spraying.

[0018] The rotary drive mechanism 9 includes a rotary motor 901 and a reducer 902. The reducer 902 is connected to the output end of the rotary motor 901, which is fixed on the workover rig platform (the functions and structures of conventional equipment such as workover rig platforms are well known in the art, and the connection settings are also common knowledge, so they will not be described in detail here, nor are they shown in the attached drawings), and plays a fixed support role for the entire blowout preventer. The reducer 902 is fixed to the side of the rotary seat 8 and is connected to the rotary bearing 7 for transmission, so that the rotary motor 901 drives the support return pipe 6 to rotate around its own axis through the reducer 902 and the rotary bearing 7, thereby driving the blowout preventer 1 to rotate as a whole.

[0019] The working principle and usage process of this embodiment are as follows: Figures 1-4 As illustrated, after the rotary-type plug-in blowout preventer is assembled, the operator installs the entire blowout preventer on the workover rig platform. The purpose is to significantly improve the automation level and continuity of workover operations, solve the problem of the need for subsequent liquid cleaning in existing technologies, fundamentally reduce environmental pollution and workload, and overcome the shortcomings of existing blowout preventers that require high space requirements and are close to the wellhead, thus limiting manual operation. This improves the flexibility and safety of operations, realizes fully automated operation, and significantly shortens the operation time of a single tubing string compared to existing technologies, thereby improving the overall efficiency of workover.

[0020] Since both the rotary motor 901 and the hydraulic cylinder 10 are controlled by a controller (the functions and structures of controllers and other conventional equipment are well-known in the art, and the connection settings are also common knowledge, so they will not be described in detail here, nor are they shown in the accompanying drawings), when pipe pulling is required, the operator operates the controller to turn on the rotary motor 901. At this time, the entire support return pipe 6 (including the guide pipe 601, support pipe 602, drain pipe 603, and right-angle bends A604 and B605) will be driven by the rotary motor 901 to rotate the reducer 902 and the rotary bearing 7, which will move the closed blowout preventer 1 from the waiting position to the working position (i.e., the wellhead position). Since the rotating housing 101 is normally open when the blowout preventer 1 is in the initial position, after the blowout preventer 1 reaches the working position, the operator operates the controller to turn off the rotary motor 901, and then fastens the snap-fit ​​liner 4 inside the blowout preventer 1, which is located at the fixed housing 102, to the unscrewed pipe string coupling at the wellhead (e.g., ...). Figure 4 (As shown in the first figure), after the tubing coupling is fastened, the operating controller controls the hydraulic cylinder 10 to extend the piston rod. At this time, the rotating housing 101 will close under the extension of the piston rod, so that the locking strips 1011 at both ends of the mating surface of the rotating housing 101 will be locked into the locking grooves 1022 at both ends of the mating surface of the fixed housing 102. Then, the tubing is lifted by the external equipment, so that the male and female threads of the tubing are disengaged. At the same time, the oil-water mixture in the tubing will be drained sequentially through the drainage pipe 603, the right-angle bend B605, the guide pipe 601, the right-angle bend A604 and the support pipe 602 to the liquid accumulation tank of the workover rig platform. After the liquid is drained, the operating controller controls the hydraulic cylinder 10 to retract the piston rod, open the rotating housing 101 again, and release the tubing. Finally, the operating controller starts the rotary motor 901 again, so that the blowout preventer 1 returns from the working position to the waiting position under the rotation of the entire support return pipe 6 driven by the rotary motor 901, in preparation for the next operation.

[0021] When pipe laying operations are required, the operator activates the rotary motor 901 via the controller, causing the blowout preventer 1 to be moved from the waiting position to the working position under the rotation of the entire support return pipe 6 driven by the rotary motor 901. Upon reaching the working position, the rotary motor 901 is turned off. Subsequently, the snap-fit ​​liner 4 inside the blowout preventer 1, located at the fixed housing 102, is fastened to the pipe coupling (e.g., Figure 4 (As shown in the second figure), the hydraulic cylinder 10 is then controlled to extend the piston rod, the rotating housing 101 is closed, and then the tubing is lowered through the external equipment, so that the male thread of the tubing enters the blowout preventer 1 along the guide ring 2. The lowering continues, so that the male thread of the tubing passes through the coupling liner 4 and enters the coupling female thread, thus completing the alignment of the male and female threads. After alignment, the hydraulic cylinder 10 is controlled to retract the piston rod, the rotating housing 101 is opened, the tubing is released, and finally the controller is operated to start the rotary motor 901 again, so that the blowout preventer 1 returns from the working position to the waiting position under the rotation of the entire support return pipe 6 driven by the rotary motor 901, in preparation for the next operation. Example 2:

[0022] Please see Figures 1-4 As another objective of this utility model, a workover rig is provided, which includes the aforementioned rotary snap-fit ​​blowout preventer, with the rotary drive mechanism 9 of the rotary snap-fit ​​blowout preventer fixed to the workover rig platform. Therefore, the workover rig can achieve any of the beneficial effects of the guide rod gasket described above, which will not be elaborated further here.

Claims

1. A swivel type back-up blowout preventer comprising a blowout preventer cylinder having a back-up liner built therein, characterized in that, The blowout preventer includes a rotating housing and a fixed housing that can be opened and closed by a hinge. A tubular support return pipe is fixedly connected to the fixed housing. The inner cavity of the support return pipe communicates with the inner cavity of the blowout preventer. A hydraulic cylinder is provided at the upper end of the support return pipe. The piston rod of the hydraulic cylinder is hinged to the rotating housing. A rotary seat is rotatably connected to the lower end of the support return pipe through a rotary bearing. A rotary drive mechanism is provided on the side of the rotary seat. The output end of the rotary drive mechanism is connected to the rotary bearing and drives the support return pipe to rotate through the rotary bearing.

2. A swivel type back-up blowout preventer according to claim 1, wherein The support return pipe includes a guide pipe and a support pipe, and the support pipe and the guide pipe are arranged in an L-shape in the vertical direction.

3. A rotary snap-fit ​​anti-spray device according to claim 2, characterized in that, One end of the guide pipe is connected to the upper end of the support pipe through a right-angle bend A, and the other end of the guide pipe is connected to the drain pipe through a right-angle bend B. The drain pipe and the guide pipe are arranged in an L-shape in the horizontal direction. The lower end of the support pipe is connected to the upper center position of the rotary bearing.

4. A rotary snap-fit ​​anti-spray device according to claim 3, characterized in that, The end of the drainage tube away from the guide tube is connected to the side wall of the fixed housing away from the mating surface of the rotating housing.

5. A rotary snap-fit ​​anti-spray device according to claim 4, characterized in that, A mounting base is fixed on the side wall of the guide pipe near the drain pipe, and the mounting base is hinged to the cylinder body of the hydraulic cylinder.

6. A rotary snap-fit ​​anti-spray device according to claim 5, characterized in that, The piston rod of the hydraulic cylinder is hinged to the side wall of the rotating housing near the hinge.

7. A rotary snap-fit ​​anti-spray device according to claim 1, characterized in that, The rotary drive mechanism includes a rotary motor and a reducer. The reducer is connected to the output end of the rotary motor and is driven by the rotary bearing.

8. A rotary snap-fit ​​anti-spray device according to claim 7, characterized in that, The rotary motor drives the support return pipe to rotate around its own axis via a reducer and a rotary bearing, thereby causing the blowout preventer to rotate as a whole.

9. A rotary snap-fit ​​anti-spray device according to claim 1, characterized in that, The blowout preventer has a guide ring at its inner top and a snap-fit ​​liner seat at its inner lower part. The snap-fit ​​liner is installed inside the snap-fit ​​liner seat.

10. A well-servicing machine, characterized in that, Includes the rotary snap-fit ​​blowout preventer as described in any one of claims 1-9, wherein the rotary drive mechanism of the rotary snap-fit ​​blowout preventer is fixed to the workover rig platform.

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