A combined pressure device for fracturing wellheads

Abstract

This invention relates to the field of oilfield fracturing construction technology, specifically to a fracturing wellhead clamping device, comprising a housing and a tubing hanger disposed within the housing. Two upper gates and two lower gates are respectively disposed at the top and bottom of the housing. A stabilizing component is disposed between the upper and lower gates within the housing; the stabilizing component includes two stabilizing frames, on which a transmission component is mounted. By configuring stabilizing frames between the upper and lower gates, moving in the opposite direction to their movement, the upper and lower gates maintain stability relative to the tubing hanger after moving away from it, preventing swaying. When the upper and lower gates approach the tubing hanger, they retract and return to their original position between the upper and lower gates, thereby improving the stability of the tubing hanger. Furthermore, the upper and lower gates completely limit the movement of the tubing hanger, significantly enhancing its stability and facilitating subsequent fracturing operations.

Description

Technical Field

[0001] This invention relates to the field of oilfield fracturing construction technology, specifically to a pressure-combining device for fracturing wellheads. Background Technology

[0002] As oilfield development enters its mid-to-late stages, the number of polymer flooding and ternary composite flooding wells increases annually, leading to a continuous rise in formation pressure. This is particularly true for high-pressure, low-permeability reservoirs, where injection becomes difficult and well shut-in pressure reduction is slow. In some oil and water wells, pressure reduction to the level required for conventional fracturing operations can take three to six months. These wells cannot be subjected to timely fracturing operations according to geological requirements. Even after pressure reduction to meet conventional requirements, abnormally high pressure often prevents successful well completion. Following fracturing, the high pressure causes a large outflow of fluid and oil / water from the wellhead, and in some wells, tubing string bulges out. Fluid drainage and pressure reduction are necessary before and during tubing string tripping, often using tanker trucks. Transporting waste fluid to a wastewater treatment plant for processing is costly and time-consuming, significantly increasing the cost of single-well operations. Conventional well operations require open-top work during tubing string installation and removal, posing a risk of backflow of fluid and oil / water into the environment. Therefore, a live fracturing technology has been developed for this type of well construction. This technology integrates live fracturing operations, including installing the original well tubing, running the fracturing tubing, fracturing, installing the fracturing tubing, and running the completion tubing. Chinese patent application CN109854199A discloses a live fracturing controller, including a housing connected to a sealing locking gate and a positioning suspension gate. The sealing locking gate reciprocates to ensure tight sealing during fracturing operations. The annulus between the housing and the fracturing tubing hanger is sealed and the tubing annulus is isolated. The positioning suspension gate reciprocates to suspend the fracturing tubing hanger during fracturing operations. This patent solves the problem that the gate cannot suspend the fracturing tubing string and cannot seal the pressure of the high-pressure fluid from top to bottom during fracturing, thus preventing the completion of live fracturing operations through a combined pressure wellhead. However, it has the problem that the upper and lower gates cannot be synchronized. Chinese patent CN115807642B discloses an energy-saving combined pressure fracturing wellhead device, including a fracturing controller, a matching hydraulic flat valve and a fracturing injection head connected to the fracturing controller, and a matching tubing on the fracturing controller. The tubing hanger includes symmetrically arranged semi-sealed housings, each containing an upper gate and a lower gate. A drive frame is fixedly installed around the fracturing controller. The drive frame is used to synchronously advance the locking cylinders one and two on both sides of the semi-sealed housing during fracturing controller operation. This patent achieves synchronous movement of the two upper gates and two lower gates on both sides of the fracturing controller through independent drive of a single motor. However, in actual use, the tubing separator still has the problem of significant shaking during operation. When the upper and lower gates are aligned for clamping, the shaking may cause premature contact with the upper and lower gates, resulting in eccentricity during clamping. Summary of the Invention

[0003] To address the aforementioned problems, this invention provides a pressure-closing device for fracturing wellheads. This invention features a stabilizing frame positioned between the upper and lower gates, moving in the opposite direction to their respective motions. This stabilizes the upper and lower gates relative to the tubing hanger after they move away from it, preventing swaying. Conversely, as the upper and lower gates approach the tubing hanger, they retract and return to their original position, further enhancing the hanger's stability. The upper and lower gates also completely limit the tubing hanger's movement, significantly improving its stability and facilitating subsequent fracturing operations.

[0004] To address the problems of existing technologies, this invention provides a pressure-locking device for fracturing wellheads, comprising a housing and a tubing hanger disposed within the housing. Two upper gates and two lower gates are respectively disposed at the top and bottom of the housing, and both upper and lower gates can move relative to each other towards the tubing hanger. A stabilizing component for limiting the tubing hanger is disposed between the upper and lower gates within the housing. The stabilizing component includes two stabilizing frames that can slide relative to each other in a horizontal direction. A transmission component is disposed on the stabilizing frames to synchronously drive the upper and lower gates on the same side. The moving direction of the stabilizing frames is opposite to the moving direction of the lower gates of the upper and lower gates.

[0005] Preferably, each of the two stabilizers is provided with a clamping head that matches the tubing hanger on its opposite side, and the inner wall of each clamping head is provided with a plurality of balls arranged in a rectangular row.

[0006] Preferably, V-shaped slots and V-shaped blocks that match the V-shaped slots are respectively provided on the side walls of the two clamping heads.

[0007] Preferably, mounting brackets are provided on both sides of the housing. Two first connecting rods with hinged ends are provided between the end of the upper and lower gate plates away from the oil pipe hanger and the mounting bracket. The two first connecting rods on the upper and lower gate plates are arranged in a mirror symmetrical manner. The transmission component can synchronously drive the two first connecting rods on the upper and lower gate plates to fold and unfold.

[0008] Preferably, the transmission assembly includes two second connecting rods, one end of which is hinged to the stabilizer, and the other end of which is hinged to the hinge points of two first connecting rods on the upper and lower gate plates, respectively.

[0009] Preferably, the transmission assembly includes a lead screw and a first guide rod, which are parallel to each other and horizontally positioned between the mounting bracket and the housing. A stabilizer is sleeved on the lead screw and the first guide rod, with the stabilizer threadedly engaged with the lead screw and slidably engaged with the first guide rod.

[0010] Preferably, each of the two transmission components has a first synchronous pulley on its lead screw, and a second synchronous pulley connected to the first synchronous pulley by a synchronous belt is provided on the side of the first synchronous pulley. The second synchronous pulley is sleeved on the rotating shaft on the side of the housing. A rotary drive motor is provided between the rotating shafts of the two transmission components, and both rotating shafts are connected to the rotary drive motor for transmission.

[0011] Preferably, both the upper and lower gate plates are provided with sliding rods that can pass through the housing, and mounting plates are provided on the sliding rods. The top and bottom of the housing and the mounting frame are provided with two second guide rods, and the mounting plates of the upper and lower gate plates are respectively fitted onto the two second guide rods at the top and bottom of the mounting frame.

[0012] Preferably, a support shaft is provided at the middle of each of the two second connecting rods, and an elastic element is provided between the two support shafts.

[0013] Preferably, limit posts are provided at the ends of the lead screw and the first guide rod away from the oil pipe hanger, and sensors are provided on the stabilizer to monitor their movement distance.

[0014] The advantages of this invention compared to the prior art are:

[0015] 1. This invention provides a stabilizing frame between the upper and lower gate plates, which moves in the opposite direction to the upper and lower gate plates. This stabilizes the upper and lower gate plates as they move away from the tubing hanger, preventing them from swaying. When the upper and lower gate plates approach the tubing hanger, they retract and return to their original position between the upper and lower gate plates, thereby improving the stability of the tubing hanger. Furthermore, the upper and lower gate plates completely limit the movement of the tubing hanger, significantly enhancing its stability and facilitating subsequent fracturing operations.

[0016] 2. This invention utilizes the rolling of balls on the clamping heads to allow the tubing hanger to slide between the two clamping heads, thus not affecting the movement of the tubing hanger and facilitating subsequent clamping without hindering its operation. The V-shaped groove and V-shaped locking block design allows the V-shaped locking block to insert into the V-shaped groove when the two clamping heads abut against each other. The sliding process of the V-shaped locking block along the V-shaped groove helps to level the two clamping heads horizontally, preventing misalignment due to prolonged operation and thus avoiding eccentricity of the tubing hanger.

[0017] 3. In this invention, two second connecting rods respectively drive the hinge points of the two first connecting rods on the upper and lower gate plates to move. When the stabilizer moves away from the tubing hanger, the two second connecting rods on the stabilizer will push the hinge points of the two first connecting rods away from the stabilizer, thereby causing the two first connecting rods to unfold relative to each other. At the same time, the two second connecting rods will gradually change from the initial V-shape to the I-shape. After the second connecting rods are transformed into the I-shape, the two first connecting rods will also unfold into a straight line. At this time, the upper and lower gate plates keep the tubing hanger pressed against it. The unfolding of the second connecting rods can provide sufficient support for the unfolded two first connecting rods while maintaining pressure, thereby improving the stability of the equipment. Attached Figure Description

[0018] Figure 1 A schematic diagram of the three-dimensional structure of a pressure-combining device for fracturing wellheads. Figure 1 .

[0019] Figure 2 This is a front view of a hydraulic fracturing wellhead clamping device when the upper and lower gates are not clamped to the tubing hanger.

[0020] Figure 3 A schematic diagram of the three-dimensional structure of a pressure-combining device for fracturing wellheads. Figure 2 .

[0021] Figure 4 In a fracturing wellhead clamping device, the upper and lower gates clamp the tubing hanger.

[0022] Figure 5 This is a partial three-dimensional structural diagram of a stabilizing component in a pressure-closing device for a fracturing wellhead.

[0023] Figure 6 This is a schematic cross-sectional view of a pressure-combining device for a fracturing wellhead.

[0024] Figure 7 This is a schematic diagram of the three-dimensional cross-sectional structure of the shell in a fracturing wellhead pressurization device.

[0025] Figure 8 yes Figure 3 Enlarged view of point A in the middle.

[0026] Figure 9 yes Figure 5 Enlarged view of point B in the middle.

[0027] Figure 10 This is an exploded view of two clamping heads in a pressure-closing device for a fracturing wellhead.

[0028] The numbers on the map are:

[0029] 1-Housing; 11-Oil pipe hanger; 12-Upper gate; 121-Sliding rod; 122-Mounting plate; 123-Second guide rod; 13-Lower gate; 14-Mounting bracket; 141-First connecting rod; 2-Stabilizing assembly; 21-Stabilizing frame; 211-Clamping head; 212-Ball bearing; 213-V-shaped locking block; 214-V-shaped locking groove; 215-Sensor; 22-Transmission assembly; 221-Second connecting rod; 2211-Support shaft; 2212-Elastic element; 222-Screw screw; 2221-First synchronous pulley; 2222-Limiting post; 223-First guide rod; 224-Rotating shaft; 2241-Second synchronous pulley; 2242-Synchronous belt; 2243-Rotary drive motor. Detailed Implementation

[0030] To further understand the features, technical means, and specific objectives and functions achieved by the present invention, the present invention will be described in further detail below with reference to the accompanying drawings and specific embodiments.

[0031] like Figures 1 to 6 As shown: A fracturing wellhead pressure closing device includes a housing 1 and a tubing hanger 11 disposed within the housing 1. Two upper gates 12 and two lower gates 13 are respectively disposed at the top and bottom of the housing 1. The two upper gates 12 and two lower gates 13 can move relative to each other towards the tubing hanger 11. A stabilizing component 2 for limiting the tubing hanger 11 is disposed between the upper gates 12 and the lower gates 13 inside the housing 1. The stabilizing component 2 includes two stabilizing frames 21 that can slide relative to each other in the horizontal direction. A transmission component 22 for synchronously driving the upper gates 12 and the lower gates 13 on the same side is disposed on the stabilizing frame 21. The moving direction of the stabilizing frame 21 is opposite to the moving direction of the lower gates 13 of the upper gates 12.

[0032] After the upper gate 12 and lower gate 13 move away from the tubing hanger 11, the tubing hanger 11, being suspended within the wellbore, will sway within the wellhead. Although the synchronously moving upper gate 12 and lower gate 13 can stabilize the tubing hanger 11, if the swaying amplitude is too large, the upper gate 12 and lower gate 13 may prematurely contact one of the tubing hangers, causing eccentricity. To solve this problem, a stabilizing frame 21 is installed between the upper gate 12 and lower gate 13, moving in the opposite direction to their respective directions, so that the upper gate 12 and lower gate 13... After moving away from the tubing hanger 11, the stability of the tubing hanger 11 is maintained by the stabilizer 21 to prevent it from shaking. When the upper gate 12 and lower gate 13 approach the tubing hanger 11, they will retract and return to their original positions between the upper gate 12 and lower gate 13, thereby improving the stability of the tubing hanger 11. The upper gate 12 and lower gate 13 are used to prevent the tubing hanger 11 from rising and rotating, respectively. The tubing hanger 11 is first controlled by the stabilizing component 2, and then the tubing hanger 11 is completely limited by the upper gate 12 and lower gate 13. This can greatly improve the stability of the tubing hanger 11 and facilitate fracturing operations.

[0033] like Figure 3 , Figures 5 to 7 and Figure 10 As shown: On the opposite sides of the two stabilizers 21, there are clamping heads 211 that match the tubing hanger 11. On the inner wall of the two clamping heads 211, there are multiple balls 212 arranged in a rectangular row.

[0034] By setting the clamping heads 211 that match the tubing hanger 11, when the stabilizer 21 approaches the tubing hanger 11, the clamping heads 211 on the two stabilizer 21 can wrap around the tubing hanger 11 to keep it balanced. The two clamping heads 211 are preferably semi-circular arc-shaped structures. When the two clamping heads 211 abut against each other, they can form a circular hole that matches the tubing hanger 11. By setting multiple rectangularly arranged balls 212, the tubing hanger 11 will not be jammed during the clamping process of the clamping heads 211. Through the rolling of the balls 212, the tubing hanger 11 can slide between the two clamping heads 211, so as not to affect the movement of the tubing hanger 11, which is convenient for subsequent clamping and will not affect its operation.

[0035] like Figure 3 , Figures 5 to 7 and Figure 10 As shown: V-shaped slots 214 and V-shaped blocks 213 that match the V-shaped slots 214 are respectively provided on the side walls of the two clamping heads 211.

[0036] By setting up the V-shaped slot 214 and the V-shaped block 213, the V-shaped block 213 can be inserted into the V-shaped slot 214 when the two clamping heads 211 abut against each other. The sliding process of the V-shaped block 213 along the V-shaped slot 214 can level the two clamping heads 211 in the horizontal direction, preventing misalignment caused by prolonged operation and thus preventing the oil pipe hanger 11 from becoming eccentric. In this way, the position of the two clamping heads 211 can be corrected, improving the stability of the two clamping heads 211 for the oil pipe hanger 11. This makes the subsequent simultaneous clamping of the oil pipe hanger 11 by the upper gate 12 and the lower gate 13 more stable, improving the stability of the equipment.

[0037] like Figures 1 to 7 As shown: Mounting brackets 14 are provided on both sides of the housing 1. Two first connecting rods 141 with their ends hinged to each other are provided on the upper gate plate 12 and the lower gate plate 13 at the end away from the oil pipe hanger 11 and the mounting bracket 14. The two first connecting rods 141 on the upper gate plate 12 and the lower gate plate 13 are arranged in a mirror symmetrical manner. The transmission component 22 can synchronously drive the two first connecting rods 141 on the upper gate plate 12 and the lower gate plate 13 to fold and unfold.

[0038] Two first connecting rods 141 are hinged at their close ends, and their far ends are respectively hinged to the end of the upper gate plate 12 or the lower gate plate 13 and the mounting bracket 14. The transmission assembly 22 pushes the hinge point between the two first connecting rods 141, causing them to unfold and gradually change from a V-shape to a straight shape. This drives the upper gate plate 12 or the lower gate plate 13, which is hinged to the first connecting rods 141, towards the tubing hanger 11 until the upper gate plate 12 or the lower gate plate 13 clamps the tubing hanger 11. This method effectively clamps the tubing. The two upper gates 12 and two lower gates 13 maintain pressure to prevent the upper gates 12 or lower gates 13 from being blown open by backflowing gas or liquid, which helps to improve the stability of the equipment. The transmission assembly 22 pulls the hinge point between the two first connecting rods 141, causing the two first connecting rods 141 to retract, so that the two first connecting rods 141 can gradually change from a straight shape to a V shape, thereby driving the upper gates 12 or lower gates 13 hinged to the first connecting rods 141 away from the tubing hanger 11, until the upper gates 12 or lower gates 13 release the tubing hanger 11, thus completing the locking of the tubing hanger 11.

[0039] like Figures 1 to 7 and Figure 9As shown: The transmission assembly 22 includes two second connecting rods 221. One end of the two second connecting rods 221 is hinged to the stabilizer 21, and the other end of the two second connecting rods 221 is hinged to the hinge points of two first connecting rods 141 on the upper gate plate 12 and the lower gate plate 13, respectively.

[0040] The movement of the stabilizer 21 drives the two second connecting rods 221, which in turn drive the hinge points of the two first connecting rods 141 on the upper gate 12 and lower gate 13 to move. When the stabilizer 21 moves away from the oil pipe hanger 11, the two second connecting rods 221 on the stabilizer 21 push the hinge points of the two first connecting rods 141 away from the stabilizer 21, causing the two first connecting rods 141 to unfold relative to each other. Simultaneously, the two second connecting rods 221 gradually change from an initial V-shape to an I-shape. After the second connecting rods 221 change to an I-shape, the two first connecting rods 141 also unfold into a [missing information - likely a specific shape or configuration]. When the upper gate 12 and lower gate 13 are pressed against the tubing hanger 11, the tubing hanger 11 is moved in the opposite direction by moving the stabilizer 21. The two second connecting rods 221 on the stabilizer 21 gradually change from an I-shape to a V-shape. At this time, driven by the second connecting rods 221, the two first connecting rods 141 on the upper gate 12 or lower gate 13 also change from an I-shape to a V-shape. Thus, the transmission assembly 22 synchronously drives the upper gate 12 and lower gate 13 to move. At the same time, the unfolding of the second connecting rods 221 can provide sufficient support for the unfolded two first connecting rods 141 while maintaining pressure, thereby improving the stability of the equipment.

[0041] like Figures 1 to 8 As shown: The transmission assembly 22 includes a lead screw 222 and a first guide rod 223. The lead screw 222 and the first guide rod 223 are parallel to each other and horizontally positioned between the mounting bracket 14 and the housing 1. The stabilizer 21 is sleeved on the lead screw 222 and the first guide rod 223. The stabilizer 21 is threadedly engaged with the lead screw 222 and slidably engaged with the first guide rod 223.

[0042] By synchronously rotating the lead screws 222 of the two transmission components 22, the rotation of the lead screws 222 drives the stabilizer 21, which is threadedly engaged with them, to move. This causes the stabilizer 21 to slide along the axial direction of the first guide rod 223. Since the transmission components 22 on the two transmission frames are arranged in a mirror-symmetrical state, the two transmission frames can slide relative to each other along the axial direction of their respective first guide rods 223. Thus, the movement of the transmission frames drives the upper gate 12 and the lower gate 13 connected to them, so that the stabilized tubing hanger 11 can be locked by the upper gate 12 and the lower gate 13, improving the stability of the tubing hanger 11 and thus ensuring the stability during fracturing operations.

[0043] The self-locking characteristic of the lead screw 222 transmission ensures that the position of the stabilizer 21 remains fixed after adjustment, preventing slippage. This allows the second connecting rod 221 to better support the first connecting rod 141, enabling it to move while maintaining pressure and improving stability.

[0044] like Figures 3 to 9 As shown: Each of the two transmission components 22 has a first synchronous pulley 2221 on its lead screw 222. A second synchronous pulley 2241 is provided on the side of the first synchronous pulley 2221 and connected to it by a synchronous belt 2242. The second synchronous pulley 2241 is sleeved on the rotating shaft 224 on the side of the housing 1. A rotary drive motor 2243 is provided between the rotating shafts 224 of the two transmission components 22. Both rotating shafts 224 are connected to the rotary drive motor 2243.

[0045] The rotary drive motor 2243 is preferably a dual-head motor. The dual output shafts of the rotary drive motor 2243 drive the rotation shafts 224 of the two transmission components 22 to rotate. The rotation of the rotation shafts 224 drives the second synchronous pulley 2241 connected to it, which in turn drives the synchronous belt 2242. The rotation of the synchronous belt 2242 drives the first synchronous pulley 2221, which in turn drives the lead screw 222 connected to it to rotate. This causes the two transmission components 22 to rotate... The lead screw 222 can rotate synchronously. The rotation of the lead screw 222 of the two transmission components 22 drives the movement of the stabilizer 21 that is threaded with it, so that the stabilizer 21 can move along the first guide rod 223. The stabilizer 21 drives the second connecting rod 221, which in turn drives the two first connecting rods 141. The first connecting rods 141 drive the upper gate 12 and the lower gate 13 to move synchronously, so that the upper gate 12 and the lower gate 13 can clamp the oil pipe hanger 11 synchronously.

[0046] like Figures 3 to 7 As shown: Both the upper gate plate 12 and the lower gate plate 13 are provided with sliding rods 121 that can pass through the housing 1. The sliding rods 121 are provided with mounting plates 122. The housing 1 and the mounting frame 14 are provided with two second guide rods 123 at the top and bottom. The mounting plates 122 of the upper gate plate 12 and the lower gate plate 13 are respectively sleeved on the two second guide rods 123 at the top and bottom of the mounting frame 14.

[0047] The sliding rod 121 allows both the upper gate 12 and the lower gate 13 to slide on the housing 1. The mounting plate 122 and the two second guide rods 123 allow both the upper gate 12 and the lower gate 13 to slide along the axis of the second guide rods 123, thereby improving the smoothness of the sliding between the two upper gates 12 and the two lower gates 13 and facilitating the improvement of the stability when clamping the oil pipe hanger 11.

[0048] like Figures 3 to 7 and Figure 9 As shown: a support shaft 2211 is provided in the middle of each of the two second connecting rods 221, and an elastic element 2212 is provided between the two support shafts 2211.

[0049] By setting the support shaft 2211, both ends of the elastic element 2212 can be connected to the two second connecting rods 221 respectively, providing a connection platform. The elastic element 2212 makes the two second connecting rods 221 elastic in both expansion and contraction, so that when the stabilizer 21 moves, the two second connecting rods 221 will not fold at too small an angle, thus preventing the two first connecting rods 141 of the upper gate 12 or lower gate 13 from expanding or contracting. The elastic support of the elastic element 2212 can better drive the expansion and contraction of the two second connecting rods 221.

[0050] like Figures 3 to 7 and Figure 9 As shown: Limiting posts 2222 are provided at the ends of the lead screw 222 and the first guide rod 223 away from the oil pipe hanger 11, and a sensor 215 is provided on the stabilizer 21 to monitor its movement distance.

[0051] By setting the limit post 2222, the movement range of the stabilizer 21 can be controlled, preventing damage to the equipment due to excessive movement distance. The limit post 2222 has an elastic structure. When the stabilizer 21 moves to the limit position, the stabilizer 21 will abut against the limit post 2222. With the setting of the sensor 215, the stabilizer 21 can monitor its own movement distance. The monitored data will be sent to the back-end controller. The controller will then send an electrical signal to the stabilizer 21, so that the movement of the stabilizer 21 can be automatically adjusted, enabling the equipment to operate efficiently, improving the automation level of the equipment, and reducing the burden on the staff.

[0052] The above embodiments only illustrate one or more implementations of the present invention, and their descriptions are relatively specific and detailed, but they should not be construed as limiting the scope of the present invention. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of the present invention, and these all fall within the protection scope of the present invention. Therefore, the protection scope of the present invention should be determined by the appended claims.

Claims

1. A pressure-locking device for a fracturing wellhead, comprising a housing (1) and a tubing hanger (11) disposed within the housing (1), wherein two upper gates (12) and two lower gates (13) are respectively disposed at the top and bottom of the housing (1), and both the two upper gates (12) and the two lower gates (13) are movable relative to each other toward the tubing hanger (11); characterized in that, A stabilizing component (2) for limiting the oil pipe hanger (11) is provided inside the housing (1) between the upper gate (12) and the lower gate (13). The stabilizing component (2) includes two stabilizing frames (21) that can slide relative to each other in the horizontal direction. The stabilizing frame (21) is provided with a transmission component (22) that synchronously drives the upper gate (12) and the lower gate (13) on the same side. The moving direction of the stabilizing frame (21) is opposite to the moving direction of the lower gate (13) of the upper gate (12). Mounting brackets (14) are provided on both sides of the housing (1). Two first connecting rods (141) with hinged ends are provided between the end of the upper gate plate (12) and the lower gate plate (13) away from the oil pipe hanger (11) and the mounting bracket (14). The two first connecting rods (141) on the upper gate plate (12) and the lower gate plate (13) are arranged in a mirror symmetrical manner. The transmission assembly (22) can synchronously drive (2242) the two first connecting rods (141) on the upper gate plate (12) and the lower gate plate (13) to fold and unfold. The transmission assembly (22) includes two second connecting rods (221), one end of which is hinged to the stabilizer (21), and the other end of which is hinged to the hinge point of two first connecting rods (141) on the upper gate (12) and the lower gate (13), respectively. The transmission assembly (22) includes a lead screw (222) and a first guide rod (223). The lead screw (222) and the first guide rod (223) are parallel to each other and are horizontally positioned between the mounting bracket (14) and the housing (1). The stabilizer (21) is sleeved on the lead screw (222) and the first guide rod (223). The stabilizer (21) is threadedly engaged with the lead screw (222) and slidably engaged with the first guide rod (223). The lead screws (222) of the two transmission components (22) are each provided with a first synchronous pulley (2221). A second synchronous pulley (2241) is provided on the side of the first synchronous pulley (2221) and connected to it by a synchronous belt (2242). The second synchronous pulley (2241) is sleeved on the rotating shaft (224) on the side of the housing (1). A rotary drive motor (2243) is provided between the rotating shafts (224) of the two transmission components (22). Both rotating shafts (224) are connected to the rotary drive motor (2243) for transmission.

2. The pressure-closing device for a fracturing wellhead according to claim 1, characterized in that, Each of the two stabilizers (21) has a clamping head (211) that matches the tubing hanger (11) on its opposite side. Each of the two clamping heads (211) has multiple balls (212) arranged in a rectangular row on its inner wall.

3. The pressure-closing device for a fracturing wellhead according to claim 2, characterized in that, The two clamping heads (211) are respectively provided with V-shaped slots (214) and V-shaped blocks (213) that match the V-shaped slots (214).

4. The pressure-closing device for a fracturing wellhead according to claim 1, characterized in that, Both the upper gate (12) and the lower gate (13) are provided with sliding rods (121) that can pass through the housing (1). The sliding rods (121) are provided with mounting plates (122). The top and bottom of the housing (1) and the mounting frame (14) are provided with two second guide rods (123). The mounting plates (122) of the upper gate (12) and the lower gate (13) are respectively fitted onto the two second guide rods (123) at the top and bottom of the mounting frame (14).

5. The pressure-closing device for a fracturing wellhead according to claim 1, characterized in that, A support shaft (2211) is provided in the middle of each of the two second connecting rods (221), and an elastic element (2212) is provided between the two support shafts (2211).

6. The pressure-closing device for a fracturing wellhead according to claim 5, characterized in that, Limiting posts (2222) are provided at the ends of the lead screw (222) and the first guide rod (223) away from the tubing hanger (11), and a sensor (215) is provided on the stabilizer (21) to monitor its movement distance.

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