A full-bore wellhead control device

Abstract

The present application provides a full-bore wellhead control device, including an upper joint, a lower joint, a center tube and a spring sleeve, wherein the lower end of the lower joint is provided with a mounting thread, the lower inner wall of the lower joint is provided with a second step inwardly, a blowout prevention valve plate and a torsion spring are provided on the horizontal mounting shaft, the blowout prevention valve plate abuts against the second step, the upper inner wall of the lower joint is provided with a third step inwardly, the third step is provided with a vertical mounting hole, a hydraulic cylinder system is provided in the vertical mounting hole, a hydraulic channel is provided in the vertical mounting hole, the hydraulic cylinder system is provided with a hydraulic plunger, the lower end of the center tube is slidably connected to the lower joint, the outer wall of the center tube is provided with a fourth step inwardly, the inner wall of the spring sleeve is provided with a fifth step inwardly, the fifth step is located below the fourth step, a pressure-bearing spring is provided between the two, the outer wall of the spring sleeve is provided with a sixth step inwardly, and the sixth step abuts against the hydraulic plunger. The present application simultaneously realizes the full-bore opening of the blowout prevention valve plate and the downhole safety valve, providing conditions for inserting cutting tools.

Description

Technical Field

[0001] The present application relates to the technical field of wellhead control devices, and in particular to a full-bore wellhead control device. Background Art

[0002] After the pressure test of the blowout preventer group of the oil well is completed, it is often encountered that the tool cannot be lifted smoothly. At this time, it is necessary to lower the cutting tool from the wellhead to perform the cutting operation. However, to lower the cutting tool, the downhole safety valve installed in the well must be opened to ensure that the pipe string reaches the full-bore state.

[0003] The opening and closing of the downhole safety valve is achieved through the hydraulic control pipeline joint installed at the tubing hanger. In order to successfully open the downhole safety valve, the blowout preventer group must be moved away or raised as a whole, and then the hydraulic control pipeline is connected to the drilling platform.

[0004] However, this method not only wastes a lot of time and reduces operating efficiency, but also leaves the wellhead open, increasing the operating risk. If the hydraulic control pipeline is connected to the drilling platform in advance, the hydraulic control pipeline will be held when the blowout preventer group is pressure tested, making it impossible to smoothly perform the pressure test operation. Based on this, the present application proposes a full-bore wellhead control device. Summary of the invention

[0005] The present application provides a full-bore wellhead control device, which can realize the connection between the oil outlet nozzle and the hydraulic control pipeline at the wellhead, and the operation is simple, convenient and fast. The blowout preventer valve plate is used to close the production pipe column, which can prevent accidents such as blowouts and ensure downhole safety. By pressing down the upper joint, the full-bore opening of the blowout preventer valve plate and the downhole safety valve can be realized at the same time, providing conditions for inserting the cutting tool, and the whole process is simple to operate.

[0006] In order to solve the above technical problems, this application adopts the following technical solutions:

[0007] A full-bore wellhead control device comprises an upper joint, a lower joint, a center tube and a spring sleeve, wherein the inner wall of the upper joint is provided with a first step inwardly, the inner wall of the first step is provided with an internal thread, the lower end of the lower joint is provided with a mounting thread, the lower inner wall of the lower joint is provided with a second step inwardly, a horizontal mounting shaft is provided at the second step, a blowout prevention valve plate and a torsion spring are provided on the horizontal mounting shaft, the blowout prevention valve plate abuts against the second step under the action of the torsion spring, the upper inner wall of the lower joint is provided with a third step inwardly, the third step is provided with a vertical mounting hole, a hydraulic cylinder system is provided in the vertical mounting hole, a hydraulic channel is provided in the vertical mounting hole, the hydraulic channel runs through the lower joint, the inner side of the hydraulic channel is communicated with the hydraulic cylinder system, the hydraulic An oil outlet nozzle is provided on the outside of the channel, and the hydraulic cylinder system is provided with a hydraulic plunger. An external thread is provided on the upper end of the center tube, and the external thread cooperates with the internal thread. The lower end of the center tube is slidably connected to the lower joint. A fourth step is provided inwardly on the outer wall of the center tube, and the spring sleeve is coaxially arranged outside the center tube. A fifth step is provided inwardly on the inner wall of the spring sleeve, and the fifth step is located below the fourth step, and a pressure spring is provided between the two. A sixth step is provided inwardly on the outer wall of the spring sleeve, and the sixth step abuts against the hydraulic plunger. When the center tube moves downward, the center tube can push open the anti-blowout valve plate, and the sixth step can push the hydraulic plunger, so that the hydraulic oil of the hydraulic cylinder system is discharged from the oil outlet nozzle.

[0008] During installation, the lower joint is coaxially installed on the tubing hanger at the wellhead through the installation thread, the interior of the lower joint is connected to the interior of the tubing hanger, and the oil outlet nozzle is connected to the hydraulic control pipeline of the downhole safety valve. When in use, the blowout prevention valve plate is tightly abutted against the second step under the action of the torsion spring, thereby blocking the lower joint, that is, the entire device is closed, the production string is closed, and the blowout prevention effect is played to ensure downhole safety. When it is necessary to put the cutting tool into the downhole, the operator can press down the upper joint, thereby driving the center pipe and the spring sleeve to move downward, the center pipe can push the blowout prevention valve plate until the blowout prevention valve plate is opened, and the full-bore opening is achieved. The spring sleeve can push the hydraulic plunger, so that the hydraulic oil is discharged from the hydraulic cylinder and enters the hydraulic channel, and finally enters the hydraulic control pipeline from the oil outlet nozzle, thereby realizing the opening of the hydraulic control pipeline and the opening of the downhole safety valve, providing the conditions for full-bore opening for the insertion of the cutting tool.

[0009] Compared with the existing technology, the full-bore wellhead control device can realize the connection between the oil outlet nozzle and the hydraulic control pipeline at the wellhead, which is simple, convenient and fast to operate. The blowout preventer valve plate can be used to close the production pipe string, which can prevent accidents such as blowouts and ensure downhole safety. By pressing down on the upper joint, the full-bore opening of the blowout preventer valve plate and the downhole safety valve can be achieved at the same time, providing conditions for inserting the cutting tool. The whole process is simple to operate.

[0010] In one embodiment of the present application, a seventh step is provided inwardly below the third step, a slide groove is provided on the inner wall of the seventh step, a protrusion is provided on the outer wall of the central tube, and the protrusion is slidably connected in the slide groove.

[0011] In one embodiment of the present application, the slide groove includes a first vertical segment, a semicircular segment and a second vertical segment, and both ends of the semicircular segment are connected to the lower ends of the first vertical segment and the second vertical segment.

[0012] In one embodiment of the present application, the lower joint is provided with a first limiting hole and a second limiting hole, and the second limiting hole is located below the first limiting hole;

[0013] The central tube is provided with a third limiting hole and a fourth limiting hole, wherein the fourth limiting hole is located above the third limiting hole and the central angle between the fourth limiting hole and the third limiting hole is equal to the central angle between the first vertical section and the second vertical section;

[0014] The spring sleeve is provided with a perforation;

[0015] When the protrusion is located at the upper end of the first vertical section, the first limiting hole, the through hole and the third limiting hole are opposite to each other and a limiting pin is provided through them;

[0016] When the protrusion is located at the upper end of the second vertical section, the second limiting hole, the through hole and the fourth limiting hole are opposite to each other and the limiting pin is passed through.

[0017] In one embodiment of the present application, the hydraulic cylinder system includes a hydraulic cylinder, a hydraulic spring, the hydraulic plunger and a piston. The hydraulic cylinder is arranged in the vertical mounting hole. An outlet is provided at the bottom of the hydraulic cylinder, and the outlet is connected to the hydraulic channel. The hydraulic spring is arranged in the hydraulic cylinder, the piston is arranged at the bottom of the hydraulic plunger, and the piston is slidably connected in the hydraulic cylinder.

[0018] In one embodiment of the present application, a wear-resistant sleeve is provided at the cylinder mouth of the hydraulic cylinder, and the hydraulic plunger is slidably connected in the wear-resistant sleeve.

[0019] In one embodiment of the present application, a pressure cap is provided at the upper end of the hydraulic plunger, and the sixth step abuts against the pressure cap.

[0020] In one embodiment of the present application, the upper joint is provided with a first sealing groove, the first sealing groove is provided with a first sealing ring, the lower joint is provided with a second sealing groove, and the second sealing groove is provided with a second sealing ring.

[0021] In one embodiment of the present application, a positioning step is provided outwardly below the external thread, and the positioning step abuts against the first step.

[0022] In one embodiment of the present application, a connecting thread is provided at the upper end of the upper joint, and the connecting thread is used to connect with other components. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] In order to more clearly illustrate the embodiments of the present application or the technical solutions in the prior art, a brief introduction will be given below to the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0024] Figure 1 A schematic diagram of the three-dimensional structure of a full-diameter wellhead control device provided in one embodiment of the present application;

[0025] Figure 2 A schematic diagram of a structure in which a full-bore wellhead control device provided in an embodiment of the present application is installed on a tubing hanger;

[0026] Figure 3 A schematic cross-sectional view of a full-bore wellhead control device provided in an embodiment of the present application, and in an unactivated state;

[0027] Figure 4 A schematic cross-sectional view of a full-bore wellhead control device provided in an embodiment of the present application, and in an activated state;

[0028] Figure 5 A schematic diagram of the three-dimensional structure of an upper joint used in a full-bore wellhead control device provided in an embodiment of the present application;

[0029] Figure 6 A schematic cross-sectional view of the upper joint used in the full-bore wellhead control device provided in one embodiment of the present application;

[0030] Figure 7 A schematic diagram of the three-dimensional structure of a lower joint used in a full-diameter wellhead control device provided in an embodiment of the present application;

[0031] Figure 8 A schematic cross-sectional view of a lower joint used in a full-bore wellhead control device provided in one embodiment of the present application;

[0032] Fig. 9 A schematic cross-sectional view of the lower joint in another direction used in the full-bore wellhead control device provided in one embodiment of the present application;

[0033] Fig.10 A schematic diagram of the three-dimensional structure of a central tube used in a full-bore wellhead control device provided in an embodiment of the present application;

[0034] Fig.11 A schematic cross-sectional view of a central tube used in a full-bore wellhead control device provided in one embodiment of the present application;

[0035] Fig.12 A schematic diagram of the three-dimensional structure of a spring sleeve used in a full-diameter wellhead control device provided in an embodiment of the present application;

[0036] Fig.13 A schematic cross-sectional view of a spring sleeve used in a full-diameter wellhead control device provided in an embodiment of the present application;

[0037] Fig.14 A schematic structural diagram of a hydraulic cylinder system used in a full-bore wellhead control device provided in one embodiment of the present application.

[0038] Reference numerals:

[0039] 010, tubing hanger; 020, downhole safety valve; 030, hydraulic control pipeline; 100, upper joint; 110, first step; 120, first sealing groove; 130, first sealing ring; 140, connecting thread; 200, lower joint; 210, mounting thread; 220, second step; 230, blowout preventer plate; 240, third step; 250, vertical mounting hole; 260, hydraulic channel; 270, oil outlet nozzle; 280, seventh step; 290, slide; 291, first vertical section; 292, semicircular section; 293, second vertical section; 300, first limit Hole; 310, second limiting hole; 320, second sealing groove; 330, second sealing ring; 350, hydraulic cylinder system; 351, hydraulic cylinder; 352, hydraulic spring; 353, hydraulic plunger; 354, piston; 355, outlet; 356, wear-resistant sleeve; 357, pressure cap; 400, center tube; 410, fourth step; 420, protrusion; 430, third limiting hole; 440, fourth limiting hole; 450, positioning step; 500, spring sleeve; 510, fifth step; 520, sixth step; 530, perforation; 600, pressure spring; 700, limiting pin. DETAILED DESCRIPTION

[0040] In order to make the purpose, technical scheme and advantages of the embodiments of the present application clearer, the technical scheme in the embodiments of the present application is clearly and completely described below. Obviously, the described embodiments are part of the embodiments of the present application, not all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in this field without creative work also fall within the scope of protection of the present application.

[0041] In the description of the present application, it should be understood that the terms "center", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", etc., indicating orientations or positional relationships, are based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as a limitation on the present application.

[0042] The terms "first" and "second" are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of the features. In the description of this application, unless otherwise specified, "plurality" means two or more.

[0043] In the description of this application, it should be noted that, unless otherwise clearly specified and limited, the terms "installed", "connected", and "connected" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection. For ordinary technicians in this field, the specific meanings of the above terms in this application can be understood according to specific circumstances.

[0044] First, let’s introduce the following nouns:

[0045] A subsurface safety valve (SSSV) is a downhole tool installed in an oil and gas well that can be closed urgently to prevent blowouts and ensure the safety of oil and gas well production in the event of a fire in the production facility, a pipeline rupture, or an irresistible natural disaster (such as an earthquake, ice conditions, and a strong typhoon).

[0046] The tubing hanger is a device that supports the tubing string and seals the annular space between the tubing and casing, and is generally installed at the wellhead.

[0047] The embodiment of the present application provides a full-bore wellhead control device, such as Figure 1 and Figure 2As shown, it is coaxially installed on the tubing hanger 010, which can achieve the sealing of the production tubing string and play a role in preventing blowout. When opened, it can achieve full-diameter opening to provide conditions for placing cutting tools.

[0048] like Figure 1 , Figure 2 , Figure 3 and Figure 4 As shown, the full-bore wellhead control device includes an upper joint 100, a lower joint 200, a center pipe 400 and a spring sleeve 500, wherein the upper joint 100 is located at the upper part and can be connected to other components above the entire device, the lower joint 200 is located at the lower part and is directly connected to the oil pipe hanger 010, and the center pipe 400 and the spring sleeve 500 are located between the upper joint 100 and the lower joint 200.

[0049] like Figure 5 and Figure 6 As shown, the upper joint 100 is a rotating body structure, and the inner wall of the upper joint 100 is provided with a first step 110 inwardly, and "inwardly" means that the first step 110 extends toward the center relative to the inner wall of the upper joint 100, that is, the inner diameter of the first step 110 is smaller than the inner diameter of the upper joint 100. The inner wall of the first step 110 is provided with an internal thread to provide installation conditions for threaded connection.

[0050] like Figure 7 As shown, the lower joint 200 is a rotating body structure, and a mounting thread 210 is provided at the lower end of the lower joint 200, and a corresponding thread is provided on the tubing hanger 010, and the two can be installed by threaded connection.

[0051] like Figure 8 and Fig. 9 As shown, the lower inner wall of the lower joint 200 is provided with a second step 220 inwardly, and a horizontal mounting shaft (not shown in the figure) is provided at the second step 220, and a blowout prevention valve plate 230 and a torsion spring (not shown in the figure) are provided on the horizontal mounting shaft, and the blowout prevention valve plate 230 is rotatably connected to the horizontal mounting shaft, and the blowout prevention valve plate 230 can abut against the second step 220 under the action of the torsion spring to achieve the upper and lower partition and closure of the lower joint 200. When the blowout prevention valve plate 230 is subjected to a downward force, it can overcome the force of the torsion spring and rotate downward to achieve the opening of the blowout prevention valve plate 230.

[0052] like Figure 3 , Figure 8 and Fig. 9As shown, the upper inner wall of the lower joint 200 is provided with a third step 240 inwardly, and the third step 240 is provided with a vertical mounting hole 250, and the vertical mounting hole 250 extends downward. A hydraulic cylinder system 350 is provided in the vertical mounting hole 250, and a hydraulic channel 260 is provided in the vertical mounting hole 250, and the hydraulic channel 260 runs through the lower joint 200. In other words, the hydraulic channel 260 is opened on the pipe wall of the lower joint 200. The inner side of the hydraulic channel 260 is communicated with the hydraulic cylinder system 350, and the outer side of the hydraulic channel 260 is provided with an oil outlet nozzle 270, and the oil outlet nozzle 270 is connected to the hydraulic control pipeline 030 of the downhole safety valve 020. The hydraulic cylinder system 350 is provided with a hydraulic plunger 353. When the hydraulic plunger 353 moves into the hydraulic cylinder 351, the hydraulic oil in the hydraulic cylinder 351 can be squeezed out, and the hydraulic oil enters the hydraulic channel 260.

[0053] like Figure 3 , Fig.10 and Fig.11 As shown, the upper end of the central tube 400 is provided with an external thread, which matches the internal thread of the upper joint 100, so that the central tube 400 can be coaxially installed in the upper joint 100, and the two can be understood as a whole. The lower end of the central tube 400 is slidably connected in the lower joint 200, so that the central tube 400 can move along the axial direction of the lower joint 200. The outer wall of the central tube 400 is provided with a fourth step 410 inwardly, and the outer diameter of the fourth step 410 is smaller than the outer diameter of the central tube 400.

[0054] like Figure 3 , Fig.12 and Fig.13 As shown, the spring sleeve 500 is coaxially arranged outside the central tube 400, and the inner wall of the spring sleeve 500 is provided with a fifth step 510 inwardly, and the fifth step 510 is located below the fourth step 410, and a pressure spring 600 is provided between the two, and the two ends of the pressure spring 600 are respectively abutted against the fourth step 410 and the fifth step 510. The outer wall of the spring sleeve 500 is provided with a sixth step 520 inwardly, and the outer diameter of the sixth step 520 is smaller than the outer diameter of the spring sleeve 500. The sixth step 520 abuts against the hydraulic plunger 353. In implementation, the length of the spring sleeve 500 can be longer, so that the spring sleeve 500 can extend into the upper joint 100, thereby covering the area between the upper joint 100 and the lower joint 200.

[0055] When the center pipe 400 moves downward, the lower end of the center pipe 400 contacts the blowout prevention valve plate 230 and gradually pushes the blowout prevention valve plate 230 until the blowout prevention valve plate 230 is pushed open, thereby achieving full-diameter opening of the lower joint 200. At the same time, the sixth step 520 pushes the hydraulic plunger 353, and the hydraulic plunger 353 squeezes the hydraulic oil in the hydraulic cylinder 351, so that the hydraulic oil is discharged from the oil outlet nozzle 270, and the hydraulic oil enters the hydraulic control pipeline 030.

[0056] During installation, the lower joint 200 is coaxially mounted on the tubing hanger 010 at the wellhead through the mounting thread 210. The interior of the lower joint 200 is connected to the interior of the tubing hanger 010, and the oil outlet nozzle 270 is connected to the hydraulic control pipeline 030 of the downhole safety valve 020. When in use, the blowout preventer plate 230 is tightly abutted against the second step 220 (such as Figure 3 As shown in the figure, this state can be called "unactivated state" or "closed state"), thereby blocking the lower joint 200, that is, the entire device is closed, the production string is closed, and the blowout prevention effect is achieved to ensure downhole safety. When it is necessary to put a cutting tool into the downhole, the operator can press down the upper joint 100, thereby driving the central pipe 400 and the spring sleeve 500 to move downward, and the central pipe 400 can push the blowout prevention valve plate 230 until the blowout prevention valve plate 230 is opened, realizing full-diameter opening (such as Figure 4 As shown in the figure, this state can be called the "excited state" or the "open state"), the spring sleeve 500 can push the hydraulic plunger 353, so that the hydraulic oil is discharged from the hydraulic cylinder 351, enters the hydraulic channel 260, and finally enters the hydraulic control pipeline 030 from the oil outlet nozzle 270, thereby realizing the opening of the hydraulic control pipeline 030 and the opening of the downhole safety valve 020, providing the full-bore opening condition for inserting the cutting tool.

[0057] Compared with the prior art, the full-bore wellhead control device can realize the connection between the oil outlet nozzle 270 and the hydraulic control pipeline 030 at the wellhead, which is simple, convenient and fast to operate. The blowout preventer plate 230 is used to close the production pipe string, which can prevent accidents such as blowouts and ensure downhole safety. By pressing down the upper joint 100, the full-bore opening of the blowout preventer plate 230 and the downhole safety valve 020 can be realized at the same time, providing conditions for inserting cutting tools, and the whole process is simple to operate.

[0058] In some embodiments, Fig. 9 and Fig.11 As shown, a seventh step 280 is provided inwardly below the third step 240, and the inner diameter of the seventh step 280 is smaller than the inner diameter of the third step 240. A slide groove 290 is provided on the inner wall of the seventh step 280. A protrusion 420 is provided on the outer wall of the central tube 400, and the protrusion 420 is slidably connected in the slide groove 290. The slide groove 290 and the protrusion 420 can guide and limit the sliding process of the central tube 400 relative to the lower joint 200. In implementation, two groups of slide grooves 290 can be provided on the inner wall of the seventh step 280 at an interval of 180 degrees, and are centrally symmetrically arranged, and two protrusions 420 are correspondingly provided on the outer wall of the central tube 400 at an interval of 180 degrees, so that the central tube 400 can slide more smoothly.

[0059] In some embodiments, Fig. 9 As shown, the chute 290 includes a first vertical section 291, a semicircular section 292, and a second vertical section 293. The two ends of the semicircular section 292 are connected to the lower ends of the first vertical section 291 and the second vertical section 293. That is, the first vertical section 291, the semicircular section 292, and the second vertical section 293 are generally connected to form a J shape, so that the shape of the entire chute 290 is generally J-shaped. In the unactivated state, the central tube 400 does not move downward, and the protrusion 420 is located at the top of the first vertical section 291. In the activated state, the protrusion 420 is located at the top of the second vertical section 293. In the process of changing from the unexcited state to the excited state, the center tube 400 is forced to move downward, squeezing the pressure spring 600, and the protrusion 420 moves downward along the first vertical section 291. When it reaches the semicircular section 292, the operator applies pressure and torque to the center tube 400 at the same time, so that the protrusion 420 can move along the semicircular section 292 and finally enter the second vertical section 293. The center tube 400 is released, and the protrusion 420 moves to the top of the second vertical section 293 under the rebound action of the pressure spring 600, so that the center tube 400 can remain fixed without being subjected to other forces, thereby achieving self-locking.

[0060] It should be noted that in this structure, a limit sleeve can be provided on the sixth step 520 of the spring sleeve 500. The limit sleeve is sleeved on the hydraulic plunger 353, so that the spring sleeve 500 can be kept fixed with the hydraulic plunger 353 in the circumferential direction, so that the spring sleeve 500 can only move up and down, thereby preventing the spring sleeve 500 from rotating when the center tube 400 rotates.

[0061] In some embodiments, Figure 8 , Fig.10 and Fig.13 As shown, the lower joint 200 is provided with a first limiting hole 300 and a second limiting hole 310, the second limiting hole 310 is located below the first limiting hole 300, and the distance between the two is equal to the distance between the upper end of the first vertical section 291 and the upper end of the second vertical section 293. The center tube 400 is provided with a third limiting hole 430 and a fourth limiting hole 440, the fourth limiting hole 440 is located above the third limiting hole 430, and the axial distance between the two is equal to the distance between the upper end of the first vertical section 291 and the upper end of the second vertical section 293. The central angle between the third limiting hole 430 and the fourth limiting hole 440 is equal to the central angle between the first vertical section 291 and the second vertical section 293, and the spring sleeve 500 is provided with a through hole 530, that is, the fourth limiting hole 440 and the third limiting hole 430 have both a distance interval in the axial direction and an angle interval in the circumferential direction.

[0062] like Figure 3As shown, when the entire device is in an unactivated state, that is, when the protrusion 420 is located at the upper end of the first vertical section 291, the first limiting hole 300, the through hole 530 and the third limiting hole 430 are opposite, and a limiting pin 700 is inserted, so that the central pipe 400 and the spring sleeve 500 can be fixed relative to the lower joint 200, and the movement of the central pipe 400 due to the dynamic pressure in the well or other uncertain factors can be avoided. In this case, before moving the central pipe 400, the limiting pin 700 should be pulled out first.

[0063] Similarly, if Figure 4 As shown, when the entire device is in an excited state, that is, when the protrusion 420 is located at the upper end of the second vertical section 293, the second limiting hole 310, the through hole 530 and the fourth limiting hole 440 are opposite to each other, and a limiting pin 700 is inserted therethrough, so that the central pipe 400 and the spring sleeve 500 can be fixed relative to the lower joint 200, and the movement of the central pipe 400 due to the dynamic pressure in the well or other uncertain factors can be avoided. In this case, before moving the central pipe 400, the limiting pin 700 should be pulled out first.

[0064] In some embodiments, Fig.14 As shown, the hydraulic cylinder system 350 includes a hydraulic cylinder 351, a hydraulic spring 352, a hydraulic plunger 353 and a piston 354. The hydraulic cylinder 351 is arranged in the vertical mounting hole 250. The hydraulic cylinder 351 is filled with hydraulic oil. An outlet 355 is arranged at the bottom of the hydraulic cylinder 351. The outlet 355 is communicated with the hydraulic channel 260. The hydraulic spring 352 is arranged in the hydraulic cylinder 351. The piston 354 is arranged at the bottom of the hydraulic plunger 353. The piston 354 is slidably connected in the hydraulic cylinder 351. In the process of the whole device changing from the unactivated state to the activated state, the piston 354 moves downward along the hydraulic cylinder 351, squeezes the hydraulic oil, and causes the hydraulic oil to be discharged from the outlet 355 of the hydraulic cylinder 351, enter the hydraulic channel 260, and finally enter the hydraulic control pipeline 030. In the process of the entire device changing from the excited state to the unexcited state, the piston 354 moves upward along the hydraulic cylinder 351, the squeezing force on the hydraulic oil becomes smaller, and the hydraulic oil gradually flows back from the hydraulic control pipeline 030 to the hydraulic cylinder 351.

[0065] In some embodiments, Fig.14 As shown, the cylinder mouth of the hydraulic cylinder 351 is provided with a wear-resistant sleeve 356, and the hydraulic plunger 353 is slidably connected in the wear-resistant sleeve 356. The wear-resistant sleeve 356 can withstand the friction of the hydraulic plunger 353, has less wear, longer service life, and reduces the number of replacement times.

[0066] In some embodiments, Fig.14As shown, a pressure cap 357 is provided at the upper end of the hydraulic plunger 353, and the sixth step 520 abuts against the pressure cap 357 to prevent the hydraulic plunger 353 from directly contacting the sixth step 520, thereby reducing wear and damage of the hydraulic plunger 353 and ensuring normal use of the hydraulic cylinder system 350.

[0067] In some embodiments, Figure 3 , Figure 6 and Fig. 9 As shown, the upper joint 100 is provided with a first sealing groove 120, and the first sealing groove 120 is provided with a first sealing ring 130, and the inner wall of the first sealing ring 130 can abut against the spring sleeve 500, so that the gap between the upper joint 100 and the spring sleeve 500 is blocked. The lower joint 200 is provided with a second sealing groove 320, and the second sealing groove 320 is provided with a second sealing ring 330, and the inner wall of the second sealing ring 330 can abut against the spring sleeve 500, so that the gap between the lower joint 200 and the spring sleeve 500 is blocked, so as to prevent the fluid from entering the spring sleeve 500, prevent the fluid from contacting the pressure spring 600, and prevent the pressure spring 600 from being corroded and damaged, thereby extending the service life of the pressure spring 600. In implementation, two first sealing grooves 120 and second sealing grooves 320 can be set in the axial direction, and two first sealing rings 130 and second sealing rings 330 are also set accordingly, so as to improve the actual sealing effect.

[0068] In some embodiments, Figure 6 , Fig.10 and Fig.11 As shown, a positioning step 450 is provided outwardly below the external thread of the center tube 400, the outer diameter of the positioning step 450 is larger than the size of the external thread, and the positioning step 450 abuts against the first step 110 to achieve the positioning of the center tube 400 along the axial direction of the upper joint 100, and to prevent the external thread from being excessively screwed into the upper joint 100 and causing damage to the external thread. During implementation, a sleeve-like component may also be provided between the positioning step 450 and the first step 110, which may also play a role in positioning and protecting the thread.

[0069] In some embodiments, Figure 6 As shown, the upper end of the upper joint 100 is provided with a connecting thread 140, and the connecting thread 140 can be connected with other components. For example, when the present application is applied to an offshore oil well, the upper joint 100 can be used to connect the upper oil pipe and open a well repair channel so that operators can lower well repair tools on the offshore drilling platform.

[0070] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present application, rather than to limit it. Although the present application has been described in detail with reference to the aforementioned embodiments, ordinary technicians in the field should understand that they can still modify the technical solutions recorded in the aforementioned embodiments, or replace some or all of the technical features therein with equivalents. However, these modifications or replacements do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present application.

Claims

1. A full-bore wellhead control device, characterized in that: include: An upper joint, wherein the inner wall of the upper joint is provided with a first step inwardly, and the inner wall of the first step is provided with an internal thread; A lower joint, wherein the lower end of the lower joint is provided with a mounting thread, a second step is provided inwardly on the lower inner wall of the lower joint, a horizontal mounting shaft is provided at the second step, a blowout prevention valve plate and a torsion spring are provided on the horizontal mounting shaft, the blowout prevention valve plate abuts against the second step under the action of the torsion spring, a third step is provided inwardly on the upper inner wall of the lower joint, a vertical mounting hole is provided in the third step, a hydraulic cylinder system is provided in the vertical mounting hole, a hydraulic channel is provided in the vertical mounting hole, the hydraulic channel runs through the lower joint, the inner side of the hydraulic channel is communicated with the hydraulic cylinder system, an oil outlet is provided on the outer side of the hydraulic channel, the hydraulic cylinder system comprises a hydraulic cylinder, a hydraulic spring, a hydraulic plunger and a piston, the hydraulic cylinder is arranged in the vertical mounting hole, an outlet is provided at the bottom of the hydraulic cylinder, the outlet is communicated with the hydraulic channel, the hydraulic spring is arranged in the hydraulic cylinder, the piston is arranged at the bottom of the hydraulic plunger, and the piston is slidably connected in the hydraulic cylinder; A central tube, wherein the upper end of the central tube is provided with an external thread, the external thread matches the internal thread, the lower end of the central tube is slidably connected to the lower joint, and the outer wall of the central tube is provided with a fourth step inwardly; A spring sleeve, the spring sleeve is coaxially arranged outside the central tube, the inner wall of the spring sleeve is provided with a fifth step inwardly, the fifth step is located below the fourth step, and a pressure-bearing spring is provided between the two, and the outer wall of the spring sleeve is provided with a sixth step inwardly, the sixth step abuts against the hydraulic plunger; When the central tube moves downward, the central tube can push open the anti-blowout valve plate, and the sixth step can push the hydraulic plunger to discharge the hydraulic oil of the hydraulic cylinder system from the oil outlet nozzle.

2. The full-bore wellhead control device according to claim 1, characterized in that: A seventh step is provided inwardly below the third step, a slide groove is provided on the inner wall of the seventh step, and a protrusion is provided on the outer wall of the central tube, and the protrusion is slidably connected in the slide groove.

3. The full-bore wellhead control device according to claim 2, characterized in that: The slide groove includes a first vertical section, a semicircular section and a second vertical section, and two ends of the semicircular section are connected to the lower ends of the first vertical section and the second vertical section.

4. The full-bore wellhead control device according to claim 3, characterized in that: The lower joint is provided with a first limiting hole and a second limiting hole, and the second limiting hole is located below the first limiting hole; The central tube is provided with a third limiting hole and a fourth limiting hole, wherein the fourth limiting hole is located above the third limiting hole and the central angle between the fourth limiting hole and the third limiting hole is equal to the central angle between the first vertical section and the second vertical section; The spring sleeve is provided with a perforation; When the protrusion is located at the upper end of the first vertical section, the first limiting hole, the through hole and the third limiting hole are opposite to each other and a limiting pin is provided through them; When the protrusion is located at the upper end of the second vertical section, the second limiting hole, the through hole and the fourth limiting hole are opposite to each other and the limiting pin is passed through.

5. The full-bore wellhead control device according to claim 1, characterized in that: The cylinder mouth of the hydraulic cylinder is provided with a wear-resistant sleeve, and the hydraulic plunger is slidably connected in the wear-resistant sleeve.

6. The full-bore wellhead control device according to claim 5, characterized in that: A pressure cap is provided at the upper end of the hydraulic plunger, and the sixth step abuts against the pressure cap.

7. The full-bore wellhead control device according to any one of claims 1 to 6, characterized in that: The upper joint is provided with a first sealing groove, the first sealing groove is provided with a first sealing ring, the lower joint is provided with a second sealing groove, the second sealing groove is provided with a second sealing ring.

8. The full-bore wellhead control device according to claim 7, characterized in that: A positioning step is provided outwardly below the external thread, and the positioning step abuts against the first step.

9. The full-bore wellhead control device according to claim 8, characterized in that: The upper end of the upper joint is provided with a connecting thread, and the connecting thread is used to connect with other components.

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