Low profile two-stage seal rotary preventer

Abstract

The application discloses a low-height two-stage sealing rotary blowout preventer, and solves the problems of large volume, high height, complex structure, high wellhead, inconvenient maintenance, and the need for a remote hydraulic control station for lubrication, cooling and pressure balance, resulting in large volume and high cost. The rotary blowout preventer comprises a shell assembly, a rotating body, a driving gland, a driving sleeve, an upper rubber cylinder, an annular compression ring, a lower rubber cylinder, a clamp device and a driving core. The upper rubber cylinder and the lower rubber cylinder are arranged in the rotating body, fully occupying the space of the rotating body, reducing the height of the rotary blowout preventer by half, making the rotary blowout preventer more suitable for a wider range of drilling platforms, and making the maintenance more convenient. Meanwhile, a threaded connection structure is adopted, high-temperature-resistant lubricating grease is injected into the installation chamber of the first bearing through the grease injection hole to realize the lubrication and cooling of the first bearing, so that the lubrication and cooling of the rotary blowout preventer do not need any external control unit, and the structure is simple, the operation is convenient, and the cost is low.

Description

Technical Field

[0001] This invention relates to a rotary blowout preventer, and more specifically to a low-profile, two-stage sealed rotary blowout preventer. Background Technology

[0002] Conventional drilling rotary blowout preventers (self-sealing type) use their own remote hydraulic control station to lubricate, cool, and balance the bearings and rotary seals inside the rotary seal body. This requires the installation of lubrication, cooling, and balancing pipelines between the rotary seal body and the remote hydraulic control station, resulting in a large size of the entire device, many control components, complex operation, and high cost.

[0003] Reference Figure 1 The existing dual-stage sealed rotary blowout preventer includes a housing assembly 01, a clamp and cylinder assembly 03, and a rotary seal assembly 02. The clamp and cylinder assembly 03 is located at the opening of the housing assembly 01, and the lower middle part of the rotary seal assembly 02 is inserted into the blowout preventer housing assembly 01. The rotary seal assembly 02 includes a rotary filler assembly 021, an upper rotary assembly 022, an upper rubber core 023, a lower rotary assembly 024, and a lower rubber core 025. The rotary filler assembly 021, the upper rotary assembly 022, the lower rotary assembly 024, and the lower rubber core 025 are connected sequentially from top to bottom, and the upper rubber core 023 is located inside the upper rotary assembly 022.

[0004] Because the upper rotating assembly 022 protrudes from the housing assembly 01 after installation, the height of the entire dual-stage sealed rotary blowout preventer is relatively large, approximately 2.2-2.5 meters. This makes operation and maintenance inconvenient after installation at the wellhead due to its excessive height. Summary of the Invention

[0005] The purpose of this invention is to solve the technical problems of existing dual-stage sealing rotary blowout preventers, which are large in size, tall in height, and have a complex structure, resulting in high wellheads, inconvenient maintenance, and the need for a remote hydraulic control station for lubrication, cooling and pressure balancing, leading to large size and high cost. The invention provides a low-profile dual-stage sealing rotary blowout preventer.

[0006] To achieve the above objectives, the technical solution provided by this invention is as follows:

[0007] A low-profile, two-stage sealed rotary blowout preventer, characterized by:

[0008] It includes a housing assembly, a rotating body, a drive cover, a drive sleeve, an upper glue cylinder, an annular pressure ring, a lower glue cylinder, a clamping device, and a drive compensation core;

[0009] The housing assembly has through holes along the vertical direction, and its lower end is connected to the blowout preventer or cross-connector at the wellhead via a connecting flange.

[0010] The rotating body is mounted on the upper end of the through hole of the housing assembly via the first bearing, and a grease injection hole is provided on the side wall of the housing assembly; the grease injection hole is connected to the mounting chamber of the first bearing and is used to inject high-temperature resistant grease to achieve lubrication and cooling of the first bearing;

[0011] An oil-water separation disc is provided at the lower outer circumferential surface of the rotating body where it mates with the housing assembly; the lower outer circumferential surface of the rotating body is sealed to the housing assembly by a primary high-pressure rotary seal assembly, and sealed to the oil-water separation disc by a secondary rotary seal ring.

[0012] The upper glue cylinder, the annular pressure ring, and the lower glue cylinder are installed inside the rotating body in sequence from top to bottom; the upper and lower ends of the annular pressure ring abut against the lower end of the upper glue cylinder and the upper end of the lower glue cylinder, respectively.

[0013] The drive cap is installed at the upper end of the rotating body, and its lower end abuts against the upper end of the upper glue cylinder;

[0014] The drive sleeve is mounted inside the clamping device via a second bearing; the lower end of the clamping device is mounted on the upper end of the housing assembly.

[0015] The lower end of the drive sleeve is installed on the upper end of the drive cover, and the upper end is outside the clamping device;

[0016] The drive core is attached to the upper end of the drive sleeve;

[0017] The upper and lower glue tubes and the drive core are each provided with square holes in the vertical direction to match the external square drill rod, so as to engage with the external square drill rod during use.

[0018] Furthermore, the clamping device includes a left clamp, a right clamp, a rotating shaft, a rotating shaft support, a locking mechanism, and two brackets;

[0019] One end of the left clamp and the right clamp are hinged by a pivot, and the other end is connected by a locking mechanism;

[0020] The lower ends of the left and right clamps are installed on the upper ends of the two brackets, and the rotating shaft is installed on the upper end of the rotating shaft support.

[0021] The lower inner circumferential surfaces of the left and right clamps respectively engage with the upper outer circumferential surface of the housing assembly; the two brackets and the pivot support are respectively installed on the outer circumferential surface of the housing assembly;

[0022] The drive sleeve is mounted on the inner circumferential surfaces of the left and right clamps via a second bearing.

[0023] Furthermore, the locking mechanism includes a locking rod and a locking sleeve;

[0024] One end of the locking rod is rotatably connected to the right clamp via a pin, and one end of the locking sleeve is rotatably connected to the left clamp via a rotating bearing and a hinge.

[0025] The other end of the locking rod is inserted into the other end of the locking sleeve and connected by threads.

[0026] Furthermore, the first bearing consists of three parts, including two load-bearing bearings and one support bearing;

[0027] The outer circumferential surface of the rotating body is provided with an annular boss;

[0028] The rotating ends of the first load-bearing bearing, the support bearing, and the second load-bearing bearing are installed sequentially from top to bottom on the outer circumferential surface of the rotating body. The lower side of the fixed end of the first load-bearing bearing abuts against the upper side of the fixed end of the support bearing. The lower side of the fixed end of the support bearing and the upper side of the fixed end of the second load-bearing bearing abut against the upper and lower ends of the annular boss, respectively.

[0029] There are two sets of grease injection holes, which are connected to the mounting chambers of the two load-bearing bearings respectively.

[0030] Furthermore, the upper end face of the rotating body is provided with multiple grooves along the circumferential direction;

[0031] The outer circumferential surface of the drive cover has multiple protrusions along the circumferential direction;

[0032] Multiple grooves correspond one-to-one with multiple protrusions and fit together. The drive cover and the rotating body are installed through the snap-fit ​​of multiple protrusions and multiple grooves.

[0033] Furthermore, the housing assembly includes an upper housing, a middle housing, and a lower housing connected sequentially from top to bottom;

[0034] The upper shell, middle shell and lower shell are each provided with through holes in the vertical direction, and the through holes of the three shells are interconnected to form a through hole;

[0035] The lower end of the lower casing is connected to the blowout preventer or large cross-connector at the wellhead via a connecting flange;

[0036] The rotating body is mounted in the through hole of the middle housing via the first bearing, and its upper and lower ends extend into the through holes of the upper and lower housings respectively; the grease injection hole is located on the side wall of the middle housing;

[0037] The oil-water separator is installed on the lower end face of the middle housing, and its lower end face abuts against the upper end face of the lower housing;

[0038] The lower outer circumferential surface of the rotating body is sealed to the lower housing by a primary high-pressure rotary sealing assembly.

[0039] Furthermore, the oil-water separator and the middle shell are provided with a first overflow hole and a second overflow hole that are connected to each other at one end;

[0040] The other end of the first overflow hole is connected to the space where the first-stage high-pressure rotary seal assembly and the second-stage rotary seal ring are installed through an annular groove set on the oil-water separator plate.

[0041] The other end of the second overflow hole penetrates the outer circumferential surface of the middle shell and is used to overflow well fluid in the event of failure of the first-stage high-pressure rotary seal assembly.

[0042] Furthermore, the primary high-pressure rotary seal assembly includes a spring seat, a preload spring, and a packing assembly;

[0043] One end of the preload spring abuts against the lower housing via a spring seat, and the other end abuts against one end of the packing assembly; the other end of the packing assembly abuts against the end face of the secondary rotary seal ring.

[0044] Compared with the prior art, the present invention has the following beneficial technical effects:

[0045] 1. This invention places both the upper and lower rubber sleeves within the rotating body, fully utilizing the space of the rotating body and reducing the height of the rotating blowout preventer by nearly half (approximately 1.3 meters). This makes it suitable for most high and low drilling rigs, broadening the applicable range of drilling platforms and facilitating maintenance. Furthermore, the first bearing of this invention is located within the mounting chamber of the housing assembly, which is separated from the pressure chamber inside the well. When inspecting the upper and lower rubber sleeves, it is only necessary to open the clamping device, then use the square drill pipe to lift or insert the upper and lower rubber sleeves and their axial accessories together, and then close the clamping device. There is no need to disassemble the housing assembly, making maintenance extremely convenient.

[0046] 2. The clamping device of the present invention abandons the existing hydraulic drive structure and adopts a threaded connection structure. At the same time, it can inject high-temperature resistant grease into the mounting cavity of the first bearing through the grease injection hole to achieve lubrication and cooling of the first bearing, thereby ensuring that the rotating blowout preventer does not require any external control unit. It has a simple structure, is easy to operate, and has low cost. Attached Figure Description

[0047] Figure 1 A schematic diagram of an existing two-stage rotating blowout preventer;

[0048] Figure 1 The markings are explained below:

[0049] 01-Housing assembly; 02-Rotary seal assembly; 021-Rotary manifold assembly; 022-Upper rotary assembly; 023-Upper rubber core; 024-Lower rotary assembly; 025-Lower rubber core; 03-Clamp and hydraulic cylinder assembly;

[0050] Figure 2 This is a front sectional view of an embodiment of the present invention;

[0051] Figure 3 for Figure 2 Enlarged view of section I;

[0052] Figure 4 This is a three-dimensional structural diagram of an embodiment of the present invention;

[0053] Figure 5 This is a side view of an embodiment of the present invention;

[0054] Figure 6 for Figure 5 View from direction A;

[0055] Figure 7 The following is a state diagram of the rubber sleeve when it is replaced in the embodiment of the present invention: (a) is a structural schematic diagram of the drive core, (b) is a schematic diagram of the cooperation between the drive cap, drive sleeve, rubber sleeve assembly and square drill rod, and (c) is a schematic diagram of the cooperation between the housing assembly, rotating body and clamping device.

[0056] Figure 8 This is a top view of the driving cap in an embodiment of the present invention;

[0057] Figure 9 for Figure 8 BB cross-sectional view;

[0058] Figure 10 This is a top view of the rotating body in an embodiment of the present invention;

[0059] Figure 11 for Figure 10 CC section view;

[0060] Figure 12 This is a three-dimensional structural diagram of the clamping device in an embodiment of the present invention;

[0061] Figure 13 This is a schematic diagram of the locking mechanism in an embodiment of the present invention.

[0062] Figures 2-13 The markings are explained below:

[0063] 001-Square drill pipe;

[0064] 1-Housing assembly, 101-Upper housing, 102-Middle housing, 103-Lower housing;

[0065] 2-Rotating body, 201-Groove;

[0066] 3-Drive gland, 4-Drive sleeve, 5-Upper glue cylinder, 6-Annular pressure ring, 7-Lower glue cylinder;

[0067] 8-Clamping device, 81-Left clamp, 82-Right clamp, 83-Rotating shaft, 84-Rotating shaft support seat, 85-Locking mechanism, 851-Locking rod, 852-Locking sleeve, 853-Pin, 854-Rotating bearing, 855-Hinge seat, 86-Bracket;

[0068] 9-Drive core;

[0069] 10-Guard ring, 11-Grease injection hole, 12-Oil-water separator;

[0070] 13-First-stage high-pressure rotary seal assembly, 131-Spring seat, 132-Preload spring, 133-Packing assembly;

[0071] 14-Secondary rotary seal ring, 15-Second bearing, 16-Load bearing, 17-Support bearing, 18-First overflow hole, 19-Second overflow hole, 20-Annular groove, 21-Connecting flange. Detailed Implementation

[0072] To make the objectives, advantages, and features of the present invention clearer, the present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments. Those skilled in the art should understand that these embodiments are merely used to explain the technical principles of the present invention and are not intended to limit the scope of protection of the present invention.

[0073] Reference Figures 2 to 6 This embodiment is a low-profile, dual-stage sealed rotary blowout preventer, which mainly includes a housing assembly 1, a rotating body 2, a drive cover 3, a drive sleeve 4, an upper glue cylinder 5, an annular pressure ring 6, a lower glue cylinder 7, a clamping device 8, and a drive compensation core 9.

[0074] Reference Figure 2 The rotating body 2 is disposed within the through hole of the housing assembly 1 and is sealed to the housing assembly 1 by a rotary seal. The upper rubber sleeve 5 and the lower rubber sleeve 7 are both installed inside the rotating body 2; the upper rubber sleeve 5 and the lower rubber sleeve 7 are respectively used to seal the annular space between the through hole of the square drill rod 001 and the inner wall of the through hole of the rotating body 2.

[0075] The aforementioned upper glue cylinder 5 and lower glue cylinder 7 are existing technologies and will not be described in detail here.

[0076] In other embodiments of the present invention, only one stage of the rubber sleeve may be installed as needed (when the well pressure is low), thus broadening the applicability.

[0077] Reference Figure 2 and Figure 4The housing assembly 1 includes an upper housing 101, a middle housing 102, and a lower housing 103 arranged sequentially from top to bottom. The lower housing 103 serves a circulation function. The upper housing 101 and the middle housing 102 form a mounting chamber for the first bearing, i.e., a bearing cavity, between themselves and the rotating body 2. The bearing cavity is filled with high-temperature resistant grease and does not require external lubricating oil or external coolant. The upper housing 101 and the middle housing 102 are connected by a first bolt. The upper housing 101, the middle housing 102, and the lower housing 103 are connected by a second long bolt. The lower end of the lower housing 103 is provided with a connecting flange 21 for connection to the blowout preventer or large four-way valve at the wellhead.

[0078] Reference Figure 2 , Figure 5 and Figure 6 The inner and outer walls of the rotating body 2 are stepped. The rotating body 2 is rotatably connected to the housing assembly 1 via two load-bearing bearings 16 and one support bearing 17. The two load-bearing bearings 16 and one support bearing 17 form the aforementioned first bearing, and are all installed in the bearing cavity to support the rotating body 2. An annular pressure ring 6 is disposed between the upper glue cylinder 5 and the lower glue cylinder 7, and abuts against both. The drive cover 3 is fitted onto the upper end of the rotating body 2. The upper end of the drive cover 3 is connected to the drive sleeve 4, and the drive sleeve 4 is engaged with the drive compensation core 9. The lower end of the drive cover 3 abuts against the upper end of the upper glue cylinder 5, and its outer circumferential surface is fitted with the inner wall surface of the rotating body 2. Thus, both the upper glue cylinder 5 and the lower glue cylinder 7 can rotate with the rotating body 2, avoiding relative rotation between the glue cylinders (upper glue cylinder 5 and lower glue cylinder 7) and the rotating body 2 and the square drill rod 001.

[0079] Specifically, refer to Figure 10 and Figure 11 The upper end of the rotating body 2 is provided with multiple circumferentially distributed grooves 201. (Refer to...) Figure 8 and Figure 9 The outer circumferential surface of the drive cover 3 is provided with multiple protrusions evenly distributed along the circumference. The positions of the multiple protrusions and the multiple grooves 201 are one-to-one, and their shapes and sizes are adapted to each other. The drive cover 3 and the rotating body 2 are fitted together by the snap-fit ​​cooperation of the multiple protrusions and the multiple grooves 201.

[0080] Continue to refer to Figure 2 The outer periphery of the drive sleeve 4 is sequentially provided with a second bearing 15, a protective ring 10, and a clamping device 8. The main function of the second bearing 15 is to provide support. The inner circumferential surface of the protective ring 10 is fitted with the fixed end of the second bearing 15, and the outer circumferential surface is held and pressed downward by the clamping device 8. The rotating end of the second bearing 15 is connected to the drive sleeve 4 and abuts against the drive cover 3. At the same time, the lower end of the clamping device 8 is in a concave-convex fit with the upper end of the upper housing 101, pressing the drive cover 3 and the rubber sleeve together.

[0081] Reference Figure 2 and Figure 7When the angular drill pipe 001 rotates, it will drive the drive filler core 9 and drive sleeve 4 to rotate. Since the drive sleeve 4 is connected to the drive pressure cap 3, and the drive pressure cap 3 is fitted with the rotating body 2, and the upper rubber sleeve 5 and lower rubber sleeve 7 both hold the angular drill pipe 001 tightly, when the angular drill pipe 001 rotates, it can drive the drive filler core 9, drive sleeve 4, pneumatic pressure cap, rotating body 2, upper rubber sleeve 5, annular pressure ring 6 and lower rubber sleeve 7 to rotate synchronously. In addition, when the pressure inside the well pushes the lower rubber sleeve 7 upward, the pressure is transmitted sequentially through the lower rubber sleeve 7, annular pressure ring 6, upper rubber sleeve 5, drive pressure cap 3, drive sleeve 4, second bearing 15, and clamping device 8 to the upper housing 101, preventing the upper rubber sleeve 5 and lower rubber sleeve 7 from being impacted and thrown out.

[0082] Since the first bearing of the rotary blowout preventer in this embodiment is located in the bearing cavity, which is separated from the pressure chamber in the well, when inspecting or replacing the rubber sleeve, it is only necessary to open the clamping device 8 and lift the rubber sleeve and its axial accessories together through the square drill rod 001, without disassembling the housing assembly 1, making inspection and installation very convenient.

[0083] Specifically, refer to Figure 12 and Figure 13 The clamping device 8 can be opened and closed by a hydraulic cylinder or manually. If a positive and negative screw structure is used, it can ensure that the whole device does not require any external hydraulic power.

[0084] The clamping device 8 specifically includes a left clamp 81, a right clamp 82, a rotating shaft 83, a rotating shaft support 84, two brackets 86, and a locking mechanism 85. The lower ends of the rotating shaft support 84 and the two brackets 86 are all connected to the outer wall of the upper housing 101. The upper end of the rotating shaft support 84 is connected to the rotating shaft 83, and the left clamp 81 and the right clamp 82 are hinged through the rotating shaft 83. The upper end face of the bracket 86 can support the left clamp 81 or the right clamp 82 when they move towards or away from each other, ensuring that the left and right halves of the clamping device 8 open and close horizontally.

[0085] A locking mechanism 85 is disposed between the left clamp 81 and the right clamp 82. The locking mechanism 85 includes a locking rod 851 and a locking sleeve 852. The right end of the locking rod 851 is rotatably connected to the right clamp 82 via a pin 853. The left end of the locking sleeve 852 is rotatably connected to the left clamp 81 via a rotating bearing 854 and a hinge 855. The left end of the locking rod 851 extends into the right end of the locking sleeve 852, and the two are connected by a thread. The locking sleeve 852 can rotate circumferentially, while the locking rod 851 can only move axially and cannot rotate circumferentially. Rotating the locking sleeve 852 in either the forward or reverse direction can close or open the left clamp 81 and the right clamp 82.

[0086] Reference Figure 2An oil-water separator 12 is provided between the middle housing 102 and the rotating body 2, and the oil-water separator 12 is connected to the lower end recess of the middle housing 102. An annular groove 20 is provided between the oil-water separator 12 and the lower housing 103, and the oil-water separator 12 can separate the bearing cavity and the well pressure cavity. The rotating body 2 is sealed to the lower housing 103 by a primary high-pressure rotary seal assembly 13, and sealed to the oil-water separator 12 by a secondary rotary seal ring 14. The secondary rotary seal ring 14 is located above the primary high-pressure rotary seal assembly 13. (Refer to...) Figure 3 The primary high-pressure rotary sealing assembly 13 includes a spring seat 131, a preload spring 132, and a packing assembly 133. One end of the preload spring 132 abuts against the lower housing 103 via the spring seat 131, and the other end abuts against one end of the packing assembly 133; the other end of the packing assembly 133 abuts against the end face of the secondary rotary sealing ring 14.

[0087] Reference Figure 3 The oil-water separator 12 and the middle shell 102 are provided with a first overflow hole 18 and a second overflow hole 19 that are interconnected. When the first-stage high-pressure rotary seal assembly 13 leaks or fails, the annular groove 20 is connected to the mounting cavity of the first-stage high-pressure rotary seal assembly 13 and the mounting cavity of the second-stage rotary seal ring 14, as well as the first overflow hole 18 and the second overflow hole 19. The leaked well fluid will eventually flow out from the second overflow hole 19, which makes it easy for operators to observe the failure of the first-stage high-pressure rotary seal assembly 13 in a timely manner.

[0088] Reference Figure 2 and Figure 3 The middle housing 102 has two sets of grease injection holes 11 that penetrate the side wall. Each set of grease injection holes 11 has at least one hole and they are evenly distributed along the circumference. The positions of the two sets of grease injection holes 11 correspond to the positions of the two load-bearing bearings 16. High-temperature grease can be injected through the two sets of grease injection holes 11 to achieve lubrication and cooling of the bearings.

[0089] The working principle of this embodiment is as follows:

[0090] When the rotary blowout preventer is in operation, the connecting flange 21 of the lower housing 103 is connected to the blowout preventer or the large cross-connector at the wellhead, serving as a support connection.

[0091] When pressurized fluid in the well pushes the lower rubber sleeve 7 upward, the pressure is transmitted sequentially through the lower rubber sleeve 7 to the annular pressure ring 6, the upper rubber sleeve 5, the drive pressure cap 3, and the second bearing 15. Since the second bearing 15 is pressed by the protective ring 10, and the protective ring 10 is held by the clamping device 8, which is held by the housing assembly 1, and the housing assembly 1 is connected to the blowout preventer or the large four-way valve at the wellhead, the lower rubber sleeve 7 and the upper rubber sleeve 5 can be prevented from being ejected.

[0092] When the square drill rod 001 rotates, it will drive the drive core 9 to rotate. Since the drive core 9 is engaged with the drive sleeve 4, it drives the drive sleeve 4 to rotate. The drive sleeve 4 is connected to the drive cover 3, which drives the drive cover 3 to rotate. The drive cover 3 is engaged with the rotating body 2, which drives the rotating body 2 to rotate, thus preventing relative rotation between the rubber tube and the rotating body 2.

[0093] The sealing performance of the primary high-pressure rotary sealing assembly 13 can be self-adjusted according to the well pressure. That is, initially, the pre-tightening spring 132 and the well fluid jointly assist in sealing the primary high-pressure rotary sealing assembly 13. When the well pressure increases, the well fluid pushes the spring seat 131 upward, pressing the packing assembly 133 to play a sealing role. As the well pressure increases, the pressing force becomes greater and greater, and the sealing performance becomes better and better.

[0094] When the primary high-pressure rotary seal assembly 13 fails, the well fluid flows sequentially through the radial gap between the rotating body 2 and the lower housing 103, the mounting cavity of the primary high-pressure rotary seal assembly 13, and the annular groove 20 between the oil-water separator 12 and the lower housing 103, finally flowing out from the second overflow hole 19. At this time, the oil-water separator 12 can prevent the well fluid from entering the bearing cavity and causing contamination. In other words, the seal is still effective at this time.

[0095] It should be noted that during the operation of the primary high-pressure rotary seal assembly 13, minor leakage can still serve to lubricate and cool the primary high-pressure rotary seal assembly 13 and does not affect normal operation. However, when the leakage is very large, the primary high-pressure rotary seal assembly 13 needs to be replaced.

[0096] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and are not intended to limit them. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features therein. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the present invention.

Claims

1. A low-profile, dual-stage sealed rotary blowout preventer, characterized in that: It includes a housing assembly (1), a rotating body (2), a drive cover (3), a drive sleeve (4), an upper glue cylinder (5), an annular pressure ring (6), a lower glue cylinder (7), a clamping device (8), and a drive compensation core (9); The housing assembly (1) has through holes in the vertical direction, and its lower end is connected to the blowout preventer or the four-way valve at the wellhead via a connecting flange (21). The rotating body (2) is mounted on the upper end of the through hole of the housing assembly (1) through the first bearing, and a grease injection hole (11) is provided on the side wall of the housing assembly (1); the grease injection hole (11) is connected to the mounting chamber of the first bearing and is used to inject high-temperature resistant grease to achieve lubrication and cooling of the first bearing; An oil-water separation disc (12) is provided at the lower outer circumferential surface of the rotating body (2) where it mates with the housing assembly (1); the lower outer circumferential surface of the rotating body (2) is sealed to the housing assembly (1) by a first-stage high-pressure rotary sealing assembly (13), and sealed to the oil-water separation disc (12) by a second-stage rotary sealing ring (14); The upper glue cylinder (5), the annular pressure ring (6), and the lower glue cylinder (7) are installed in the interior of the rotating body (2) from top to bottom; the upper and lower ends of the annular pressure ring (6) respectively abut against the lower end of the upper glue cylinder (5) and the upper end of the lower glue cylinder (7); The drive cap (3) is installed on the upper end of the rotating body (2), and its lower end abuts against the upper end of the upper glue cylinder (5); The drive sleeve (4) is installed inside the clamping device (8) via a second bearing (15); the lower end of the clamping device (8) is installed at the upper end of the housing assembly (1); The lower end of the drive sleeve (4) is installed on the upper end of the drive cover (3), and the upper end is placed outside the clamping device (8); The drive filler core (9) is snapped onto the upper end of the drive sleeve (4); The upper glue cylinder (5), lower glue cylinder (7) and drive core (9) are respectively provided with square holes in the vertical direction to match the external square drill rod (001), which are used to engage with the external square drill rod (001) during use.

2. The low-profile, dual-stage sealed rotary blowout preventer according to claim 1, characterized in that: The clamping device (8) includes a left clamp (81), a right clamp (82), a rotating shaft (83), a rotating shaft support (84), a locking mechanism (85), and two brackets (86); One end of the left clamp (81) and the right clamp (82) are hinged by a pivot (83), and the other end is connected by a locking mechanism (85); The lower ends of the left clamp (81) and the right clamp (82) are mounted on the upper ends of the two brackets (86), and the rotating shaft (83) is mounted on the upper end of the rotating shaft support (84); The lower inner circumferential surfaces of the left clamp (81) and the right clamp (82) respectively engage with the upper outer circumferential surface of the housing assembly (1); the two brackets (86) and the pivot support (84) are respectively installed on the outer circumferential surface of the housing assembly (1); The drive sleeve (4) is mounted on the inner circumferential surfaces of the left clamp (81) and the right clamp (82) via the second bearing (15).

3. The low-profile, dual-stage sealed rotary blowout preventer according to claim 2, characterized in that: The locking mechanism (85) includes a locking rod (851) and a locking sleeve (852); One end of the locking rod (851) is rotatably connected to the right clamp (82) via a pin (853), and one end of the locking sleeve (852) is rotatably connected to the left clamp (81) via a rotating bearing (854) and a hinge (855). The other end of the locking rod (851) is inserted into the other end of the locking sleeve (852) and connected by a thread.

4. The low-profile, dual-stage sealed rotary blowout preventer according to any one of claims 1-3, characterized in that: The first bearing consists of three bearings, including two load-bearing bearings (16) and one support bearing (17); The outer circumferential surface of the rotating body (2) is provided with an annular boss; The rotating ends of the first load-bearing bearing (16), the support bearing (17) and the second load-bearing bearing (16) are installed on the outer circumferential surface of the rotating body (2) from top to bottom. The lower side of the fixed end of the first load-bearing bearing (16) abuts against the upper side of the fixed end of the support bearing (17). The lower side of the fixed end of the support bearing (17) and the upper side of the fixed end of the second load-bearing bearing (16) abut against the upper and lower ends of the annular boss, respectively. The grease injection holes (11) are in two sets, which are respectively connected to the mounting chambers of the two load-bearing bearings (16).

5. The low-profile, dual-stage sealed rotary blowout preventer according to any one of claims 1-3, characterized in that: The upper end face of the rotating body (2) is provided with a plurality of grooves (201) along the circumferential direction; The outer peripheral surface of the drive cover (3) is provided with multiple protrusions along the circumferential direction; The multiple grooves (201) correspond one-to-one with the multiple protrusions and are adapted to each other. The drive cover (3) and the rotating body (2) are installed through the snap-fit ​​of the multiple protrusions and the multiple grooves (201).

6. The low-profile, dual-stage sealed rotary blowout preventer according to claim 1, characterized in that: The housing assembly (1) includes an upper housing (101), a middle housing (102), and a lower housing (103) connected sequentially from top to bottom; The upper shell (101), middle shell (102) and lower shell (103) are respectively provided with through holes in the vertical direction, and the through holes of the three are interconnected to form the through hole; The lower end of the lower housing (103) is connected to the blowout preventer or the four-way valve at the wellhead via a connecting flange (21); The rotating body (2) is installed in the through hole of the middle housing (102) through the first bearing, and its upper and lower ends extend into the through holes of the upper housing (101) and the lower housing (103) respectively; the grease injection hole (11) is provided on the side wall of the middle housing (102); The oil-water separator (12) is installed on the lower end face of the middle shell (102), and its lower end face abuts against the upper end face of the lower shell (103); The lower outer circumferential surface of the rotating body (2) is sealed to the lower housing (103) by the first-stage high-pressure rotary sealing assembly (13).

7. The low-profile, dual-stage sealed rotary blowout preventer according to claim 6, characterized in that: The oil-water separator (12) and the middle shell (102) are provided with a first overflow hole (18) and a second overflow hole (19) that are connected to each other at one end; The other end of the first overflow hole (18) is connected to the space where the first-stage high-pressure rotary seal assembly (13) and the second-stage rotary seal ring (14) are respectively through the annular groove (20) provided on the oil-water separator (12); The other end of the second overflow hole (19) penetrates the outer peripheral surface of the middle housing (102) and is used to overflow well fluid in the event of failure of the first-stage high-pressure rotary seal assembly (13).

8. The low-profile, dual-stage sealed rotary blowout preventer according to claim 6 or 7, characterized in that: The primary high-pressure rotary sealing assembly (13) includes a spring seat (131), a preload spring (132), and a packing assembly (133); One end of the preload spring (132) abuts against the lower housing (103) via the spring seat (131), and the other end abuts against one end of the packing assembly (133); the other end of the packing assembly (133) abuts against the end face of the secondary rotary seal ring (14).

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