Blowout preventer hoisting device of drilling platform

Abstract

The utility model relates to the technical field of drilling platform equipment, provides a blowout preventer hoisting device of a drilling platform, and aims to ensure the stability and synchronism in the hoisting process. The device comprises a bridge frame, a turning pulley block and a lifting appliance, synchronous lifting of four lifting ropes is achieved through complex pulley and lifting rope path design, and the risk that the blowout preventer inclines or twists is reduced. A hydraulic oil cylinder is installed on the bridge, a rear pulley block is installed at the rear fixed end, and a front pulley block is installed at the front free end. The lifting rope is connected with the front and rear pulley blocks through the turning pulley block to ensure synchronous lifting. The device is further provided with a sliding rail, so that the bridge slides in the Y-axis direction, and the flexibility is improved. And the angle design of the turning pulley can adapt to different hoisting requirements, and the hoisting precision is improved. The device effectively reduces potential safety hazards and protects the safety of equipment and personnel.

Description

Technical Field

[0001] This utility model belongs to the field of drilling platform equipment technology, specifically relating to a blowout preventer lifting device for drilling platforms. Background Technology

[0002] During drilling, when the formation pressure exceeds the bottom hole pressure, drilling fluid is pushed upwards along the water lines of the drill string. To protect the water hose from being damaged by the high pressure and to prevent drilling fluid from escaping from the drill string, an internal blowout preventer (BOP) is required. The BOP needs to be installed directly at the wellhead, which is usually located high on the drilling platform or at a specific location. Therefore, hoisting equipment is needed to accurately lift the BOP to the designated position.

[0003] During the hoisting process, existing blowout preventers (BOPs) typically use at least four steel wire ropes connected to the four corners of the BOP. It is difficult to maintain accurate synchronization of the four steel wire ropes in real time during the ascent or descent, resulting in inconsistent lifting and lowering speeds. This causes uneven tension on the BOP, leading to tilting or twisting during hoisting. In severe cases, it can cause wear or breakage of the hoisting ropes and traction ropes, causing the BOP to fall or swing, resulting in damage to the BOP itself and posing a threat to equipment and personnel on the drilling platform.

[0004] Ensuring a consistent lifting speed for the hoisting rope and minimizing the maximum tilt angle of the blowout preventer during lifting are pressing issues that need to be addressed. Utility Model Content

[0005] To address the problems existing in the background art, this utility model provides a blowout preventer lifting device for drilling platforms, which includes a bridge, a directional pulley block, and a lifting tool, wherein:

[0006] The cable tray is equipped with a hydraulic cylinder, the rear end of which is a fixed end; the fixed end is equipped with a rear pulley assembly, which includes four pulleys, namely rear pulley one, rear pulley two, rear pulley three and rear pulley four in sequence;

[0007] The hydraulic cylinder is equipped with a piston rod, the front end of which is a free end; a front pulley assembly is installed on the free end, which includes eight pulleys, namely front pulley one, front pulley two, front pulley three, front pulley four, front pulley five, front pulley six, front pulley seven and front pulley eight in sequence;

[0008] The cable tray and the lifting device are connected by a lifting rope. The lower end of the lifting rope is connected to the lifting device, and the upper end is connected to the rear pulley block and the front pulley block via a directional pulley block.

[0009] The reversing pulley block includes reversing pulley 1, reversing pulley 2, reversing pulley 3, reversing pulley 4, reversing pulley 5, reversing pulley 7, and reversing pulley 8, all mounted on the bridge frame.

[0010] The lifting ropes include a front lifting rope and a rear lifting rope; the front lifting rope is equipped with a first front lifting rope and a second front lifting rope, which are respectively connected to the two ends of the front end of the lifting device; the rear lifting rope is equipped with a first rear lifting rope and a second rear lifting rope, which are respectively connected to the two ends of the rear end of the lifting device; simultaneously:

[0011] The first front suspension rope is sequentially wound around the first front pulley, the first rear pulley, and the second front pulley and connected to the fixed end;

[0012] The second front suspension rope is sequentially wound around the front pulley eight, the rear pulley four, and the front pulley seven and connected to the fixed end;

[0013] The first rear suspension rope is sequentially wound around the front pulley three, the rear pulley two, and the front pulley four and connected to the fixed end;

[0014] The second rear suspension rope is successively wound around the front pulley six, the rear pulley three, and the front pulley five, and connected to the fixed end.

[0015] In the preferred embodiment, the first front suspension rope passes through the first and third directional pulleys in sequence, and is wound around the first front pulley, the first rear pulley, and the second front pulley, and connected to the fixed end; the second front suspension rope passes through the second and fourth directional pulleys in sequence, and is wound around the eighth front pulley, the fourth rear pulley, and the seventh front pulley, and connected to the fixed end; the first rear suspension rope passes through the seventh and fifth directional pulleys in sequence, and is wound around the third front pulley, the second rear pulley, and the fourth front pulley, and connected to the fixed end; the second rear suspension rope passes through the eighth and sixth directional pulleys in sequence, and is wound around the sixth front pulley, the third rear pulley, and the fifth front pulley, and connected to the fixed end.

[0016] In the preferred embodiment, a slide rail is also provided, and the cable tray and the slide rail are slidably connected along the Y-axis.

[0017] In the preferred embodiment, the central axis of the directional pulley seven is parallel to the plane containing the X and Y axes, and makes an angle α with the Z axis; the central axis of the directional pulley eight is parallel to the plane containing the X and Y axes, and makes an angle -α with the Z axis.

[0018] In the preferred embodiment, the angle between the central axis of the directional pulley five and the plane containing the X-axis and Y-axis is β; the angle between the central axis of the directional pulley six and the plane containing the X-axis and Y-axis is β.

[0019] In the preferred embodiment, the central axis of the third directional pulley is perpendicular to the plane containing the X and Y axes; the central axis of the fourth directional pulley is perpendicular to the plane containing the X and Y axes.

[0020] In the preferred embodiment, the central axis of the directional pulley seven is parallel to the plane containing the X and Y axes, and makes an angle γ with the Z axis; the central axis of the directional pulley eight is parallel to the plane containing the X and Y axes, and makes an angle -γ with the Z axis.

[0021] In the preferred scheme, α = 45°.

[0022] In the preferred scheme, 0 ≤ β ≤ 30°.

[0023] In the preferred scheme, 0 ≤ γ ≤ 30°.

[0024] The beneficial effects achieved by this utility model are as follows:

[0025] First, this utility model features a cleverly designed pulley system and hoisting rope path, ensuring the synchronous lifting and lowering of the four hoisting ropes (two front ropes and two rear ropes) during the hoisting process. This reduces the tilting or twisting of the blowout preventer caused by inconsistent hoisting speeds, avoids wear or breakage of the ropes due to uneven stress during hoisting, extends the service life of the ropes, reduces safety hazards caused by rope failures, ensures the stability and synchronization of the blowout preventer during hoisting, effectively reduces safety hazards caused by hoisting instability, and protects the equipment and personnel on the drilling platform.

[0026] Secondly, the angle of the central axis of the directional pulley was accurately designed, which enables the lifting device to adapt to the lifting requirements of different angles and directions, and allows the lifting rope to be accurately and smoothly wound on the front and rear pulley blocks, ensuring that the blowout preventer can be accurately lifted to the designated position and improving the lifting accuracy.

[0027] Third, this utility model is designed with a bridge and slide rail that are slidably connected along the Y-axis, which allows the entire hoisting device to move flexibly on the drilling platform, making it convenient to carry out hoisting operations in different positions and improving the flexibility and operability of the equipment. Attached Figure Description

[0028] Figure 1 This is an overall structural diagram of the present invention;

[0029] Figure 2 This utility model relates to the structure of the suspension rope connection. Figure 1 ;

[0030] Figure 3 This utility model relates to the rope connection structure. Figure 2 ;

[0031] Figure 4 The suspension rope connection structure of this utility model Figure 3 .

[0032] Numbering on the map:

[0033] 1. Cable tray; 2. Lifting device; 3. Front lifting rope; 31. First front lifting rope; 32. Second front lifting rope; 4. Rear lifting rope; 41. First rear lifting rope; 42. Second rear lifting rope; 5. Hydraulic cylinder; 6. Slide rail; 7. Fixed end; 71. Rear pulley one; 72. Rear pulley two; 73. Rear pulley three; 74. Rear pulley four; 8. Free end; 81. Front pulley one; 82. Front pulley two ; 83. Front pulley three; 84. Front pulley four; 85. Front pulley five; 86. Front pulley six; 87. Front pulley seven; 88. Front pulley eight; 9. Directional pulley group; 91. Directional pulley one; 92. Directional pulley two; 93. Directional pulley three; 94. Directional pulley four; 95. Directional pulley five; 96. Directional pulley six; 97. Directional pulley seven; 98. Directional pulley eight. Detailed Implementation

[0034] The technical solution of this utility model will be clearly and completely described below with reference to the accompanying drawings. In addition, the forms of the various structures described in the following embodiments are merely illustrative. This utility model is not limited to the structures described in the following embodiments. All other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this utility model.

[0035] Reference Figures 1-4 A blowout preventer lifting device for a drilling platform includes a cable tray 1, which is the main support structure of the entire lifting device, used to bear the weight of all other components and provide stable support.

[0036] The cable tray 1 is equipped with components such as hydraulic cylinder 5 and directional pulley block 9, and slides along the Y-axis through slide rail 6.

[0037] Hydraulic cylinder 5 is a key component providing power, controlling the lifting and lowering of the spreader 2 through the extension and retraction of its piston rod. It includes a fixed end 7 at the rear and a free end 8 at the front. The fixed end 7 is mounted on the bridge frame 1 and is equipped with a rear pulley assembly. The free end 8 is connected to the bridge frame 1 via a piston rod and is equipped with a front pulley assembly.

[0038] The pulley block, including the rear pulley block, consists of four pulleys: rear pulley 1 71, rear pulley 2 72, rear pulley 3 73, and rear pulley 4 74, used for guiding and changing the direction of the hoisting rope. It is installed on the fixed end 7 of the hydraulic cylinder 5.

[0039] The front pulley block, consisting of eight pulleys (front pulley 1 81, front pulley 2 82, front pulley 3 83, front pulley 4 84, front pulley 5 85, front pulley 6 86, front pulley 7 87, and front pulley 88), is also used for guiding and changing the direction of the hoisting rope. It is installed on the free end 8 of the hydraulic cylinder 5.

[0040] Lifting device 2 is the component that directly connects to and lifts the blowout preventer. It is connected to the cable tray 1 via four lifting ropes, two front lifting ropes 3 and two rear lifting ropes 4, to achieve the lifting function.

[0041] The lifting rope is a key component connecting the lifting device 2 and the cable tray 1, used to transmit lifting force. It includes a front lifting rope 3 and a rear lifting rope 4. The front lifting rope 3 is divided into a first front lifting rope 31 and a second front lifting rope 32, and the rear lifting rope 4 is divided into a first rear lifting rope 41 and a second rear lifting rope 42. The lower ends of the lifting ropes are connected to the front and rear ends of the lifting device 2, respectively. The upper ends pass through the directional pulley block 9, then are wound around the rear and front pulley blocks, and finally connected to the fixed end 7 of the hydraulic cylinder 5.

[0042] The directional pulley block 9 consists of eight directional pulleys: directional pulley 1 (91), directional pulley 2 (92), directional pulley 3 (93), directional pulley 4 (94), directional pulley 5 (95), directional pulley 6 (96), directional pulley 7 (97), and directional pulley 8 (98). These pulleys are used to change the direction of the suspension rope, ensuring that the rope is correctly and smoothly wound around the front and rear pulley blocks. Installed on the cable tray 1, the central axis direction of each directional pulley is arranged according to design requirements to achieve specific directional effects.

[0043] The slide rail 6 provides a sliding track for the cable tray 1, allowing the cable tray 1 to slide along the Y-axis, thereby adjusting the position of the lifting device. Slidingly connected to the cable tray 1, the cable tray 1 can move freely on the slide rail 6.

[0044] The cable tray 1 serves as the main support structure, on which the fixed end 7 of the hydraulic cylinder 5 is mounted and connected to the free end 8 via a piston rod. This connection allows the hydraulic cylinder 5 to be securely mounted on the cable tray 1, and its telescopic movement controls the lifting and lowering of the spreader 2.

[0045] The fixed end 7 of the hydraulic cylinder 5 is equipped with a rear pulley block, and the free end 8 is equipped with a front pulley block. This layout allows the lifting rope to be guided and redirected through the rear and front pulley blocks respectively, thereby achieving stable lifting of the lifting device 2.

[0046] The connection relationships between the lifting ropes, the lifting device 2, and each pulley are as follows: The front lifting rope 3 is provided with a first front lifting rope 31 and a second front lifting rope 32, which are respectively connected to the two ends of the front end of the lifting device 2; the rear lifting rope 4 is provided with a first rear lifting rope 41 and a second rear lifting rope 42, which are respectively connected to the two ends of the rear end of the lifting device 2; at the same time, the first front lifting rope 31 is sequentially wound around the first front pulley 81, the first rear pulley 71, and the second front pulley 82 and connected to the fixed end 7; the second front lifting rope 32 is sequentially wound around the eighth front pulley 88, the fourth rear pulley 74, and the seventh front pulley 87 and connected to the fixed end 7; the first rear lifting rope 41 is sequentially wound around the third front pulley 83, the second rear pulley 72, and the fourth front pulley 84 and connected to the fixed end 7; the second rear lifting rope 42 is sequentially wound around the sixth front pulley 86, the third rear pulley 73, and the fifth front pulley 85 and connected to the fixed end 7.

[0047] The first front suspension rope 31 passes through the first directional pulley 91 and the third directional pulley 93 in sequence, and is wound around the first front pulley 81, the first rear pulley 71 and the second front pulley 82 and connected to the fixed end 7; the second front suspension rope 32 passes through the second directional pulley 92 and the fourth directional pulley 94 in sequence, and is wound around the eighth front pulley 88, the fourth rear pulley 74 and the seventh front pulley 87 and connected to the fixed end 7; the first rear suspension rope 41 passes through the seventh directional pulley 97 and the fifth directional pulley 95 in sequence, and is wound around the third front pulley 83, the second rear pulley 72 and the fourth front pulley 84 and connected to the fixed end 7; the second rear suspension rope 42 passes through the eighth directional pulley 98 and the sixth directional pulley 96 in sequence, and is wound around the sixth front pulley 86, the third rear pulley 73 and the fifth front pulley 85 and connected to the fixed end 7.

[0048] The central axis of pulley seven 97 is parallel to the plane containing the X and Y axes, and makes an angle α with the Z axis; the central axis of pulley eight 98 is parallel to the plane containing the X and Y axes, and makes an angle -α with the Z axis. The central axis of pulley five 95 forms an angle β with the plane containing the X and Y axes; the central axis of pulley six 96 forms an angle β with the plane containing the X and Y axes. The central axis of pulley three 93 is perpendicular to the plane containing the X and Y axes; the central axis of pulley four 94 is perpendicular to the plane containing the X and Y axes. The central axis of pulley seven 97 is parallel to the plane containing the X and Y axes, and makes an angle γ with the Z axis; the central axis of pulley eight 98 is parallel to the plane containing the X and Y axes, and makes an angle -γ with the Z axis. In the preferred embodiment, α = 45°. 0 ≤ β ≤ 30°. 0 ≤ γ ≤ 30°.

[0049] The angles between the central axis and the Z-axis of the directional pulleys 7 and 8 are α and -α, respectively. This symmetrical design allows the suspension rope to maintain a stable guiding angle when passing through these two pulleys, reducing the problem of uneven rope tension or poor sliding caused by angular deviation.

[0050] By precisely setting the direction of the central axis of the directional pulley and its included angle, the path of the hoisting rope is optimized, unnecessary friction and resistance are reduced, thereby improving hoisting efficiency.

[0051] It has been verified that when α = 45°, 0 ≤ β ≤ 30°, and 0 ≤ γ ≤ 30°, these optimized angles further ensure the smoothness and efficiency of the suspension rope path.

[0052] This invention allows for the selection of different included angles, enabling the lifting device to adapt to lifting requirements at various angles and directions. When it is necessary to lift the blowout preventer to a specific angle or position, this can be achieved by adjusting the configuration of the pulley block, thereby improving the applicability and application range of the equipment.

[0053] This utility model discloses a blowout preventer (BOP) hoisting device for drilling platforms. Its main purpose is to ensure the stability and synchronization of the BOP during hoisting, preventing tilting or twisting during the process. The following is a detailed description of the device's operation:

[0054] Initial state:

[0055] The device is in a stationary state, and the bridge 1 is fixed to a certain position on the drilling platform via the slide rail 6.

[0056] The piston rod of hydraulic cylinder 5 is in the retracted state, and the lifting device 2 is suspended below, waiting to be hoisted into place for the blowout preventer.

[0057] Preparing for hoisting:

[0058] Secure the blowout preventer to spreader 2, ensuring a secure connection.

[0059] The operator activates hydraulic cylinder 5 via the control system to prepare for hoisting.

[0060] Lifting begins:

[0061] Hydraulic cylinder 5 begins to work, the piston rod gradually extends, driving the front pulley group to move forward.

[0062] Since the front pulley block is connected to the piston rod, changes in the position of the front pulley block will cause changes in the tension of the hoisting rope.

[0063] At the same time, the reversing pulley block 9 serves to change the direction of the hoisting rope, ensuring that the hoisting rope can be smoothly wound around the front pulley block and the rear pulley block.

[0064] The synchronous transmission path of the suspension rope is as follows:

[0065] The first front suspension rope 31 passes through the first directional pulley 91 and the third directional pulley 93 in sequence, changes direction, and is wrapped around the first front pulley 81, the first rear pulley 71 and the second front pulley 82, and finally connects to the fixed end 7.

[0066] The second front suspension rope 32 passes through the second directional pulley 92 and the fourth directional pulley 94 in sequence to change direction, and is wrapped around the eighth front pulley 88, the fourth rear pulley 74 and the seventh front pulley 87, and finally connected to the fixed end 7.

[0067] The first rear suspension rope 41 passes through the reversing pulley 7 97 and the reversing pulley 5 95 in sequence to change direction, and is wound around the front pulley 3 83, the rear pulley 2 72 and the front pulley 4 84, and finally connected to the fixed end 7.

[0068] The second rear suspension rope 42 passes through the reversing pulley 8 98 and the reversing pulley 6 96 in sequence, and is wound around the front pulley 6 86, the rear pulley 3 73 and the front pulley 5 85, and finally connected to the fixed end 7.

[0069] This complex rope path design ensures the synchronization of the four ropes during the hoisting process, reducing the risk of the blowout preventer tilting or twisting.

[0070] hoisting process:

[0071] As the piston rod of hydraulic cylinder 5 continues to extend, the spreader 2 and the blowout preventer gradually rise.

[0072] Throughout the hoisting process, operators need to closely monitor the tension changes of the hoisting ropes and the posture of the blowout preventer to ensure a smooth hoisting process.

[0073] If the hoisting position needs to be adjusted, it can be achieved by moving the drive bridge 1 along the Y-axis on the slide rail 6.

[0074] Hoisting completed:

[0075] When the blowout preventer is hoisted to the designated position, the operator stops the operation of hydraulic cylinder 5.

[0076] The piston rod of hydraulic cylinder 5 remains in its current position to prevent the blowout preventer from descending.

[0077] Operators can perform necessary checks and securing work to ensure the blowout preventer is securely installed at the wellhead.

[0078] Unloading and Resetting:

[0079] After the blowout preventer is installed, the operator can retract the piston rod of hydraulic cylinder 5 through the control system.

[0080] The spreader 2 and the blowout preventer gradually descend until they return to their initial positions.

[0081] The operator can disconnect the spreader 2 from the blowout preventer and prepare for the next lifting operation.

[0082] Throughout the hoisting process, the device achieved synchronous lifting and lowering of the hoisting ropes and stable hoisting of the blowout preventer through a complex pulley system and rope path design. Furthermore, the coordinated use of the slide rail 6 and hydraulic cylinder 5 provides the device with good flexibility and operability.

[0083] The above description is only a preferred embodiment of the present utility model and is not intended to limit the present utility model. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present utility model should be included within the protection scope of the present utility model.

Claims

1. A blowout preventer (BOP) lifting device for a drilling platform, characterized in that, It includes a cable tray (1), a reversing pulley block (9), and a lifting device (2), wherein: A hydraulic cylinder (5) is installed on the bridge (1), and the rear end of the hydraulic cylinder (5) is a fixed end (7); a rear pulley group is installed on the fixed end (7), which includes four pulleys, namely rear pulley one (71), rear pulley two (72), rear pulley three (73) and rear pulley four (74) in sequence. The hydraulic cylinder (5) is equipped with a piston rod, the front end of which is a free end (8); the free end (8) is equipped with a front pulley assembly, which includes eight pulleys, namely front pulley one (81), front pulley two (82), front pulley three (83), front pulley four (84), front pulley five (85), front pulley six (86), front pulley seven (87) and front pulley eight (88); The cable tray (1) and the lifting device (2) are connected by a lifting rope. The lower end of the lifting rope is connected to the lifting device (2), and the upper end is connected to the rear pulley block and the front pulley block via the reversing pulley block (9). The reversing pulley block (9) includes reversing pulley one (91), reversing pulley two (92), reversing pulley three (93), reversing pulley four (94), reversing pulley five (95), reversing pulley, reversing pulley seven (97) and reversing pulley eight (98) installed on the bridge frame (1); The lifting ropes include a front lifting rope (3) and a rear lifting rope (4); the front lifting rope (3) is provided with a first front lifting rope (31) and a second front lifting rope (32), the first front lifting rope (31) and the second front lifting rope (32) being connected to the two ends of the front end of the lifting device (2); the rear lifting rope (4) is provided with a first rear lifting rope (41) and a second rear lifting rope (42), the first rear lifting rope (41) and the second rear lifting rope (42) being connected to the two ends of the rear end of the lifting device (2); at the same time: The first front suspension rope (31) is wound around the first front pulley (81), the first rear pulley (71) and the second front pulley (82) in sequence and connected to the fixed end (7); The second front suspension rope (32) is wound around the front pulley eight (88), the rear pulley four (74) and the front pulley seven (87) in sequence and connected to the fixed end (7); The first rear suspension rope (41) is wound around the front pulley three (83), the rear pulley two (72) and the front pulley four (84) in sequence and connected to the fixed end (7); The second rear suspension rope (42) is wound around the front pulley six (86), the rear pulley three (73) and the front pulley five (85) in sequence and connected to the fixed end (7).

2. The blowout preventer lifting device for a drilling platform according to claim 1, characterized in that: The first front suspension rope (31) passes through the first directional pulley (91) and the third directional pulley (93) in sequence, and is wound around the first front pulley (81), the first rear pulley (71) and the second front pulley (82) and connected to the fixed end (7); the second front suspension rope (32) passes through the second directional pulley (92) and the fourth directional pulley (94) in sequence, and is wound around the eighth front pulley (88), the fourth rear pulley (74) and the seventh front pulley (87) and connected to the fixed end (7). The first rear suspension rope (41) is redirected by the seventh (97) and the fifth (95) directional pulleys in sequence, and is wound around the third (83), the second (72) and the fourth (84) directional pulleys in sequence and connected to the fixed end (7); the second rear suspension rope (42) is redirected by the eighth (98) and the sixth (96) directional pulleys in sequence, and is wound around the sixth (86), the third (73) and the fifth (85) directional pulleys in sequence and connected to the fixed end (7).

3. The blowout preventer lifting device for a drilling platform according to claim 1, characterized in that: It is also equipped with a slide rail (6), and the bridge (1) and the slide rail (6) are slidably connected along the Y-axis.

4. The blowout preventer lifting device for a drilling platform according to claim 1, characterized in that: The central axis of the directional pulley seven (97) is parallel to the plane containing the X and Y axes, and the angle between it and the Z axis is α; the central axis of the directional pulley eight (98) is parallel to the plane containing the X and Y axes, and the angle between it and the Z axis is -α.

5. The blowout preventer lifting device for a drilling platform according to claim 1, characterized in that: The angle between the central axis of the directional pulley five (95) and the plane containing the X-axis and Y-axis is β; the angle between the central axis of the directional pulley six (96) and the plane containing the X-axis and Y-axis is β.

6. The blowout preventer lifting device for a drilling platform according to claim 1, characterized in that: The central axis of the directional pulley three (93) is perpendicular to the plane containing the X and Y axes; the central axis of the directional pulley four (94) is perpendicular to the plane containing the X and Y axes.

7. The blowout preventer lifting device for a drilling platform according to claim 1, characterized in that: The central axis of the directional pulley seven (97) is parallel to the plane containing the X and Y axes, and the angle between it and the Z axis is γ; the central axis of the directional pulley eight (98) is parallel to the plane containing the X and Y axes, and the angle between it and the Z axis is -γ.

8. A blowout preventer lifting device for a drilling platform according to claim 4, characterized in that: α＝45°。 9. A blowout preventer lifting device for a drilling platform according to claim 5, characterized in that: 0≤β≤30°。 10. A blowout preventer lifting device for a drilling platform according to claim 7, characterized in that: 0≤γ≤30°.

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