Seabed heave compensation anchoring device for deep-sea double-gradient drilling

Abstract

The invention discloses a seabed heave compensation anchoring device for deep-sea double-gradient well drilling, and relates to the technical field of ocean double-gradient well drilling construction technologies. The bottom of the lowering flange abuts against the top of the anchor barrel, the outer side wall of the lowering flange is connected with a release oil cylinder and an emergency oil cylinder, a hook claw is controlled through the release oil cylinder, and the hook claw tightly hooks the top flange of the anchor barrel. The emergency oil cylinder is connected with a wedge block capable of acting in the radial direction, and a lifting rod is connected into the lowering flange in a sliding mode and locked and positioned through the wedge block. The counterweight heave compensation rod is connected in the anchor cylinder in a sliding manner, and the top of the counterweight heave compensation rod is connected with the bottom end of the lifting rod through a steel wire rope; when the emergency separation working state needs to be started, the release oil cylinder and the emergency oil cylinder are controlled to unlock the anchor barrel and the lifting rod, and the anchor barrel and the balance weight heave compensation rod are abandoned. Multiple functions of the seabed heave compensation anchoring device are achieved, and meanwhile the seabed heave compensation anchoring device has the emergency release capacity and can be rapidly separated from the anchor cylinder and the balance weight heave compensation rod under the emergency condition.

Description

Technical Field

[0001] The present invention relates to the technical field of marine dual-gradient drilling construction technology, and more specifically, to a subsea heave compensation and anchoring device for deep-sea dual-gradient drilling. Background Art

[0002] The deep-sea dual-gradient drilling system is a solution for the recovery of drilling fluid in marine drilling, which can effectively solve the problems of pollution caused by direct discharge of drilling fluid into the sea and the large size of the hull and doubled operating costs due to the use of risers to recover drilling fluid. In this technology, conventional risers are not used in marine drilling, and the drill pipe is directly exposed to seawater. The subsea lift pump sends the drilling fluid containing cuttings in the wellhead suction module back to the drilling ship through the return pipe string.

[0003] As the return pipe string is the channel for the drilling fluid to return to the drilling ship, it needs to be positioned by an anchoring device on the seabed. The complex environment of marine drilling not only requires the device to provide firm positioning, but also to keep a certain distance from the wellhead to prevent collision with the wellhead suction module; to avoid the vertical heave of the ship caused by waves, it needs to have the function of compensating for the vertical heave of the return pipe string; at the same time, it also needs to have the ability of emergency release and be able to quickly disengage from the return pipe string in case of emergency.

[0004] When recovering the return pipe string, the anchoring device can pull out the anchor barrel from the mud for recycling; when it cannot be pulled out from the mud; or when a typhoon is coming and emergency evacuation is needed, the emergency release process can be started to discard components such as the anchor barrel and the counterweight rod to achieve rapid recovery.

[0005] Therefore, how to provide a subsea heave compensation and anchoring device for deep-sea dual-gradient drilling, since the components of the subsea heave compensation and anchoring device are heavy, for the convenience of offshore hoisting, lowering and recovery, improving construction efficiency and safety, and reducing construction costs and failure rates, is an urgent problem to be solved by those skilled in the art. Summary of the Invention

[0006] In view of this, the present invention provides a subsea heave compensation and anchoring device for deep-sea dual-gradient drilling, which can provide firm positioning, keep a certain distance from the wellhead to prevent collision with the wellhead suction module; avoid the vertical heave of the ship caused by waves, and needs to have the function of compensating for the vertical heave of the return pipe string; at the same time, it also needs to have the ability of emergency release and be able to quickly disengage from the return pipe string in case of emergency.

[0007] In order to achieve the above object, the present invention adopts the following technical solutions:

[0008] A subsea heave compensation and anchoring device for deep-sea dual-gradient drilling, comprising:

[0009] An anchor barrel;

[0010] Lower flange, the bottom of the lower flange abuts against the top of the anchor barrel, and a release oil cylinder and an emergency oil cylinder are connected to the outer side wall of the lower flange. A hook claw is controlled by the release oil cylinder, and the hook claw hooks the top flange of the anchor barrel; the emergency oil cylinder is connected with a radially movable wedge block, and a lifting rod is slidably connected in the lower flange, and the lifting rod is locked and positioned by the wedge block;

[0011] Counterweight heave compensation rod, the counterweight heave compensation rod is slidably connected in the anchor barrel, and the top of the counterweight heave compensation rod is connected to the bottom end of the lifting rod by a steel wire rope; when it is necessary to start the emergency disengagement working state, control the release oil cylinder to unlock the anchor barrel, and control the emergency oil cylinder to unlock the lifting rod to realize the abandonment of the anchor barrel and the counterweight heave compensation rod.

[0012] Through the above technical solutions, the present invention realizes various functions of the subsea heave compensation and anchoring device through the organic combination of components such as the anchor barrel, the lower flange, and the counterweight heave compensation rod. It can firmly position the upper return string to prevent it from colliding with the wellhead suction module, and can effectively compensate for the heave of the hull in the vertical direction, ensuring the stable progress of the drilling operation. At the same time, it has the ability of emergency disengagement, and can quickly disengage from the anchor barrel and the counterweight heave compensation rod in case of emergency, ensuring the safety of equipment and personnel, improving the construction efficiency and safety, and reducing the construction cost and failure rate.

[0013] Preferably, in the above-mentioned subsea heave compensation and anchoring device for deep-sea dual-gradient drilling, an underwater hydraulic unit for controlling the release oil cylinder and the emergency oil cylinder is installed on the lower flange. Installing the underwater hydraulic unit on the lower flange can directly and accurately control the actions of the release oil cylinder and the emergency oil cylinder underwater. This design enables the operator to unlock, lock and other operations on the anchoring device in a timely and accurate manner according to the actual operation requirements, improves the response speed and operation reliability of the device, and further enhances the adaptability and stability of the device in the complex marine environment.

[0014] Preferably, in the above-mentioned subsea heave compensation and anchoring device for deep-sea dual-gradient drilling, an underwater camera for monitoring the action of the hook claw is installed on the lower flange. The underwater camera installed on the lower flange can monitor the action of the hook claw in real time. The operator can intuitively understand the connection state between the hook claw and the top flange of the anchor barrel through the image transmitted by the camera, ensuring that the hook claw accurately and reliably hooks or releases the anchor barrel, avoiding potential safety hazards or operation errors caused by the improper action of the hook claw, and improving the visualization degree and safety of the operation.

[0015] Preferably, in the above-mentioned seabed heave compensation and anchoring device for deep-sea dual-gradient drilling, a limit pin and a guide pin are connected to the upper part of the anchor barrel. The limit pin is located below the guide pin. The limit pin is used to prevent the weight heave compensation rod from sliding out of the top of the anchor barrel, and the guide pin is used to prevent the steel wire rope from rubbing against the edge of the anchor barrel. The design of the limit pin and the guide pin at the upper part of the anchor barrel plays an important role in structural protection. The limit pin effectively prevents the weight heave compensation rod from sliding out of the top of the anchor barrel, ensuring the structural integrity of the device; the guide pin avoids the friction between the steel wire rope and the edge of the anchor barrel, reduces the wear of the steel wire rope, extends the service life of the steel wire rope, and also helps to maintain the normal operation of the device and reduce the maintenance cost.

[0016] Preferably, in the above-mentioned seabed heave compensation and anchoring device for deep-sea dual-gradient drilling, the bottom end of the lifting rod is connected to the steel wire rope through a first fixing pin and a shackle. The bottom end of the lifting rod is connected to the steel wire rope through a first fixing pin and a shackle. This connection method is firm and reliable and can withstand a large tensile force. In a complex marine environment, it ensures a stable connection between the steel wire rope and the lifting rod, avoiding device failures caused by loose or broken connections, and improving the reliability of the device during heave compensation and emergency release processes.

[0017] Preferably, in the above-mentioned seabed heave compensation and anchoring device for deep-sea dual-gradient drilling, the middle anchor barrel of the anchor barrel is connected to the lower anchor barrel through a second fixing pin, and the upper anchor tip at the bottom of the lower anchor barrel is connected to the lower anchor tip through a cutting pin. The middle anchor barrel is connected to the lower anchor barrel through a second fixing pin, and the upper anchor tip at the bottom of the lower anchor barrel is connected to the lower anchor tip through a cutting pin. This segmented connection structure not only ensures the overall stability of the anchor barrel but also facilitates the rapid separation of components by cutting the cutting pin when needed. This design can quickly discard the anchor barrel and the weight heave compensation rod during emergency release, improving the emergency response speed and operation flexibility of the device.

[0018] Preferably, in the above-mentioned seabed heave compensation and anchoring device for deep-sea dual-gradient drilling, a lower limit plate is fixed inside the upper anchor tip, and the lower limit plate is used to prevent the weight heave compensation rod from sliding out of the upper anchor tip. The lower limit plate fixed inside the upper anchor tip can effectively prevent the weight heave compensation rod from sliding out of the upper anchor tip. This design further enhances the structural stability of the device, ensuring that the weight heave compensation rod can maintain the correct position under various working conditions, avoiding device failures or safety accidents caused by component sliding out, and improving the safety and reliability of the device.

[0019] Preferably, in the above-mentioned subsea heave compensation and anchoring device for deep-sea dual-gradient drilling, a jumper hose connection flange is connected to the lowering flange. The jumper hose connection flange connected to the lowering flange provides the device with an extended connection function to other equipment or systems. Through the jumper hose connection flange, it is convenient to connect the anchoring device to other hydraulic systems, control systems, etc., to achieve more complex operation processes and function expansions, enhancing the versatility and adaptability of the device.

[0020] Preferably, in the above-mentioned subsea heave compensation and anchoring device for deep-sea dual-gradient drilling, a counterweight frame is fixed to the lowering flange. The counterweight frame fixed to the lowering flange can provide stable counterweight for the device. In the deep-sea environment, stable counterweight helps to maintain the balance and stability of the device, reduce the influence of factors such as ocean currents and waves on the device, improve the stability of the device during operation, and ensure the normal functioning of the heave compensation and anchoring functions.

[0021] Preferably, in the above-mentioned subsea heave compensation and anchoring device for deep-sea dual-gradient drilling, the lowering flange is connected to a riser string. Connecting the lowering flange to the riser string realizes the integrated integration of the anchoring device and the riser string. This design makes the entire drilling system more compact and coordinated, facilitating operation and management. At the same time, the integrated integration also helps to improve the overall performance and reliability of the system, reduce connection problems and failure risks caused by component separation, and improve the efficiency and safety of drilling operations.

[0022] Through the above technical solutions, compared with the prior art, the present invention discloses a subsea heave compensation and anchoring device for deep-sea dual-gradient drilling, which has the following beneficial effects:

[0023] 1. Improve operation stability and safety: Through the cooperation of the counterweight heave compensation rod and the steel wire rope, the vertical heave of the hull caused by factors such as sea waves is effectively compensated, ensuring that the riser string remains stable in a complex marine environment, guaranteeing the smooth return of the drilling fluid to the drilling ship, and maintaining the continuity and stability of the drilling operation. The device can firmly position the riser string and keep a certain distance from the wellhead suction module to prevent collision between the two, avoiding equipment damage and operation interruption caused by collision, and improving operation safety. In case of emergency, such as when the anchor barrel cannot be pulled out or an emergency evacuation is required during a typhoon, the anchor barrel and the counterweight heave compensation rod can be quickly released by controlling the release cylinder and the emergency cylinder, enabling the lowering flange, the counterweight frame, and the riser string to be quickly evacuated, ensuring the safety of equipment and personnel and reducing losses.

[0024] 2. Enhance operation reliability and convenience: The underwater hydraulic unit installed on the lowering flange can precisely control the actions of the release cylinder and the emergency cylinder, while the underwater camera can monitor the actions of the hook claws in real time. This enables the operator to intuitively and accurately grasp the operating state of the device, make timely operation adjustments, and improve the reliability and convenience of the operation. The lifting rod and the wire rope are connected through the first fixing pin and the shackle, and each component of the anchor barrel is connected through fixing pins, shear pins, etc. These connection methods are firm and reliable, can withstand large tensile forces and forces under complex working conditions, reduce faults such as component loosening and falling off, and ensure the normal operation of the device. The structural designs such as the limit pin, guide pin, and lower limit plate effectively prevent problems such as the sliding out of the counterweight heave compensation rod and the friction between the wire rope and the edge of the anchor barrel, protect the components of the device from damage, extend the service life, and at the same time ensure the structural stability and functional integrity of the device.

[0025] 3. Improve construction efficiency and economy: Each component of the device is heavy. Through reasonable design and optimized structure, it is convenient for offshore hoisting, lowering, and recovery operations, reduces hoisting time and input of manpower and material resources, and improves construction efficiency. When recovering the upper-return pipe string, the anchor barrel can be pulled out of the mud to realize the recovery and reuse of components, reducing construction costs. At the same time, the emergency release function can quickly abandon some components when necessary, ensure the safe evacuation of the main equipment, and reduce economic losses caused by equipment damage or loss. The device has good adaptability, can meet the requirements of deep-sea dual-gradient drilling operations under different depths and different geological conditions, reduce equipment adjustment and replacement caused by environmental changes, and improve equipment utilization rate and construction benefits.

[0026] 4. Enhance system integration and versatility: The lowering flange is connected to the upper-return pipe string to achieve the integrated integration of the anchoring device and the upper-return pipe string, making the entire drilling system more compact and coordinated, facilitating operation and management, and improving the overall performance and reliability of the system. The jumper hose on the lowering flange is connected to the flange, which provides convenience for the extended connection of the device to other equipment or systems, can realize more complex operation processes and function expansion, enhances the versatility and adaptability of the device, and meets the requirements of different drilling processes and operation scenarios. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] In order to more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the following will briefly introduce the drawings required for use in the description of the embodiments or the prior art. Obviously, the drawings in the following description are only the embodiments of the present invention. For those of ordinary skill in the art, other drawings can be obtained according to the provided drawings without creative efforts.

[0028] Figure 1 The drawings are the structural schematic diagrams of the subsea heave compensation and anchoring device for deep-sea dual-gradient drilling provided by the present invention;

[0029] Figure 2 The attached drawing is a schematic structural diagram of the lowering flange provided by the present invention;

[0030] Figure 3 The attached drawing is a sectional view of the lowering flange provided by the present invention;

[0031] Figure 4 The attached drawing is provided by the present invention Figure 3 an enlarged view of the partial A;

[0032] Figure 5 The attached drawing is a schematic diagram of the top of the anchor barrel provided by the present invention;

[0033] Figure 6 The attached drawing is provided by the present invention Figure 5 an enlarged view of the partial B;

[0034] Figure 7 The attached drawing is a schematic structural diagram of the anchor barrel provided by the present invention;

[0035] Figure 8 The attached drawing is a schematic structural diagram of the connection between the lower anchor tip and the upper anchor tip provided by the present invention;

[0036] Figure 9 The attached drawing is a schematic structural diagram of the emergency disengagement working state provided by the present invention;

[0037] Figure 10 The attached drawing is a construction process method diagram of the subsea heave compensation and anchoring device for deep - sea dual - gradient drilling provided by the present invention.

[0038] Wherein:

[0039] 1 - anchor barrel; 2 - counterweight heave compensation rod; 3 - steel wire rope; 4 - lowering flange; 5 - counterweight frame; 6 - return pipe string;

[0040] 101 - lower anchor tip; 102 - cutting pin; 103 - upper anchor tip; 104 - lower anchor barrel; 105 - lower limit plate; 106 - second fixing pin; 107 - middle anchor barrel;

[0041] 110 - wellhead clamping flange B; 111 - wellhead clamping flange A; 112 - limit pin; 113 - guide pin; 114 - lifting lug; 115 - auxiliary bogie frame; 117 - clamping flange C; 118 - clamping flange D;

[0042] 401 - hook claw; 402 - release oil cylinder; 403 - underwater hydraulic unit; 404 - underwater camera; 405 - first fixed pin shaft; 406 - movable pin; 407 - emergency oil cylinder; 408 - cross - connecting hose connection flange; 409 - lifting rod; 410 - wedge block; 411 - second fixed pin shaft; 412 - first fixing pin; 413 - shackle. Detailed implementation manners

[0043] The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without creative efforts shall fall within the protection scope of the present invention.

[0044] See the attached Figure 1 to the attached Figure 4 In the embodiments of the present invention, a subsea heave compensation and anchoring device for deep-sea dual-gradient drilling is disclosed, including:

[0045] An anchor barrel 1;

[0046] A lowering flange 4, the bottom of the lowering flange 4 abuts against the top of the anchor barrel 1, a release oil cylinder 402 and an emergency oil cylinder 407 are connected to the outer side wall of the lowering flange 4, a hook claw 401 is controlled by the release oil cylinder 402, and the hook claw 401 hooks the top flange of the anchor barrel 1; the emergency oil cylinder 407 is connected with a radially movable wedge block 410, a lifting rod 409 is slidably connected in the lowering flange 4, and the lifting rod 409 is locked and positioned by the wedge block 410;

[0047] A counterweight heave compensation rod 2, the counterweight heave compensation rod 2 is slidably connected in the anchor barrel 1, and the top of the counterweight heave compensation rod 2 is connected to the bottom end of the lifting rod 409 through a steel wire rope 3; when it is necessary to start the emergency disconnection working state, the release oil cylinder 402 is controlled to unlock the anchor barrel 1, and the emergency oil cylinder 407 is controlled to unlock the lifting rod 409 to realize the abandonment of the anchor barrel 1 and the counterweight heave compensation rod 2.

[0048] To further optimize the above technical solution, an underwater hydraulic unit 403 for controlling the release oil cylinder 402 and the emergency oil cylinder 407 is installed on the lowering flange 4.

[0049] To further optimize the above technical solution, an underwater camera 404 for monitoring the action of the hook claw 401 is installed on the lowering flange 4.

[0050] Further, in this embodiment, the hook claw 401 is connected to the lowering flange 4 through a second fixing pin shaft 411; the hook claw 401 is connected to the release oil cylinder 402 through a movable pin 406; the release oil cylinder 402 is connected to the lowering flange 4 through a first fixing pin shaft 405; the wedge block 410 can slide horizontally in the lowering flange 4; after the emergency oil cylinder 407 is fully retracted, the lifting rod 409 can slide up and down in the lowering flange 4.

[0051] See the attached Figure 5 and the attached Figure 6, a limit pin 112 and a guide pin 113 are connected to the upper part of the anchor barrel 1. The limit pin 112 is located below the guide pin 113. The limit pin 112 is used to prevent the counterweight heave compensation rod 2 from sliding out of the top of the anchor barrel 1, and the guide pin 113 is used to prevent the steel wire rope 3 from rubbing against the edge of the anchor barrel 1.

[0052] To further optimize the above technical solution, the bottom end of the lifting rod 409 is connected to the steel wire rope 3 through a first fixing pin 412 and a shackle 413.

[0053] See attached Figure 7 and attached Figure 8 , the middle anchor barrel 107 of the anchor barrel 1 is connected to the lower anchor barrel 104 through a second fixing pin 411. The upper anchor tip 103 at the bottom of the lower anchor barrel 104 is connected to the lower anchor tip 101 through a cutting pin 102 to form an anchor barrel pulling-out and shearing mechanism.

[0054] To further optimize the above technical solution, a lower limit plate 105 is fixed inside the upper anchor tip 103. The lower limit plate 105 is used to prevent the counterweight heave compensation rod 2 from sliding out of the upper anchor tip 103.

[0055] To further optimize the above technical solution, a jumper hose connection flange 408 is connected to the lowering flange 4.

[0056] To further optimize the above technical solution, a counterweight frame 5 is fixed on the lowering flange 4.

[0057] To further optimize the above technical solution, the lowering flange 4 is connected to an up-return pipe string 6.

[0058] See attached Figure 9 and attached Figure 10 , the construction process of the deep-sea dual-gradient drilling subsea heave compensation and anchoring device provided in this embodiment is as follows:

[0059] The wellhead clamping flange A111 and the wellhead clamping flange B110 are connected and fixed to the wellhead;

[0060] It is connected to the lifting lug 114 of the anchor barrel 1 through a sling, and the anchor barrel 1 is placed into the wellhead clamping flange hole; the counterweight heave compensation rod 2 is connected to the steel wire rope 3 through a fixed pin shackle;

[0061] The counterweight heave compensation rod 2 can slide up and down in the anchor barrel 1 by pulling the steel wire rope 3 with the lifting rod 409;

[0062] The wedge block 410 is connected to the emergency oil cylinder 407;

[0063] The underwater hydraulic unit 403 drives the emergency oil cylinder 407 to drive the wedge block 410 to clamp the lifting rod 409;

[0064] The lifting rod 409 is connected to the lowering flange 4 through the wedge block 410.

[0065] The auxiliary derrick car body 115 is installed and fixed on the auxiliary derrick (drilling equipment on ship).

[0066] The clamping flange C117 is connected to the clamping flange D118 and then to the auxiliary derrick car body 115.

[0067] Combined Figure 9 As shown in the figure, the specific lowering method is as follows: Lift the anchor barrel 1 to the wellhead by the drilling top drive sling and place it into the wellhead clamping flange; Use the top drive to lift the counterweight heave compensation rod 2 into the anchor barrel 1 and install the limit pin 112 and guide pin 113 of the counterweight heave compensation rod 2; Lift and lower the flange to the wellhead by the top drive sling, connect the lift and lower flange to the lifting rod 409, and drive the claw 401 to open and connect and lock with the anchor barrel 1 through the underwater hydraulic unit 403 of the lift and lower flange 4; Connect the return string 6 to the lift and lower flange 4 with the top drive, lift the return string 6, and remove the wellhead clamping flange; After installing and fixing the auxiliary derrick car body 115 on the auxiliary derrick on the ship; Lower the top drive and connect the return string 6, place the device on the auxiliary derrick car body 115, and install and symmetrically fix the clamping flange; Lift and rotate the counterweight frame 5 by the crane and fix it on the ship BOP derrick; Lift and remove the clamping flange on the auxiliary derrick car body 115 by the top drive, move the auxiliary derrick to the right out of the wellhead center, and lower the device with the top drive; The BOP derrick drags the counterweight frame 5 to the right to the wellhead center, connects and fixes the counterweight frame 5 to the lift and lower flange 4, and lower the device with the top drive and continuously connect the return string 6 until the anchor barrel 1 of the device enters the mud to the target depth; The underwater hydraulic unit 403 drives the release cylinder 402, and the release cylinder 402 drives the claw 401 to release the anchor barrel 1, and the top drive lifts the counterweight heave compensation rod 2 to the target position (the middle position of the anchor barrel) for dual-gradient drilling operations.

[0068] The specific recovery method: After connecting the return string 6 with the top drive and lowering it, rely on the gravity of the counterweight heave compensation rod 2 to pull the steel wire rope 3 to drive the lift and lower flange 4 to connect with the anchor barrel 1, and the underwater hydraulic unit 403 drives the release cylinder 402, and the release cylinder 402 drives the claw 401 to hook the anchor barrel 1 tightly; The top drive lifts the return string 6 to pull out the anchor barrel 1 from the seabed mud layer. If the pressure difference between the water pressure and the mud layer pressure is too large, the cut-off pin 102 is cut off, and the lower anchor tip 101 is separated from the upper anchor tip 103. When the water pressure is the same as the mud layer pressure at the anchor tip, the anchor barrel 1 is lifted smoothly.

[0069] Emergency release method: When the top drive cannot lift the return string 6 to pull out the anchor barrel 1 from the seabed mud layer, the underwater hydraulic unit 403 drives the release cylinder 402, and the release cylinder 402 drives the claw 401 to release the anchor barrel; While the top drive is lifting, the underwater hydraulic unit drives the emergency cylinder 407, and the emergency cylinder 407 drives the wedge block 410 to release the lifting rod 409, and the lifting rod 409 slides off, and the anchor barrel 1, the counterweight heave compensation rod 2, the steel wire rope 3 and the lifting rod 409 are discarded, realizing the evacuation of the lift and lower flange 4, the counterweight frame 5 and the return string 6.

[0070] The various embodiments in this specification are described in a progressive manner. Each embodiment focuses on the differences from other embodiments. For the same or similar parts among the embodiments, reference can be made to each other. For the apparatus disclosed in the embodiments, since it corresponds to the method disclosed in the embodiments, the description is relatively simple. For related parts, reference can be made to the description in the method section.

[0071] The above description of the disclosed embodiments enables those skilled in the art to implement or use the present invention. Various modifications to these embodiments will be obvious to those skilled in the art. The general principles defined herein can be implemented in other embodiments without departing from the spirit or scope of the present invention. Therefore, the present invention will not be limited to these embodiments shown herein, but rather to the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A subsea heave compensation and anchoring device for deep - sea dual - gradient drilling, characterized in that, Comprising: Anchoring cylinder (1); Lowering flange (4), the bottom of the lowering flange (4) abuts against the top of the anchoring cylinder (1), a release oil cylinder (402) and an emergency oil cylinder (407) are connected to the outer side wall of the lowering flange (4), a hook claw (401) is controlled by the release oil cylinder (402), and the hook claw (401) hooks the top flange of the anchoring cylinder (1); the emergency oil cylinder (407) is connected with a radially movable wedge block (410), a lifting rod (409) is slidably connected in the lowering flange (4), and the lifting rod (409) is locked and positioned by the wedge block (410); Counterweight heave compensation rod (2), the counterweight heave compensation rod (2) is slidably connected in the anchoring cylinder (1), and the top of the counterweight heave compensation rod (2) is connected to the bottom end of the lifting rod (409) through a steel wire rope (3); when it is necessary to start the emergency release working state, the release oil cylinder (402) is controlled to unlock the anchoring cylinder (1), and the emergency oil cylinder (407) is controlled to unlock the lifting rod (409) to realize the abandonment of the anchoring cylinder (1) and the counterweight heave compensation rod (2).

2. The seabed heave compensation and anchoring device for deep - sea dual - gradient drilling according to claim 1, characterized in that, An underwater hydraulic unit (403) for controlling the release oil cylinder (402) and the emergency oil cylinder (407) is installed on the lowering flange (4).

3. The subsea heave compensation and anchoring device for deep-sea dual-gradient drilling according to claim 1, wherein An underwater camera (404) for monitoring the action of the hook claw (401) is installed on the lowering flange (4).

4. The subsea heave compensation and anchoring device for deep - sea dual - gradient drilling according to claim 1, wherein, Limit pins (112) and guide pins (113) are connected to the upper part of the anchoring cylinder (1), the limit pins (112) are located below the guide pins (113), the limit pins (112) are used to prevent the counterweight heave compensation rod (2) from sliding out of the top of the anchoring cylinder (1), and the guide pins (113) are used to prevent the steel wire rope (3) from rubbing against the edge of the anchoring cylinder (1).

5. The subsea heave compensation and anchoring device for deep - sea dual - gradient drilling according to claim 1, wherein, The bottom end of the lifting rod (409) is connected to the steel wire rope (3) through a first fixing pin (412) and a shackle (413).

6. The seabed heave compensation and anchoring device for deep - sea dual - gradient drilling according to claim 1, characterized in that, The middle anchoring cylinder (107) of the anchoring cylinder (1) is connected to the lower anchoring cylinder (104) through a second fixing pin (411), and the upper anchor tip (103) at the bottom of the lower anchoring cylinder (104) is connected to the lower anchor tip (101) through a cutting pin (102).

7. The seabed heave compensation and anchoring device for deep-sea dual-gradient drilling according to claim 6, wherein, A lower limit plate (105) is fixed inside the upper anchor tip (103), and the lower limit plate (105) is used to prevent the counterweight heave compensation rod (2) from sliding out of the upper anchor tip (103).

8. The subsea heave compensation and anchoring device for deep - sea dual - gradient drilling according to claim 1, wherein, A jumper hose connection flange (408) is connected to the lowering flange (4).

9. The subsea heave compensation and anchoring device for deep - sea dual - gradient drilling according to claim 1, characterized in that, A counterweight frame (5) is fixed on the lowering flange (4).

10. The subsea heave compensation and anchoring device for deep - sea dual - gradient drilling according to claim 1, characterized in that, The lowering flange (4) is connected to an up-return pipe string (6).

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