Ocean oil and gas underwater wellhead protection device and installation method thereof

Abstract

The invention relates to an offshore oil and gas underwater wellhead protection device and an installation method thereof. The device comprises an outer protection structure fixed to a wellhead suction anchor, and an underwater wellhead penetrates through the outer protection structure; the supporting structure is used for supporting and distributing external loads and comprises a plurality of supporting frames arranged in the circumferential direction of the outer protection structure at intervals. And the stress rod piece structure is used for bearing the external load transmitted by the supporting structure and comprises a plurality of stress rods, and the two ends of each stress rod are detachably connected to the supporting frame and the side wall of the wellhead suction anchor correspondingly. The stability problem possibly encountered by an offshore oil and gas wellhead in a severe marine environment is solved, additional protection and support are added for a connecting area, the bending resistance of the connecting area is remarkably improved, and then the overall stability of the underwater wellhead is effectively enhanced. According to the invention, the offshore oil and gas wellhead can adapt to a more complex storm flow environment, and the risk of offshore operation is reduced.

Description

Technical Field

[0001] The present invention relates to the technical field of marine oil and gas engineering, and in particular to a marine oil and gas underwater wellhead protection device and an installation method thereof. Background Art

[0002] Offshore oil and gas development usually faces extreme environmental conditions, especially in deep and ultra-deep water areas, where natural factors such as wind, waves, and currents are particularly significant. Strong winds and waves and complex currents, especially during typhoon seasons and in areas with frequent internal waves and currents, pose huge challenges to the stability and safety of offshore oil and gas facilities. In areas with soft seabeds, deepwater oil and gas development generally adopts an underwater suction anchor wellhead mode to improve the bearing capacity of the underwater wellhead.

[0003] In order to facilitate the installation of large underwater equipment, the wellhead of the underwater suction anchor wellhead is generally about 3 to 4 meters above the seabed, and the underwater wellhead is connected to the blowout preventer system. During the drilling operation, the blowout preventer system is subjected to large lateral current forces due to its large size and weight, as well as its large frontal area. In addition, the floating drilling platform (or ship) drifts due to the action of wind and waves, and its force will also be transmitted to the underwater wellhead through the riser, further increasing the force and instability of the suction anchor wellhead system. The suction anchor is buried in the seabed stratum, is subject to the lateral constraints of the soil, and has a large bearing capacity, so it has good stability.

[0004] However, the area where the underwater wellhead and the BOP are connected is exposed to the marine environment, has a small structure size, weak bending resistance, and bears a large load. When subjected to external forces such as wind, waves, and currents for a long time, it may lead to instability or fatigue failure. Therefore, special attention must be paid to the strength and durability of this key connection area, and corresponding design measures must be taken to ensure the reliability and long-term stability of the overall structure.

[0005] In the process of offshore oil and gas extraction, the stability of the wellhead is directly related to the safety of the operation and the efficiency of extraction, so it is very important to ensure the stability of the wellhead. In marine engineering operations, the traditional practice is usually to increase the overall size of the underwater wellhead through theoretical calculations to improve its bending resistance and stability. However, increasing the size of the underwater wellhead will also increase the size of the surface conduit connected to the lower part. This not only greatly increases the cost, but also because the increase in the structural size is still limited, the improvement effect is also limited to a certain extent. Therefore, the practice of simply relying on increasing the size of the wellhead to improve stability has certain limitations.

[0006] Therefore, the inventor, relying on many years of experience and practice in related industries, proposes a marine oil and gas underwater wellhead protection device and an installation method thereof to overcome the defects of the prior art. Summary of the invention

[0007] The purpose of the present invention is to provide a marine oil and gas underwater wellhead protection device and its installation method, so as to overcome the stability problems that the marine oil and gas wellhead may encounter in the harsh marine environment. The present invention adds additional protection and support to the connection area, significantly improves its anti-bending ability, and thus effectively enhances the overall stability of the underwater wellhead. The present invention can make the marine oil and gas wellhead adapt to more complex wind, wave and current environments, and reduce the risks of offshore operations.

[0008] The object of the present invention is achieved by providing an underwater wellhead protection device for marine oil and gas, comprising:

[0009] An outer protective structure fixed to the wellhead suction anchor, through which the underwater wellhead passes;

[0010] A support structure for supporting and distributing external loads, comprising a plurality of support frames spaced apart along the circumference of the outer protective structure;

[0011] The stress-bearing rod structure is used to bear the external load transmitted by the supporting structure, and comprises a plurality of stress-bearing rods, and the two ends of each stress-bearing rod are detachably connected to the supporting frame and the side wall of the wellhead suction anchor.

[0012] In a preferred embodiment of the present invention, the marine oil and gas underwater wellhead protection device includes a fixing ring, which is arranged between the marine oil and gas underwater wellhead protection device and the blowout preventer system, and is used for axial positioning of the marine oil and gas underwater wellhead protection device along the underwater wellhead head.

[0013] In a preferred embodiment of the present invention, the marine oil and gas underwater wellhead protection device includes a guide structure, which includes a plurality of guide rods fixedly connected to the wellhead suction anchor and guide grooves arranged on each of the support frames, and each of the guide rods is respectively passed through the corresponding guide groove.

[0014] In a preferred embodiment of the present invention, the bottom end of each guide rod is embedded in a reserved circular hole on the top surface of the wellhead suction anchor.

[0015] In a preferred embodiment of the present invention, the support frame is a triangular support frame, a right-angled side wall of the triangular support frame is fixedly connected to the outer protective structure, and another right-angled side wall of the triangular support frame is arranged along the radial direction of the outer protective structure.

[0016] In a preferred embodiment of the present invention, the outer protective structure includes a cylindrical structure, the underwater wellhead mouth passes through the cylindrical structure, and the side wall of the underwater wellhead mouth is arranged in close contact with the side wall of the cylindrical structure.

[0017] In a preferred embodiment of the present invention, an inspection hole is provided on the side wall of the cylindrical structure, and the inspection hole is used to monitor the connection status between the underwater wellhead head and the marine oil and gas underwater wellhead protection device and / or constitute a valve reserved space.

[0018] In a preferred embodiment of the present invention, both ends of each of the force-bearing rods are respectively connected to the support frame and the side wall of the wellhead suction anchor by bolts.

[0019] The object of the present invention can also be achieved by a method for installing the aforementioned marine oil and gas underwater wellhead protection device, comprising:

[0020] Step S1, lowering the device: lowering the assembled marine oil and gas underwater wellhead protection device to a predetermined position of the underwater wellhead;

[0021] Step S2, device positioning: positioning the marine oil and gas underwater wellhead protection device on the wellhead suction anchor through the guide structure of the marine oil and gas underwater wellhead protection device;

[0022] Step S3, fixing device: the bottom end of each of the force-bearing rods of the marine oil and gas underwater wellhead protection device is detachably connected to the side wall of the wellhead suction anchor.

[0023] In a preferred embodiment of the present invention, an underwater robot is used to assist in the installation of the marine oil and gas underwater wellhead protection device.

[0024] As described above, the marine oil and gas underwater wellhead protection device and the installation method thereof of the present invention have the following beneficial effects:

[0025] The present invention aims to enhance the stability of the connection between the suction pile underwater wellhead and the blowout preventer system (or Christmas tree), so that it can withstand the complex load conditions in the marine environment and the impact of the harsh marine environment. The marine oil and gas underwater wellhead protection device of the present invention provides additional protection and support for the connection through the support structure and the force-bearing rod structure, thereby enhancing the stability of the underwater wellhead, and the removable connection of the force-bearing rod structure enables the device to be reused to reduce economic costs and environmental impacts. The guide rod of the present invention facilitates the convenient installation of the marine oil and gas underwater wellhead protection device through the guide groove on the support frame, while enhancing the structural stability of the marine oil and gas underwater wellhead protection device. The present invention is simple in design, easy to disassemble and can be recovered after the operation is completed.

[0026] Through the installation method of the present invention, the marine oil and gas underwater wellhead protection device can be efficiently and safely installed at the underwater wellhead, providing a strong guarantee for oil and gas production operations. This innovative installation method not only improves the operation efficiency, but also reduces the construction risk, bringing significant economic and environmental benefits to the exploration and development of marine oil and gas resources.

[0027] The present invention is suitable for short-term drilling operations and can also meet the needs of long-term production operations. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] The following drawings are only intended to illustrate and explain the present invention, and are not intended to limit the scope of the present invention.

[0029] in:

[0030] Figure 1 It is an isometric diagram of the marine oil and gas underwater wellhead protection device of the present invention.

[0031] Figure 2 It is a front view of the marine oil and gas underwater wellhead protection device of the present invention.

[0032] Figure 3 It is a schematic diagram of the use status of the marine oil and gas underwater wellhead protection device of the present invention.

[0033] In the figure:

[0034] 100. Marine oil and gas underwater wellhead protection device;

[0035] 1. External protective structure; 11. Inspection hole;

[0036] 2. Support structure; 21. Support frame;

[0037] 3. Load-bearing rod structure; 31. Load-bearing rod; 32. Bolt;

[0038] 4. Fixed ring;

[0039] 51. guide rod; 52. guide groove;

[0040] 6. Wellhead suction anchor;

[0041] 7. Underwater wellhead;

[0042] 8. BOP system;

[0043] 9. Soil. DETAILED DESCRIPTION

[0044] In order to have a clearer understanding of the technical features, purposes and effects of the present invention, specific embodiments of the present invention are now described with reference to the accompanying drawings.

[0045] The specific embodiments of the present invention described herein are only used to explain the purpose of the present invention and cannot be understood as limiting the present invention in any way. Under the guidance of the present invention, technicians can conceive of any possible variations based on the present invention, which should be considered to belong to the scope of the present invention. It should be noted that when an element is referred to as "arranged on" another element, it can be directly on the other element or there can also be a central element. When an element is considered to be "connected" to another element, it can be directly connected to the other element or there may be a central element at the same time. The terms "installed", "connected" and "connected" should be understood in a broad sense, for example, it can be a mechanical connection or an electrical connection, or it can be the internal communication of two elements, it can be directly connected, or it can be indirectly connected through an intermediate medium. For ordinary technicians in this field, the specific meanings of the above terms can be understood according to the specific circumstances. The terms "vertical", "horizontal", "up", "down", "left", "right" and similar expressions used herein are only for illustrative purposes and do not represent the only implementation method.

[0046] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as those generally understood by those skilled in the art to which this application belongs. The terms used herein in the specification of this application are only for the purpose of describing specific embodiments and are not intended to limit this application. The term "and / or" used herein includes any and all combinations of one or more related listed items.

[0047] like Figure 1 , Figure 2 , Figure 3 As shown, the present invention provides a marine oil and gas underwater wellhead protection device 100, which is arranged at the connection between the underwater suction anchor wellhead and the blowout preventer system 8 (or oil production tree), including:

[0048] The outer protective structure 1 is fixed on the wellhead suction anchor 6, and the underwater wellhead 7 is passed through the outer protective structure 1. The wellhead suction anchor 6 is buried in the soil 9 of the seabed formation, is laterally constrained by the soil 9, has a large bearing capacity, and has good stability.

[0049] The support structure 2 is used to support and distribute external loads, and includes a plurality of support frames 21 (which can be fixed to the outer protective structure 1 by welding) arranged at intervals along the circumference of the outer protective structure 1; the support structure 2 is a main component of the marine oil and gas underwater wellhead protection device, and its main function is to support and distribute external loads and provide structural stability and strength.

[0050] The stress-bearing rod structure 3 is used to bear the external load transmitted by the supporting structure 2, and includes a plurality of stress-bearing rods 31. The two ends of each stress-bearing rod 31 are detachably connected to the supporting frame 21 and the side wall of the wellhead suction anchor 6. Each stress-bearing rod 31 is a key component that bears the maximum load, mainly bearing the external load, and has a high strength; each stress-bearing rod 31 is detachably connected to the underwater wellhead (such as bolted connection), which is easy to operate and can be replaced at any time if fatigue damage occurs due to long-term cyclic load.

[0051] The present invention aims to enhance the stability of the connection between the suction pile underwater wellhead and the blowout preventer system, so that it can withstand the complex load conditions in the marine environment and the impact of the harsh marine environment (mainly typhoon weather and internal wave currents). The marine oil and gas underwater wellhead protection device of the present invention provides additional protection and support for the connection through the support structure 2 and the force-bearing rod structure 3, thereby enhancing the stability of the underwater wellhead, and the detachable connection of the force-bearing rod structure 3 enables the device to be reused to reduce economic costs and environmental impacts. The present invention is simple in design, easy to disassemble and can be recycled after the operation is completed. The present invention is suitable for both short-term drilling operations and long-term production operations.

[0052] Further, if Figure 1 , Figure 2 As shown, in order to prevent the protection device from moving up and down, the marine oil and gas underwater wellhead protection device 100 includes a fixing ring 4, which is arranged between the marine oil and gas underwater wellhead protection device 100 and the blowout preventer system 8, and is used for positioning the marine oil and gas underwater wellhead protection device along the axial direction of the underwater wellhead 7. The height of the fixing ring 4 is related to the position of the blowout preventer system 8 after installation.

[0053] Further, if Figure 1 , Figure 2 As shown, to ensure accurate positioning and stable fixation of the device, the marine oil and gas underwater wellhead protection device 100 also includes a guide structure, which includes a plurality of guide rods 51 fixedly connected to the wellhead suction anchor 6 and guide grooves 52 provided on each support frame 21, and each guide rod 51 is respectively passed through the corresponding guide groove 52. The guide rod 51 passes through the guide groove 52 on the support frame 21, which facilitates the convenient installation of the marine oil and gas underwater wellhead protection device and enhances the structural stability of the marine oil and gas underwater wellhead protection device.

[0054] Furthermore, the bottom end of each guide rod 51 is embedded in a reserved circular hole on the top surface of the wellhead suction anchor 6 .

[0055] Further, if Figure 1 , Figure 2As shown, the support frame 21 is a triangular support frame, a right-angled side wall of the triangular support frame is fixedly connected (such as welded) to the outer protective structure 1, and another right-angled side wall of the triangular support frame is arranged along the radial direction of the outer protective structure 1. In a specific embodiment, the number of support frames 21 is 4, which are evenly distributed around the outer protective structure 1 (cylindrical structure).

[0056] Further, if Figure 1 , Figure 2 As shown, the outer protective structure 1 includes a cylindrical structure, which is located on the step of the underwater wellhead. The underwater wellhead mouth 7 passes through the cylindrical structure, and the side wall of the underwater wellhead mouth 7 is fitted with the side wall of the cylindrical structure. The assembly gap between the two is controlled within 0.3 mm. The corresponding cylindrical structure size is designed according to the size of the underwater wellhead mouth 7.

[0057] Further, if Figure 1 , Figure 2 As shown, an inspection hole 11 is arranged on the side wall of the cylindrical structure, and the inspection hole is used to monitor the connection status between the underwater wellhead head 7 and the marine oil and gas underwater wellhead protection device 100, and to provide a reserved space for the valve on the side wall of the underwater wellhead, i.e., to constitute a valve reserved space; at the same time, opening a hole in the cylindrical structure can reduce the overall weight of the device.

[0058] Further, if Figure 2 As shown, two ends of each force-bearing rod 31 are connected to the support frame 21 and the side wall of the wellhead suction anchor 6 through bolts 32 respectively.

[0059] The present invention also provides a method for installing a marine oil and gas underwater wellhead protection device 100, comprising:

[0060] Step S1, lowering the device: lowering the assembled marine oil and gas underwater wellhead protection device 100 to a predetermined position of the underwater wellhead;

[0061] Specifically, the marine oil and gas underwater wellhead protection device 100 is slowly lowered to a predetermined position of the underwater wellhead using a drill pipe or a wire rope. In this process, an underwater robot (ROV) can be used for auxiliary operation to ensure that the device can be accurately placed at the target position.

[0062] Step S2, device positioning: positioning the marine oil and gas underwater wellhead protection device on the wellhead suction anchor through the guide structure of the marine oil and gas underwater wellhead protection device 100;

[0063] Specifically, the lower part of the marine oil and gas underwater wellhead protection device 100 realizes precise positioning of the device through the cooperation of the guide rod 51 and the guide groove 52. This design ensures that the device can be stably fixed on the wellhead, providing a reliable basis for subsequent connection and fixation.

[0064] Step S3, fixing device: the bottom end of each force-bearing rod 31 of the marine oil and gas underwater wellhead protection device 100 is detachably connected to the side wall of the wellhead suction anchor 6, the state is as follows Figure 3 shown.

[0065] Specifically, the stress rod 31 of the device is tightly combined with the wellhead suction anchor 6 by bolts to fix the device. This step is crucial because it ensures that the device can withstand the load from the upper structure, thereby improving the stability of the entire wellhead structure. The stress rod 31 can be replaced with the assistance of an underwater robot (ROV) to achieve the reuse of the device.

[0066] During the entire implementation process, the present invention adopts advanced underwater robot (ROV) auxiliary technology to make the lowering, positioning and fixing process of the device more accurate and efficient.

[0067] Through the above steps, the marine oil and gas underwater wellhead protection device 100 of the present invention can be efficiently and safely installed at the underwater wellhead, providing a strong guarantee for oil and gas production operations. This innovative installation method not only improves the operating efficiency, but also reduces the construction risk, bringing significant economic and environmental benefits to the exploration and development of marine oil and gas resources.

[0068] As described above, the marine oil and gas underwater wellhead protection device and the installation method thereof of the present invention have the following beneficial effects:

[0069] The present invention aims to enhance the stability of the connection between the suction pile underwater wellhead and the blowout preventer system, so that it can withstand the complex load conditions in the marine environment and the impact of the harsh marine environment. The marine oil and gas underwater wellhead protection device of the present invention provides additional protection and support for the connection through the support structure and the force-bearing rod structure, thereby enhancing the stability of the underwater wellhead, and the removable connection of the force-bearing rod structure enables the device to be reused to reduce economic costs and environmental impacts. The guide rod of the present invention facilitates the convenient installation of the marine oil and gas underwater wellhead protection device through the guide groove on the support frame, while enhancing the structural stability of the marine oil and gas underwater wellhead protection device. The present invention is simple in design, easy to disassemble and can be recovered after the operation is completed.

[0070] Through the installation method of the present invention, the marine oil and gas underwater wellhead protection device can be efficiently and safely installed at the underwater wellhead, providing a strong guarantee for oil and gas production operations. This innovative installation method not only improves the operation efficiency, but also reduces the construction risk, bringing significant economic and environmental benefits to the exploration and development of marine oil and gas resources.

[0071] The present invention is suitable for short-term drilling operations and can also meet the needs of long-term production operations.

[0072] The above description is only an illustrative embodiment of the present invention and is not intended to limit the scope of the present invention. Any equivalent changes and modifications made by any person skilled in the art without departing from the concept and principle of the present invention shall fall within the scope of protection of the present invention.

Claims

1. A marine oil and gas underwater wellhead protection device, characterized in that: include: An outer protective structure fixed to the wellhead suction anchor, through which the underwater wellhead passes; A support structure for supporting and distributing external loads, comprising a plurality of support frames spaced apart along the circumference of the outer protective structure; The stress-bearing rod structure is used to bear the external load transmitted by the supporting structure, and comprises a plurality of stress-bearing rods, and the two ends of each stress-bearing rod are detachably connected to the supporting frame and the side wall of the wellhead suction anchor.

2. The marine oil and gas underwater wellhead protection device according to claim 1, characterized in that: The marine oil and gas underwater wellhead protection device comprises a fixing ring, which is arranged between the marine oil and gas underwater wellhead protection device and the blowout preventer system and is used for positioning the marine oil and gas underwater wellhead protection device along the axial direction of the underwater wellhead head.

3. The marine oil and gas underwater wellhead protection device according to claim 2, characterized in that: The marine oil and gas underwater wellhead protection device includes a guide structure, which includes a plurality of guide rods fixedly connected to the wellhead suction anchor and guide grooves arranged on each of the support frames, and each of the guide rods is respectively inserted through the corresponding guide groove.

4. The marine oil and gas underwater wellhead protection device according to claim 3, characterized in that: The bottom end of each guide rod is embedded in a reserved circular hole on the top surface of the wellhead suction anchor.

5. The marine oil and gas underwater wellhead protection device according to claim 1, characterized in that: The support frame is a triangular support frame, a right-angled side wall of the triangular support frame is fixedly connected to the outer protective structure, and another right-angled side wall of the triangular support frame is arranged along the radial direction of the outer protective structure.

6. The marine oil and gas underwater wellhead protection device according to claim 1, characterized in that: The outer protection structure comprises a cylindrical structure, the underwater wellhead mouth passes through the cylindrical structure, and the side wall of the underwater wellhead mouth is arranged in close contact with the side wall of the cylindrical structure.

7. The marine oil and gas underwater wellhead protection device according to claim 6, characterized in that: An inspection hole is arranged on the side wall of the cylindrical structure, and the inspection hole is used to monitor the connection status between the underwater wellhead head and the marine oil and gas underwater wellhead protection device and / or to form a valve reserved space.

8. The marine oil and gas underwater wellhead protection device according to claim 4, characterized in that: Both ends of each of the force-bearing rods are respectively connected to the support frame and the side wall of the wellhead suction anchor by bolts.

9. A method for installing a marine oil and gas underwater wellhead protection device according to any one of claims 1 to 8, characterized in that: include: Step S1, lowering the device: lowering the assembled marine oil and gas underwater wellhead protection device to a predetermined position of the underwater wellhead; Step S2, device positioning: positioning the marine oil and gas underwater wellhead protection device on the wellhead suction anchor through the guide structure of the marine oil and gas underwater wellhead protection device; Step S3, fixing device: the bottom end of each of the force-bearing rods of the marine oil and gas underwater wellhead protection device is detachably connected to the side wall of the wellhead suction anchor.

10. The method for installing the marine oil and gas underwater wellhead protection device according to claim 9, characterized in that: During the installation of the marine oil and gas underwater wellhead protection device, an underwater robot is used to perform auxiliary operations.

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