A method for connecting steel cables of a deep-sea self-floating unpowered drilling platform

Abstract

The present invention provides a method for connecting steel cables of a deep-sea self-floating non-powered drilling platform. The present invention achieves safe and efficient connection of steel cables of a deep-sea self-floating non-powered drilling platform by designing the platform steel cables in sections, using an anchoring boat to connect and lower two sections of the platform steel cables, and using mechanical equipment such as an anchoring boat winch and a platform winch to ensure safety during the platform steel cable connection process. The advantages of the present invention are as follows: 1. The anchor end cable, gravity anchor, and buoy are connected by a wire rope and a Havers clamp, which is highly safe; 2. The platform end cable and the anchor end cable can be connected and lowered in advance using an anchoring boat, which improves construction efficiency; 3. During the stage of connecting the platform steel cable and the conversion joint, four protection measures, including a platform winch, a limit plate, a Havers clamp, and a crawler crane, are set on site, which provides high reliability.

Description

Technical Field

[0001] The present invention relates to the technical field of cable transfer construction for offshore drilling platforms, and in particular to a method for connecting steel cables for deep-sea self-floating unpowered drilling platforms. Background Art

[0002] Currently, bridge construction becomes increasingly difficult as water depth increases. When building bridges in deep water (deep sea), large-diameter bored piles are generally required as the bridge foundation. The construction process is easily affected by factors such as tidal currents and wind and waves, so a temporary drilling construction platform is required to eliminate construction interference and solve the problem of precise positioning. When constructing pile foundations in deep water (deep sea) areas, using a conventional fixed platform as the drilling construction platform results in a long construction period and a significant impact on the environment. Self-floating platforms, on the other hand, can be manufactured as a whole to shorten the construction period and are less affected by water level fluctuations and water depth, but are more affected by wind and wave forces and current forces.

[0003] The site of the No. 5 main tower pier of the Xihoumen Highway-Rail Bridge on the Ningbo-Zhoushan Railway is located in deep water, with rapid currents and a complex underwater environment. Therefore, a "self-floating drilling platform" was used for bored pile construction. This platform was prefabricated as a single piece at a shipyard and then floated to the bridge site for initial positioning using gravity anchors and steel cables. A cable reel system on the platform's top was then used to precisely position the platform. Finally, anchors were constructed and the entire structure was lifted out of the water, stabilizing it. This significantly reduced the impact of wind, wave, and current forces, thereby improving construction efficiency. However, this self-floating drilling platform presented challenges, such as the difficulty and high risk of initial positioning using gravity anchors and steel cables. Summary of the Invention

[0004] The object of the present invention is to provide a method for connecting steel cables of a deep-sea self-floating unpowered drilling platform with easy initial positioning and low risk.

[0005] The object of the present invention is achieved like this:

[0006] A method for connecting steel cables of a deep-sea self-floating unpowered drilling platform is characterized by the following specific construction steps:

[0007] A. Analyze and design the location of the gravity anchor based on the drilling platform structure, the hydrological conditions of the bridge site, the underwater topography, and other conditions, and lay the gravity anchor in advance;

[0008] B. Design the platform cable based on the actual situation on site. The platform cable is divided into two sections: the platform end cable and the anchor end cable. The adjacent ends of the platform end cable and the anchor end cable are equipped with one open cable segment and one closed cable segment respectively.

[0009] C. One end of the anchor cable is first connected to the gravity anchor via an open cable joint. The other end of the anchor cable is then floated on the water using a buoy. The anchor cable is connected to the buoy and the closed cable joint at the other end using a first auxiliary wire rope. The anchor cable is then reconnected to the buoy at the middle of the anchor cable using a second auxiliary wire rope via a Havers clamp and placed in the water.

[0010] D. The end of the platform-end cable with an open cable joint is placed on the anchoring boat in advance. The anchoring boat carries the end of the platform-end cable with an open cable joint to the buoy. First, the first auxiliary wire rope is disconnected from the side of the buoy. The first auxiliary wire rope is connected to one of the anchoring boat winches on the anchoring boat. Then, the anchoring boat winch is started. The closed cable joint at the other end of the anchor-end cable and the Havers clamp in the middle are reeled into the deck of the anchoring boat through the first auxiliary wire rope and the second auxiliary wire rope. After that, the first auxiliary wire rope, the second auxiliary wire rope and the Havers clamp are removed. The closed cable joint at the other end of the anchor-end cable is connected to the open cable joint at one end of the platform-end cable. The buoy is temporarily fixed to the side of the anchoring boat with the wire rope.

[0011] E. After the connection is completed, start the other anchoring boat winch to slowly release the rope. The cable at the platform end, driven by its own weight, drives the drum to rotate clockwise and slowly sink into the sea. The rope release speed of the anchoring boat winch is controlled on site to control the rope release speed of the drum. This measure can prevent the rope from losing control during the lowering process and ensure construction safety. While the anchoring boat winch controls the drum to release the rope, the anchoring boat gradually moves towards the platform, repeating the rope release action until the anchoring boat is close to the platform.

[0012] F. Lower the wire rope of the platform winch through the steering seat to the anchoring boat, connect the wire rope of the platform winch to the closed cable joint of the platform end cable, and use the crawler crane to lift the Haver clamp behind the closed cable joint of the platform end cable;

[0013] G. Then start the platform winch to pull the platform end cable to the steering seat on the top surface of the platform. Then use the crawler crane to lift the closed cable segment of the platform end cable through the steering seat. Next, start the platform winch again and slowly pull the closed cable segment of the platform end cable through the hole in the reaction seat.

[0014] H. After the closed cable segment of the platform end cable passes through the reaction seat, use the limit card to temporarily fix the closed cable segment on the reaction seat. After removing the wire rope from the platform winch, reconnect the wire rope of the platform winch to the Haver clamp. After the connection is completed, start the platform winch again and pull the closed cable segment until it reaches the conversion joint on the top surface of the platform. Use the crawler crane to assist in connecting the closed cable segment and the conversion joint.

[0015] I. The closed cable segment of the platform cable is connected to the conversion joint, and the platform cable transfer is completed. Repeat the above steps to complete the connection of all platform cables. Finally, the platform is accurately positioned through the cable reeling system on the top of the floating platform.

[0016] Advantages of the present invention:

[0017] 1. The anchor end cable, gravity anchor and buoy are connected by wire rope and Haversian clamp, which is highly safe.

[0018] 2. The platform end cable and the anchor end cable can be connected and lowered in advance using an anchoring boat, which improves construction efficiency;

[0019] 3. During the connection stage between the platform steel cable and the conversion joint, four protection measures including platform winch, limit plate, Haver clamp and crawler crane are set on site to ensure high reliability. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 is a diagram of the arrangement of the anchor end cable of the present invention;

[0021] Figure 2 is a layout diagram of the anchor boat line-releasing device of the present invention;

[0022] Figure 3 This is a schematic diagram of on-site construction during the connection phase between the steel cable, the platform winch, and the crawler crane of the present invention;

[0023] Figure 4 It is a schematic diagram of on-site construction during the connection stage of the steel cable and the platform top conversion joint of the present invention. DETAILED DESCRIPTION

[0024] The specific embodiments of the present invention are further described below with reference to specific examples and accompanying drawings.

[0025] Figure 1 This is the layout of the anchor cable. One end of anchor cable 8 is first connected to the gravity anchor 7 via an open cable segment 6. The other end of anchor cable 8 is then connected to buoy 1, allowing the other end of anchor cable 8 to float on the water. Anchor cable 8 is connected to buoy 1 and the closed cable segment 3 at the other end of anchor cable 8 using a first auxiliary steel wire 2. A second auxiliary steel wire 4 is used to connect the middle of anchor cable 8 to buoy 1 via a Havers clamp 5, and then placed in the water.

[0026] Figure 2 This is a layout diagram of the anchor-casting boat line-releasing device, in which the cable-releasing drum 9 is used to place the cable drum to facilitate the rotation of the cable drum, the drum 10 is used to accommodate the cable and lower the cable by rotation, and the anchor-casting boat winch 11 is used to provide power to the drum 10 to rotate it.

[0027] A method for connecting steel cables of a deep-sea self-floating unpowered drilling platform, the specific construction steps are as follows:

[0028] A. Analyze and design the location of the gravity anchor based on the drilling platform structure, the hydrological conditions of the bridge site, the underwater topography, and other conditions, and lay the gravity anchor 7 in advance;

[0029] B. Design the platform cable based on the actual site conditions. The platform cable is divided into two sections: the platform end cable 12 and the anchor end cable 8. The adjacent ends of the platform end cable 12 and the anchor end cable 8 are equipped with an open cable socket and a closed cable socket respectively.

[0030] C. One end of the anchor cable 8 is first connected to the gravity anchor 7 via an open cable joint 6. The other end of the anchor cable 8 is then floated on the water surface using a buoy 1. The anchor cable 8 is connected to the buoy 1 and the closed cable joint 3 at the other end of the anchor cable 8 using a first auxiliary steel wire rope 2. The anchor cable 8 is then reconnected to the buoy 1 at its middle portion using a second auxiliary steel wire rope 4 via a Havers clamp 5 and placed in the water.

[0031] D. One end of the platform end cable 13 with the open cable joint is placed on the anchoring boat in advance. The anchoring boat carries the one end of the platform end cable 13 with the open cable joint to the buoy 1. First, the first auxiliary steel wire rope 2 on the side of the buoy 1 is disconnected. The first auxiliary steel wire rope 2 is connected to one of the anchoring boat winches 12 on the anchoring boat. Then, the anchoring boat winch 12 is started to reel in the closed cable joint 3 at the other end of the anchor end cable 8 and the Havers clamp 5 in the middle through the first auxiliary steel wire rope 2 and the second auxiliary steel wire rope 4 to the deck of the anchoring boat. Later, the first auxiliary steel wire rope 2, the second auxiliary steel wire rope 4 and the Havers clamp 5 are removed, and the closed cable joint 3 at the other end of the anchor end cable 8 is connected to the open cable joint at one end of the platform end cable 12. The buoy 1 is temporarily fixed to the side of the anchoring boat with the steel wire rope.

[0032] E. After the connection is completed, start the other anchoring boat winch 11 to slowly release the rope. The cable 13 at the platform end drives the drum 10 to rotate clockwise and slowly sink into the sea under its own weight. The rope release speed of the anchoring boat winch 11 is controlled on site to control the rope release speed of the drum 10. This measure can prevent the rope from getting out of control during the lowering process and ensure construction safety. While the anchoring boat winch 11 controls the drum 10 to release the rope, the anchoring boat gradually moves towards the platform. The rope release action is repeated until the anchoring boat moves close to the platform.

[0033] F. Lower the wire rope of the platform winch 18 to the anchoring boat through the steering seat 16, connect the wire rope of the platform winch 18 to the closed cable joint 14 of the platform end cable 13, and use the crawler crane 17 to lift the Haversian clamp 15 behind the closed cable joint 14 of the platform end cable 13;

[0034] G. Then, start the platform winch 18 to pull the platform end cable 13 to the steering seat 16 on the platform top surface. Then, use the crawler crane 17 to lift the closed cable segment 14 of the platform end cable 13 through the steering seat 16. Next, start the platform winch 18 again and slowly pull the closed cable segment 14 of the platform end cable 13 through the hole of the reaction seat 20.

[0035] H. After the closed cable segment 14 of the platform-end cable 13 passes through the reaction seat 20, the closed cable segment 14 is temporarily fixed to the reaction seat 20 using the limit card 19. After the wire rope on the platform winch 18 is removed, the wire rope of the platform winch 18 is reconnected to the Haver clamp 15. After the connection is completed, the platform winch 18 is started again to pull the closed cable segment 14 until it reaches the conversion joint 21 on the top surface of the platform. The crawler crane 17 is used to assist in connecting the closed cable segment 14 to the conversion joint 21.

[0036] 1. The closed cable segment 14 of the platform end cable 13 is connected to the conversion joint 21, and the platform cable transfer is completed. Repeat the above steps to complete the connection operation of all platform cables, and finally realize the precise positioning of the platform through the cable reeling system on the top of the floating platform.

[0037] The construction method described in the present invention is based on the use of steel cable transfer construction for deep-sea self-floating drilling platforms. Obviously, this construction method can also be applied to the floating steel cable transfer construction of other structures. Therefore, all floating steel cable transfer construction of other structures based on the concept of this construction method is also considered to be within the scope of protection of the present invention.

Claims

1. A method for connecting steel cables of a deep-sea self-floating unpowered drilling platform, characterized in that: The specific construction steps are as follows: A. Analyze and design the location of the gravity anchor based on the drilling platform structure, the hydrological conditions of the bridge site, and the underwater topography, and lay the gravity anchor in advance; B. Design the platform cable based on the actual situation on site. The platform cable is divided into two sections: the platform end cable and the anchor end cable. The adjacent ends of the platform end cable and the anchor end cable are equipped with one open cable segment and one closed cable segment respectively. C. One end of the anchor cable is first connected to the gravity anchor via an open cable joint. The other end of the anchor cable is then floated on the water using a buoy. The anchor cable is connected to the buoy and the closed cable joint at the other end using a first auxiliary wire rope. The anchor cable is then reconnected to the buoy at the middle of the anchor cable using a second auxiliary wire rope via a Havers clamp and placed in the water. D. The end of the platform-end cable with an open cable joint is placed on the anchoring boat in advance. The anchoring boat carries the end of the platform-end cable with an open cable joint to the buoy. First, the first auxiliary wire rope is disconnected from the side of the buoy. The first auxiliary wire rope is connected to one of the anchoring boat winches on the anchoring boat. Then, the anchoring boat winch is started. The closed cable joint at the other end of the anchor-end cable and the Havers clamp in the middle are reeled into the deck of the anchoring boat through the first auxiliary wire rope and the second auxiliary wire rope. After that, the first auxiliary wire rope, the second auxiliary wire rope and the Havers clamp are removed. The closed cable joint at the other end of the anchor-end cable is connected to the open cable joint at one end of the platform-end cable. The buoy is temporarily fixed to the side of the anchoring boat with the wire rope. E. After the connection is completed, start the other anchoring boat winch to slowly release the rope. The cable at the platform end, driven by its own weight, drives the drum to rotate clockwise and slowly sink into the sea. The rope release speed of the anchoring boat winch is controlled on site to control the rope release speed of the drum. This measure can prevent the rope from losing control during the lowering process and ensure construction safety. While the anchoring boat winch controls the drum to release the rope, the anchoring boat gradually moves towards the platform, repeating the rope release action until the anchoring boat is close to the platform. F. Lower the wire rope of the platform winch through the steering seat to the anchoring boat, connect the wire rope of the platform winch to the closed cable joint of the platform end cable, and use the crawler crane to lift the Haver clamp behind the closed cable joint of the platform end cable; G. Then start the platform winch to pull the platform end cable to the steering seat on the top surface of the platform, and then use the crawler crane to lift the closed cable joint of the platform end cable over the steering seat; Next, start the platform winch again and slowly pull the closed cable segment of the platform end cable through the hole in the reaction seat; H. After the closed cable socket of the platform end cable passes through the reaction seat, use the limit card to temporarily fix the closed cable socket on the reaction seat. After removing the wire rope from the platform winch, reconnect the wire rope of the platform winch to the Haver clamp; After the connection is completed, start the platform winch again, pull the closed cable segment until it reaches the conversion joint on the top surface of the platform, and use the crawler crane to assist in connecting the closed cable segment and the conversion joint; I. The closed cable segment of the platform cable is connected to the conversion joint, and the platform cable transfer is completed. Repeat the above steps to complete the connection of all platform cables. Finally, the platform is accurately positioned through the cable reeling system on the top of the floating platform.

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