Method for dismounting offshore platform pile foundation by twisting and pulling up

Abstract

The invention provides a method for dismounting an offshore platform pile foundation by twisting and pulling up and belongs to the technical field of offshore platform dismounting construction. By means of the method, the defects that the pile foundation underwater cutting operation is high in difficulty, high in risk and long in construction period are avoided, and the offshore platform pile foundation is fast and effectively dismounted on the water surface. According to the dismounting method, an offshore tug exerts torque on the top of a pile through a long horizontal beam and exerts the vertical up-pulling force by combining with a lifting machine on the tug, and then the whole pile foundation is completely pulled out. The method adopts the lever principle to remarkably reduce the exerted twisting force, and meanwhile the anti-pulling bearing capacity of the pile foundation is reduced through the exerted torque and up-pulling force. The method includes the following steps that A, the tug is connected with the top of the pile foundation through the horizontal rigid beam; B, the twisting moment is exerted on the pile top; and C, the vertical pulling force is exerted on the pile top. The dismounting method has the advantages that the whole pile foundation can be pulled out while the pulling force is small.

Description

technical field [0001] The invention relates to a technical method for dismantling an offshore platform, in particular to a technical method for dismantling a pile foundation of an offshore platform. Background technique [0002] At present, there are hundreds of jacket offshore platforms in my country's sea area, and these platforms have made important contributions to my country's offshore oil exploitation. With the expiration of the service period, the platform will be discontinued and discarded. In accordance with international practice and national laws and regulations, the abandoned platforms must be dismantled. International regulations favor the complete dismantling of the jacket, which requires that the pile foundations of abandoned offshore platforms should be cut 4m below the mud surface of the seabed. The removal of the jacket pile foundation is the longest and most expensive project in the entire offshore platform removal process. Regardless of the demolition...

AI Technical Summary

Problems solved by technology

The underwater cutting method is very limited, the operation is difficult and the risk is high, and it takes a long time to complete a cutting underwater, which can reach more than ten or twenty hours, which is prone to engineering problems

[0003] In order to quickly and effectively remove the pile foundation of the offshore platform and avoid the disadvantages of difficult operation, high risk and long construction period of the underwater cutting operation, this patent proposes a method for removing the pile foundation of the offshore platform by twisting and pulling up

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