Method of dealing with deep-water internal wave flow for deep-water semi-submersible platform

Abstract

The invention discloses a method of dealing with deep-water internal wave flow for a deep-water semi-submersible platform. The method includes the following steps of 1, forecasting information, wherein conducting monitoring and early warning on the deep-wave internal wave flow, and predicting the information of the deep-water internal wave flow in advance; 2, changing platform orientation, whereinwhen the deep-water internal wave flow is monitored, the platform orientation is changed to a direction facing the deep-water internal water flow; 3, anchoring and reinforcing; 4, dragging wheels andpreventing deviation, wherein when the deep-water internal wave flow reaches the platform, the power and tension of a main tub are gradually increased, and the deviation amount of the platform is reduced; 5, removing the tug, wherein after the deep-water internal water flow disappears, the tug is removed, and a next operation is conducted. The method for conducting prediction in advance, changingthe orientation, conducting dragging on the wheels and preventing deviation is adopted to deal with the deep-water internal flow wave encountered in deep-water drilling, reduce the impact of the deep-water internal wave flow on the deep-water semi-submersible platform and ensure the operation, control and safe operation of the platform and is conducive to improvement of drilling time efficiency.The method is simple and convenient to operate and can be widely applied in the field of deep-water oil drilling.

Description

technical field [0001] The invention belongs to the technical field of oil and gas resource drilling engineering, and in particular relates to a method for a deep-water semi-submersible platform to deal with deep-water internal waves. Background technique [0002] The deep-water internal wave current is a high-energy oceanic internal wave that occurs in a density-stabilized ocean with a structure such as image 3 As shown, it is divided into high-frequency internal waves, isolated internal waves and internal inertial waves. It has the characteristics of large amplitude, short period and randomness, and can generate strong wave-induced shear flow. The destructive force of the internal wave is mainly the upper and lower levels of the cline where the internal wave is generated, and two internal wave flows with opposite directions will be formed. This internal wave flow can be as high as 1.5m / s, like scissors, with great destructive power. [0003] A deep-water semi-submersibl...

AI Technical Summary

Problems solved by technology

It may cause damage to the riser or other underwater and above-water equipment; it may cause the underwater floating body to move up and down with the equal density surface or to float up and down quickly, making it difficult to operate; it may cause the towing cable to break during offshore towing operations; it may cause the offshore drilling device to break. cable and / or drift; it may cause the anchoring of the anchor positioning drilling unit;

If it is not handled properly, the huge sudden impact load generated by the internal wave will not only cause serious safety hazards to the floating body of the platform, but may also cause a sudden and large drift movement of the floating body of the platform, causing the mooring of the platform and the tension of the riser to be affected. Sharp increase, catastrophic accidents of mooring or riser breaking

[0004] Since the internal wave flow will affect the deepwater semi-submersible platform, it will directly threaten the maneuvering and safe operation of the platform

However, at present, there is no systematic method in China to deal with internal waves and currents in deep water in the South China Sea, so it is necessary to formulate an emergency response plan for internal waves and currents in the South China Sea

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