Device and method for preventing longitudinal vibration of marine riser in release mode

Abstract

The invention relates to a device for preventing a marine riser from longitudinally vibrating under a release mode. The device comprises a drilling platform, a riser, a working pipe and a blowout preventer, wherein the blowout preventer comprises a base, hydraulic cylinders and a holding sheet; a holding part is arranged at the lower end of the riser; the base sleeves the lower side of the holding part; at least three hydraulic cylinders with uniform intervals are arranged on the same circumference of the base; the holding sheet is connected to the output end of each hydraulic cylinder; and the working surface of the holding sheet is an arc surface which is consistent with the holding part in radian. The device has the advantages that the riser needs to be separated from the blowout preventer and the working pipe in an emergency circumstance; the hydraulic force is gradually reduced; when the clinical state is reached, the riser begins to slide relative to the blowout preventer and the hydraulic force is further reduced until the riser is separated from the blowout preventer and the working pipe; and the riser can be effectively prevented from longitudinally vibrating under the action of other external force, so that the risk of damage to the drilling platform and the riser can be alleviated.

Description

technical field [0001] The invention relates to the technical field of offshore oil exploitation, in particular to a device and a use method for preventing longitudinal vibration of an offshore riser in a release mode. Background technique [0002] Deep-water oil and gas exploitation inevitably suffers from the complex and changeable ocean wave-flow hydrodynamic environment. The marine riser exposed in deep water has a large slenderness ratio. As a key channel connecting the wellhead and the upper offshore platform, its service reliability is crucial The safe operation of offshore oil and gas drilling is of great significance. [0003] Due to the harsh environment of offshore oil exploitation, storms are usually encountered, which increases the speed of ocean currents and may cause tsunamis in severe cases. Moreover, most of the seabed is also an earthquake-prone area. The drilling platform in the process of exploitation is often Emergency transfer due to the impact, so tha...

AI Technical Summary

Problems solved by technology

However, the bottom of the drilling platform in the mining process is connected to the riser, and the riser is fixedly connected to the blowout preventer on the seabed. When there is an emergency transfer, the blowout preventer and the riser will be separated quickly, which will easily cause longitudinal vibration and cause serious damage to the drilling platform. Big impact

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