Underwater flexible apparatus for sea well drilling

Abstract

The present invention relates to an underwater flexible unit used on an oceanic drilling riser. The flexible unit is mainly composed of a main structure and a flexible element assembly; wherein, the main structure is connected with the other parts of the riser and a lower annular blowout preventer; the flexible element assembly, which is positioned in the main structure and retained by the main structure, is composed of an upper spindle, a flexible element and a base; and the flexible element is connected with the upper spindle and the base and fixed in a body by a fixing flange, bolts and nuts. Adopting the rotational stiffness of the flexible element connection structure, the flexible unit is more effective than the spherical steel connection in terms of the control of the angle of the riser, and can be adapted to rotation in any direction, and the shock-absorbing and damping effects of the flexible unit are better than the shock-absorbing and damping effects of the spherical steel connection. The flexible unit can be flexibly designed in order to meet different oceanic drilling requirements. The flexible unit has the following advantages: the whole main structure has strong bearing capability, the structure is simple and compact, and maintenance and operation are convenient. Flexible units with different specifications can be designed according to different oceanic drilling requirements.

Description

technical field [0001] The invention belongs to the technical field of offshore oil drilling. Specifically, it is an underwater flexible device installed at the bottom of an ocean drilling riser for a deepwater floating ocean drilling platform (or ship). Its function is to allow for angular misalignment between the riser and BOP stack, thereby reducing bending moments on the riser. Background technique [0002] The drilling riser system is one of the important links in the whole offshore drilling equipment, and its products and technologies have been monopolized by developed countries such as Europe and the United States. At present, our country has been in a blank state in the design and manufacturing technology of the supporting equipment of the offshore drilling riser system, especially the underwater flexible device is monopolized by only three foreign companies in the world. [0003] Under the action of waves, the offshore drilling platform (or ship) not only swings b...

AI Technical Summary

Problems solved by technology

These movements will affect the stability of the riser system and the safety of the wellhead device. Because the riser system cannot adapt to and withstand the huge comprehensive external force, the drilling project will be interrupted, or even unable to resume drilling, resulting in drilling failure and causing serious damage to the offshore drilling project. Huge losses, even catastrophic consequences

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