A movable double rubber core underwater annular blowout preventer

Abstract

The invention relates to the technical field of marine drilling equipment, and discloses a movable double rubber core underwater annular blowout preventer, which includes a shell, a connecting flange and a drilling tool. There are two connecting flanges, and They are respectively fixedly installed on the top and the bottom of the housing, and the drilling tool passes through the middle of the housing. Through the setting of the movable blowout preventer and the fixed blowout preventer, the wellbore is double-sealed, the well sealing effect is strengthened, the possibility of blowout is reduced, and the safety of drilling and workover construction is increased. At the same time, through the sliding sleeve, The arrangement of the piston barrel and the oil plug 2 enables the movable blowout preventer to move up and down in the casing, and enables the rubber core in the fixed blowout preventer to be opened and the movable preventer to be closed when there is a drilling tool in the well for tripping out and drilling. Spray the rubber core in the device, and make the movable blowout preventer move up and down with the drilling tool, reduce the movement between the rubber core and the drilling tool, and reduce the friction between the two.

Description

technical field [0001] The invention relates to the technical field of marine drilling equipment, in particular to a movable double rubber core underwater annular blowout preventer. Background technique [0002] Annular blowout preventer, also known as universal blowout preventer, is an important part of the well control device. It is mainly used to control wellhead pressure and prevent blowout accidents in drilling, workover, oil testing and other operations. Its working principle is as attached Figure 6 As shown: the hydraulic oil is injected from the oil plug 1, so that the piston block 3 rises to squeeze the rubber core 2, so that the rubber core 2 gathers in the middle to form a closed space, thereby forming a seal on the wellhead. At the same time, the ring blowout preventer The main functions of the device are: 1. When there are drilling tools in the well, it can seal the annular space of different sizes; 2. When there is no drilling tool in the well, it can fully sea...

AI Technical Summary

Problems solved by technology

[0003] When there is a drilling tool in the well, the drilling tool is in a certain bending state, so that the eccentricity is relatively large when it contacts the rubber core 2, so that the rubber core 2 cannot seal the space where the drilling tool is located, resulting in sealing failure. At the same time, when the rubber core 2 is in In the state of well sealing, when the drilling tool is forcibly pulled up and down the drill many times, the different cylindrical sections of the rubber core 2 are subjected to alternating shear stresses, and the closer to the inner wall, the greater the shear stress, because the fatigue shear strength of the rubber is only its static 20% to 30% of the shear strength, so repeated forced tripping can easily lead to fatigue shear failure of the rubber near the inner wall, and large pieces of degumming on the inner wall of the rubber core 2 will occur, causing damage to the rubber core 2 and causing a blowout

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