Blow-out prevention valve in double-layer pipe

Abstract

The invention provides a blow-out prevention valve in a double-layer pipe. The device comprises a piston, a rubber core, a valve seat, a differential pressure sliding sleeve, a supporting plate, an inner pipe, an outer pipe, an upper joint of the inner pipe and a lower joint of the inner pipe. The differential pressure sliding sleeve is located in an inner pipe cavity and is positioned by an innerpipe step and the lower joint of the inner pipe; the piston and the rubber core are located on the outer wall of the inner pipe and are positioned by the inner pipe step and the valve seat, and a cavity formed by the piston, the valve seat and the outer wall of the inner pipe communicates with a cavity formed by the differential pressure sliding sleeve and the inner pipe; and the supporting plateis fixed to the inner pipe step through the upper joint of the inner pipe and the lower joint of the inner pipe, and the inner pipe is positioned by an outer pipe step. According to the blow-out prevention valve in the double-layer pipe, self-closing can be realized in case of overflow during double-layer pipe drilling or mining, the occurrence of well kick or blowout accidents is effectively prevented, and power fluid can be used for reopening after the environment in the well is stable to continue drilling or mining, time is saved, the drilling and milling efficiency is improved.

Description

technical field [0001] The invention relates to the technical field of double-tube drilling and mining blowout prevention, in particular to a double-tube drilling and mining blowout preventer. Background technique [0002] The double-layer pipe drilling and production method is to use double-layer pipe and its supporting equipment for drilling and production. It is currently applicable to double-gradient drilling and hydrate solid-state fluidization mining. It is one of the frontier topics in the current energy field and is mainly used in deep sea. Development of oil and gas and shallow hydrates. The difference from conventional drilling is that the double-layer pipe forms two channels through the inner pipe and the annulus of the inner and outer pipes. The annulus of the inner and outer pipes is the drilling fluid injection channel, and the inner pipe is the drilling fluid return channel, thus forming an independent loop circulation channel. [0003] The drilling and minin...

AI Technical Summary

Problems solved by technology

[0003] The drilling and mining process of double-layer pipe puts forward new requirements for related equipment. The existing blowout preventer can seal the drill pipe and the annulus of the well wall or cut the drill pipe to fully seal the wellhead. After using double-layer pipe, The return liquid is returned from the inside of the pipe without going through the drill pipe and the annulus of the borehole wall, so it is impossible to effectively control the annulus of the inner and outer pipes of the double-layer pipe and the two channels of the inner pipe

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