Well drilling wellhead anti-overflow control system

Abstract

The invention relates to a well drilling wellhead anti-overflow control system which comprises a semi-sealing large valve element flashboard and a semi-sealing small valve element flashboard on a wellhead main four way, a full-sealing singe flashboard and an annular bop; the top of the annular bop is connected with an anti-overflow pipe; a blowoff manifold is connected with the right side of the wellhead main four way; the outlet of the blowoff manifold is connected with a throttling manifold; a blowoff flat valve is arranged at the inlet of the throttling manifold; a reverse circulation manifold is connected with the left side of the wellhead main four way; a semi-sealing bop is a double gate disc bop composed of the semi-sealing large valve element flashboard and the semi-sealing small valve element flashboard; the large and small valve element flashboards are controlled by large and small valve element liquid rotary valves; an operating handle is connected with the piston rod of a semi-sealing air cylinder; compressed air is connected with a blowoff pneumatic control valve I, an annular pneumatic control valve and the ports P of semi-sealing large and small valve element pneumatic control valves; and the ports A of the semi-sealing large and small valve element pneumatic control valves are connected with the upper cavity gas ports of semi-sealing large and small valve element air cylinders through semi-sealing large and small valve element shuttle valves. The well drilling wellhead anti-overflow control system can realize soft closing for underground drilling tools withdifferent specifications.

Description

technical field [0001] The invention relates to a petroleum drilling safety device, in particular to a drilling wellhead overflow prevention control system, which is used for emergency well shutdown when overflow, well kick and blowout accidents occur during petroleum drilling, and belongs to the technical field of petroleum drilling blowout prevention. Background technique [0002] Wellhead blowout preventer includes full-sealed single ram, semi-sealed ram and annular blowout preventer, etc. It is used to close the wellhead during drilling and oil production to prevent blowout accidents. It is a safe and well-sealed wellhead device commonly used in oil fields to prevent blowouts . Fully sealed single ram, semi-closed ram and annular blowout preventer are installed above the main cross of the wellhead from bottom to top, and the top of the annular blowout preventer is connected with an upwardly extending anti-overflow pipe. The right side of the main cross at the wellhead i...

AI Technical Summary

Problems solved by technology

When the downhole structure is complex or the well is relatively deep, such as more than 6000m, the drill pipe usually has two sizes, the upper drill pipe is thicker, such as 5½ inches, and the lower drill pipe is thinner, such as 3½ inches. At this time, half of the single ram The blowout preventer can only be applied to one specification of drill pipe. When another specification of drill pipe is at the wellhead and a blowout occurs, the semi-sealed ram will either not be able to seal, or the drill pipe will be damaged.

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