Drilling wellhead overflow prevention control system

Abstract

The invention relates to a wellhead overflow prevention control system for drilling, which comprises semi-sealed large and small spool double rams located on the main cross of the wellhead, a fully-sealed single ram and an annular blowout preventer, the top of which is connected with an overflow prevention pipe ;The right side of the main cross at the wellhead is connected with a discharge manifold, the outlet of the discharge manifold is connected with a throttle manifold, and the entrance of the throttle manifold is equipped with a discharge flat valve; the left side of the main cross at the wellhead is connected There is a reverse circulation manifold; the semi-sealed blowout preventer is a double-slide preventer composed of a semi-sealed large spool gate and a semi-sealed small spool gate. The large and small spool gates are controlled by the large and small spool liquid rotation valve, its operating handle is connected with the piston rod of the semi-sealed cylinder; the compressed air is respectively connected with the P port of the spray air control valve 1, the annular air control valve, and the semi-sealed large and small spool air control valve; the semi-sealed large and small spool air The A port of the control valve is connected with the upper cavity air port of the semi-sealed large and small spool cylinder through the semi-sealed large and small spool shuttle valves. The device can realize soft shut-in for drilling tools of different specifications downhole.

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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