Apparatus for restraining a tubing string during blowout and wellhead control method

Abstract

The invention provides a device for limiting an oil tube column during blowout and a well mouth control method. A plug valve is connected to the upper end of the oil tube column, the plug valve is sleeved with a wellhead blowout preventor, the device comprises a cover body connected with the wellhead blowout preventor, the cover body is provided with the containing space, and the containing spacecontains the plug valve when the cover body and the wellhead blowout preventor are connected; a stop part is arranged inside the cover body, the stop part has the projection area at least in the plugvalve direction, and therefore the stop part is provided with a stop face facing the plug valve, the stop face can fixedly abut against the upper end of the valve plug, and the oil tube column is limited when the plug valve is moved up due to blowout. According to the device for limiting the oil tube column during blowout and the well mouth control method, the out-of-control blowout event can be effectively avoided.

Description

technical field [0001] The invention relates to the technical field of oilfield well control, in particular to a device for restricting a tubing string during blowout and a wellhead control method. Background technique [0002] The statements in this section only provide background information related to the present disclosure and may not constitute prior art. [0003] At present, when the tubing is lifted and lowered in oil field workover operations, the well control equipment is mostly a semi-sealed ram blowout preventer connected with the large four-way flange, and the spraying equipment is mostly a tubing cock valve. When a blowout occurs, the oil pipe in the well is connected through the plug valve, and then the semi-sealed ram of the blowout preventer hugs the plug valve tightly, thereby sealing the annular space between the oil pipe and the casing. Close the oil pipe cock, seal the inner space of the oil pipe, and achieve the purpose of controlling the blowout danger...

AI Technical Summary

Problems solved by technology

[0004] However, if there is a sudden high-pressure fluid in the well, the high-pressure fluid will push the tubing string up, and the way the BOP controls the tubing string up is only to block the tubing collar through the half-sealed ram of the BOP

Once the jacking force of the tubing string is strong enough, the tubing string will break the semi-sealed ram and fly into the air, resulting in blowout out of control

At this time, if we want to control the blowout at the wellhead, it will be very difficult and the loss will be huge.

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