Displacement controlled resetting self-grouting blind plate

Abstract

The invention provides a displacement controlled resetting self-grouting blind plate and belongs to the field of well completion of the petroleum industry. The displacement controlled resetting self-grouting blind plate comprises an external cylinder, a shearing pin, an upper sealing ring, a lower sealing ring, a closing sleeve and an internal supporting body, wherein the internal supporting body is fixed in the external cylinder; the internal supporting body is provided with an annular axial supporting body and a round radial supporting body; at least one fluid flowing channel communicated with the bottom of the round radial supporting body is formed on the annular axial supporting body; the closing sleeve is arranged on the inner wall of the annular axial supporting body and fixed to the same via the shearing pin; the upper and lower sealing rings are embedded on the outer wall of the closing sleeve; and when the closing sleeve downwardly moves to a place blocked by the round radial supporting body, the upper and lower sealing rings and the closing sleeve seal the fluid flow channel. An arrangement of a seat-sealing valve is unnecessary, and the blind plate can be closed via increase of the displacement; a self-grouting function is provided, so automatic grouting upon casing pipe releasing and midway circulation during the releasing of the casing pipe; and a function of the blind plate can be restored after the casing pipe is released.

Description

technical field [0001] The invention relates to the field of well completion in the petroleum industry, and is mainly used in special well completion and cementing processes, especially for automatic grouting during casing running, circulation in the middle of the casing running process, and recovery of the function of the blind plate after casing running . Background technique [0002] At present, in some special well completion and cementing operations, it is necessary to install a blind plate in the casing string. The function of the blind plate is to form a seal at the bottom of the casing and close the circulation channel. After the bottom of the casing is closed, the wellhead pressure can be used to control the operation of the packer, grading hoop and other tools placed in the pipe string above the blind plate. [0003] There are two types of existing blind plates: one is an ordinary plug, which can only play a plugging role, and cannot be automatically grouted and c...

AI Technical Summary

Problems solved by technology

[0003] There are two types of existing blind plates: one is an ordinary plug, which can only play a plugging role, and cannot be automatically grouted and circulated during the casing running process. It is very risky for complex wells and deep wells. Serious Sometimes it will cause engineering accidents; the other type is the blind plate that can be circulated, such as an invention patent titled "circulating drilling-free blind cementing device", which proposes a recyclable drilling-free blind When the casing is blocked, the pump can be turned on and circulated at any time to release the card. When the casing is lowered to the designated position, the pump is turned on and circulated, and the seat is put into the valve seat to seal the circulation channel.

However, the biggest defect of this invention patent is that when the circulation channel is closed, valves need to be put in, and when the valves are lowered in the casing, they may not be completely seated on the valve seat, resulting in a loose seat seal, which is harmful to Subsequent control operations have a greater impact; in addition, it takes time to invest in Val, which may cause downhole complications; in addition, it is impossible to invest in Val in inclined wells and horizontal wells

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