Attachment-to-wall concealed drilling-free blind flange well cementation device

Abstract

The invention provides an attachment-to-wall concealed drilling-free blind flange well cementation device. The well cementation device comprises an upper pressing ring, a lower pressing ring and a blind flange pressed between the upper pressing ring and the lower pressing ring. A sliding sleeve is arranged on the inner side of the upper pressing ring and can move to the lower pressing ring from the upper pressing ring. The sliding sleeve is provided with a first position and a second position, wherein the first position is located above the blind flange, and the second position is used for clamping the broken blind flange between the sliding sleeve and the lower pressing ring when the sliding sleeve slides downwards to the lower pressing ring. The blind flange is broken through pressure build-up of a well mouth without lowering a drilling tool for removing the blind flange through drilling, and therefore well cementation completion operation time is shortened, and the well cementation completion operation cost is lowered; the broken blind flange is attached to and concealed in the inner wall of a casing string through the sliding sleeve, and therefore the drift diameter of the casing string is guaranteed, and it is effectively avoided that in the follow-up operation, fragments of the broken blind flange are hung on a production pipe column and block the production pipe column; the attachment-to-wall concealed drilling-free blind flange well cementation device is simple in structure, reliable in installation, convenient to use and low in cost.

Description

technical field

[0001] The invention relates to a downhole tool in the field of petroleum and natural gas, in particular to a wall-attached hidden drilling-free blind plate cementing device for selective well cementing and floating casing operation. Background technique

[0002] In the development of oil and gas, for high-inclination wells, especially horizontal wells, due to the high friction of casing running, it is difficult to run the casing and the casing wear is serious. It is necessary to carry out casing floating operations. To establish the liquid pressure in the pipe, install the blind plate in the pipe string to ensure the pressure of the liquid in the pipe above the blind plate. After construction, drill the blind plate to ensure the smoothness of the pipe. Drilling off the blind plate in the pipe will increase the operating time and cost. In view of this, the "drill-free blind plate" has been researched and developed. By setting the blind plate to be broken unde...

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