Closable self-sealing loop isolation tool

Abstract

The invention discloses a closable self-sealing cycle packer tool. The tool comprises a self-sealing sand prevention cycle short-section component and a seal short-section component, and the self-sealing sand prevention cycle short-section component and the seal short-section component are connected to be an integrity through a connection tube which is arranged on the outer walls of the self-sealing sand prevention cycle short-section component and the seal short-section component in a sleeving mode; a sand clean-out pipe column is connected to a seal wellhead through an upper joint, and the sand clean-out pipe column is connected to sand surface through the lower end of a lower joint. After shear pins of the self-sealing sand prevention cycle short-section component are cut through, a sliding sleeve can run down in the axis direction to close a cycle short-section. A sand prevention sleeve is used for protecting cycle holes of the cycle short-section. A self-sealing valve can be opened by building the pressure, and the upper end and the lower end of a pipeline of the valve can be communicated. The seal short-section component is attached to the inner wall of an isolation pipe column, so that the annular space between the sand clean-out pipe column and the isolation pipe column is blocked, and circulation of sand clean-out mediums is prevented. The sand clean-out mediums are injected from the wellheads and pass through the annular space between the sand clean-out pipe column and the isolation pipe column at the upper end of the closable self-sealing cycle packer tool, the sand clean-out mediums can only enter the sand clean-out pipe column through the cycle holes of the cycle short-section, finally spray out from a sand clean-out head and return to the wellhead through the annular space between the isolation pipe column and a completion pipe column, and thus the situation that when a joint is made up, the construction of the sand clean-out pipe column continues without pumping off is achieved.

Description

technical field [0001] The invention relates to the sand flushing technology of coal bed gas wells, in particular to a closed and self-sealing circulation isolation tool. Background technique [0002] At present, domestic coalbed methane wells are mostly completed with casing or screen pipes. During the mining process, coal ash enters the wellbore along with the coalbed methane and gradually accumulates, affecting gas production. Regular sand washing is required. The existing domestic sand washing technologies mainly include coiled tubing sand washing technology and conventional tubing sand washing technology. [0003] Coiled tubing is used for sand washing, the cost of equipment is high, and good economic benefits cannot be achieved, while for conventional oil tubing for sand washing, the sand washing medium is injected through the wellhead tubing, and the pump needs to be stopped for single connection, and the sand washing process is discontinuous. At this time, the pulver...

AI Technical Summary

Problems solved by technology

[0003] Coiled tubing is used for sand washing, the cost of equipment is high, and good economic benefits cannot be achieved, while for conventional oil tubing for sand washing, the sand washing medium is injected through the wellhead tubing, and the pump needs to be stopped for single connection, and the sand washing process is discontinuous. At this time, the pulverized coal Falling back, prone to the risk of sand jams

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