Expandable fracture packer for preventing midway setting

Abstract

The invention discloses an expandable fracture packer for preventing midway setting. The expandable fracture packer comprises an upper connector, an upper sealing ring of a slide bushing, a piston, a control dowel, a lower sealing ring of the slide bushing, the slide bushing, an upper sealing ring, a check valve, a valve, a sealing barrel, an inner pipe, a rubber barrel, a lower sealing ring and a lower connector. The slide bushing covers an inner joint through hole in the valve, and a gap between the slide bushing and the valve is sealed by the upper sealing ring of the slide bushing and the lower sealing ring of the slide bushing. The expandable fracture packer has the advantages that water impact pressures generated due to excessively high speeds during descending can be prevented from being transmitted into the rubber barrel, accordingly, the problem of damage to an existing rubber barrel due to midway setting can be solved, and problems at present can be solved; shrinkage of the rubber barrel and releasing of the packer can be prevented when fracture is stopped, repeated shrinkage and expansion of the rubber barrel can be prevented, accordingly, the rubber barrel can be prevented from being damaged, the packer is long in service life, the fracture frequencies can be increased, successful separate-layer fracture can be guaranteed, and economic benefits can be increased.

Description

technical field [0001] The invention is a downhole layered water injection tool for water injection in an oil field, and is an expansion type fracturing packer for preventing midway sealing. Background technique [0002] At present, oil field fracturing of separate layers adopts expansion water injection packer for oil field water injection. The expansion type water injection packer used for oilfield water injection is to expand the rubber sleeve outward when the internal pressure of the rubber sleeve is higher than the external pressure of the rubber sleeve, so as to achieve the purpose of sealing the annular space of the oil casing. When the expandable water injection packer is to be pulled out from the well, the pressure inside the rubber tube needs to be equal to or less than the external pressure of the rubber tube to make the rubber tube shrink. In order to change the pressure inside and outside the rubber cylinder, the expansion water injection packer is provided wit...

AI Technical Summary

Problems solved by technology

The above-mentioned packer cannot overcome the problem of the expansion of the rubber cartridge in the process of lowering

Because a check valve is installed at the lower part of the string with a packer, the liquid flow outside the string can only enter the string, and cannot flow from the inside to the outside of the string. Because sometimes the speed of going downhole is not well controlled, the If the speed is too fast, the tubing pressure is often much higher than the casing pressure in an instant. At this time, the problem of sealing the rubber cartridge in the middle of expansion will occur. The rubber cartridge is easily damaged under the downward thrust of the pipe string. Therefore, layered fracturing Layered fracturing cannot be achieved with expansion water injection packers used for oilfield water injection

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