DEVICE FOR TREATMENT OF BOTTOM-HOLE FORMATION ZONE AND FOR WELL DEVELOPMENT Russian patent published in 2015 - IPC E21B43/25 E21B28/00 

FIELD: oil and gas industry.

SUBSTANCE: device for treatment of bottomhole formation zone and well development includes pipe string run in hole with baffle collar complete with opening as well as piston valve. The piston valve consists of a body with cup and gate from bellow. The pipe string forms annular space with production string. The piston valve is installed in the pipe string so that is may be moved axially until it interacts with baffle collar and closes opening of baffle collar by gate of the piston valve. From bellow the baffle collar is equipped with shank and packer mounted on it. At that the packer may be set over the formation in the production string with separation of annular space and over-packer space in the well. In the shank above the packer there are openings, wherein there are rigidly fixed tubes interconnecting the annular space with a nozzle placed concentrically in the shank. At that in the shank opposite the nozzle there is low-pressure chamber, which is connected through inner space of the shank with below-packer space of the well. Ejector is mounted in the shank under the nozzle. The piston valve body is equipped with three support rings made as outer cylindrical cut-outs. At that two support rings are coated with rubber into a cup and the third support ring is coated with rubber into the gate. The cup is self-sealing and has two directions of operation, while the gate of the piston valve is made as a rubber plug capable of hermetic interaction with opening in the baffle collar.

EFFECT: improved efficiency of the bottomhole formation zone and operational reliability of the piston valve, improved efficiency in cleanout of the bottomhole formation zone in wells with low formation pressure.

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