CIRCULATION UNIT FOR CASING LINER Russian patent published in 2014 - IPC E21B33/14 

FIELD: construction.

SUBSTANCE: circulation unit for a casing liner comprises a housing placed in the bottom part of a transport column above the unit of its coupling with the liner. The housing is made with a filling hole in the bottom part, overlapped by a shear sleeve and a circulation hole in the top part. A sealing member is placed on the housing. The circulation unit comprises an injector with a circulation hole placed on the housing above the sealing member and overlapping the circulation hole of the housing. There is a distribution sleeve with a radial opening, a peripheral axial channel and a catching baffle in its lower part. In this case the distribution sleeve is placed in the housing and designed with a possibility to provide the direct circulation of fluid through its axial channel with displacement of the fluid in space behind the liner, housing and above it - in the transport position of the device. Also, with a possibility of deformation of the sealing member by means of the injector and assurance of injection of a cement slurry through its axial channel, radial openings aligned with the filling opening, into the space behind the housing and below it, behind the liner according to the reverse circulation pattern with displacement of the fluid through the peripheral axial channel, space between the housing and the distribution sleeve, combined circulating openings of the housing and the injector into the space behind this injector and above it - in the operating position of the device.

EFFECT: increased reliability of the device operation.

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