DEVICE INTENDED FOR CEMENTING CASING STRINGS IN WELLS Russian patent published in 2010 - IPC E21B33/14 

FIELD: oil and gas production.

SUBSTANCE: invention includes two-piece body containing upper and lower parts. In upper body part there located are fabrication holes overlapped from outside with spring-loaded differential sleeve fixed with shear screw under which a stop screw is located. In lower body part there made is fabrication hole in which a check valve is installed and which is interconnected with packer and overlapped with tubular sealing element made from plastic material. Between upper and lower body parts there arranged is connection pipe whereon V-shaped sealing cuffs are installed. At stepped increase of internal pressure of the device, subsequent actuation is performed, first, of packer, and then, of differential sleeve, with further opening of fabrication holes and cementing of casing string space. At that, V-shaped cuffs provide maximum tightness at well wall contact.

EFFECT: improving reliability of separation of beds in wells when cementing casing strings, including the ones hidden in side well bores owing to simplifying the device design, reducing the time required for process operations when cementing casing strings.

3 dwg