DOWNHOLE VALVE UNIT Russian patent published in 2016 - IPC E21B34/08 

FIELD: mining.

SUBSTANCE: invention relates to equipment of wells equipped with downhole electrically driven pumps. Device includes housing with annular projection on inner surface, below which has drain channels, movable in axial direction of slide valve with upper and lower shanks of smaller diameter. In upper part of upper shank are drain openings and there is a limiting collar, while lower shank of spool is sealed relative to housing. Furthermore, spool is equipped with through axial channel where there is a check valve and installed in housing to make annular starting chamber, in which on upper shank is arranged axially moving two-stage piston upper step of which there is a hollow cylinder in walls of which there are collets and drain openings. Hollow cylinder is rigidly connected and combined outer side with upper step of axially moving two-diameter piston, and on inner side of upper step of axially moving two-diameter piston forms an annular setting projection made with possibility of tight fit limiting collar upper shank of spool. Furthermore, annular starting chamber communicates with axial channel of spool by holes in lower part of upper shank. Lower outer surface of larger diameter step of axially moving two-diameter piston has possibility of sealing relative to housing inner surface. And upper stage is designed to shut off drain channels of housing and to seal relative to housing annular projection in uppermost position of piston. Furthermore, collets are installed with possibility of interaction with annular projection of housing and with limiting collar. Area bounded by compacted sides stages of axially moving two-diameter piston is made with possibility of exceeding area bounded by outer diameter of lower shank of the spool. At lower shank of spool there is a pressure relief valve with spring-loaded shutoff member and configured to release pressure from launching chamber and axial channel of spool. Adjusting sleeve is installed on housing. Adjusting sleeve is installed with possibility of interacting with shutoff member pressure release valve when pressure pulse to open message inner cavity of tubing string with annular space.

EFFECT: technical result consists in improvement of reliability.

1 cl, 3 dwg