BYPASS VALVE FOR DOWNHOLE HYDRAULIC JACK Russian patent published in 2016 - IPC E21B34/10 E21B29/10 

FIELD: mining.

SUBSTANCE: invention relates to drilling and repair of oil and gas wells, in particular, is intended for isolation of troublesome zones when drilling wells with profile shutters. Bypass valve for downhole hydraulic jack is located above expanding head and below hydraulic jack, comprises a hollow-carrier bushing with cylindrical narrowing and a hollow rod inserted telescopically with possibility of restricted movement into carrier bushing and provided from below with a nipple with external seal. Nipple is made with possibility of tight overlapping of bypass hole when moving rod downward relative to carrier bushing, and carrier bushing and rod are connected to expanding head and hydraulic jack. Nipple is inserted tightly by outer seal in hollow rod with possibility of restricted upward movement and pressed with a spring downwards relative to rod, and bypass hole is made at bottom of nipple and is equipped with valve seat. Inside cylindrical narrowing there is an insert with valve from above, around which there are bypass channels. Valve is made with possibility of tight interaction with seat and overlapping bypass hole when moving rod downward relative to carrier bushing, and nipple in area of installation of spring is equipped with radial process openings.

EFFECT: technical result consists in improvement of reliability of valve.

1 cl, 1 dwg