DEVICE FOR TESTING CASING STRING FOR TIGHTNESS Russian patent published in 1995 - IPC

FIELD: well drilling. SUBSTANCE: device for testing casing string for tightness has support to which body with axial channel and through holes in wall is connected. Mounted on body outer surface is movable piston with shell which covers holes in body wall in its initial position. Arranged on body between piston and support is sealing member made of flexible material and engageable with piston. Connected to body lower end face is branch pipe whose upper part has stepped bore. Bore upper step has through holes in branch pipe wall and movable stepped bushing with seat for drop ball. Made in lower part of branch pipe is bore to receive movable spring-loaded sleeve. Axial channel between upper and lower bores of branch pipe is made in its wall. EFFECT: higher efficiency. 3 dwg