DEVICE FOR ISOLATION OF A COMPLICATION ZONE WITH PRE-FLUSHING Russian patent published in 2019 - IPC E21B29/10 

FIELD: oil and gas industry.

SUBSTANCE: invention relates to oil and gas industry, namely to devices for isolation of well borehole complication zone with preliminary flushing during drilling. Device includes profile shutter with cylindrical sections and threaded joints, inner mandrel arranged in upper cylindrical part of shutter, guide shoe, expanding head from several expanding sections installed one above another with decreasing diameter along working surfaces towards shutter, and containing from above unit for connection with drill string. In lower cylindrical part of shutter there is lower inner mandrel and lower sections are arranged in series below. Lower inner mandrel is connected by drill string with top inner mandrel. Valve is arranged inside shutter. Valve is made of hollow body with upper coupling and lower nipple threads, providing connection with drill pipes. In lower part of valve body inner hollow bushing is made integral with housing. In the upper and lower parts of the internal bushing the holes are made, which provide opening of the through central channel for liquid passage after expansion of the shutter with pressure. In upper part of valve body there are radial holes. In the upper part of the hollow valve body there is a movable bushing with radial holes and a seat for the ball, which is made with possibility of limited axial movement to align with radial holes of the valve body, which provides expansion of the shutter with pressure. In the lower part of the hollow valve body there is a movable stop installed in the through central channel of the case below the movable bushing with the possibility of axial movement by force of the movable bushing between the valve body and the internal hollow bushing. Movable bushing and movable stop are fixed with shear pins.

EFFECT: increased reliability of the device due to the possibility of continuous direct flushing of the well from the slurry due to the valve design, additional lifting equipment for installation of the shutter is excluded.

1 cl, 5 dwg