DEVICE FOR ISOLATION OF WELL DRILLING PROBLEMS ZONES BY SHUTTER WITH CYLINDRICAL SECTIONS Russian patent published in 2014 - IPC E21B29/10 

FIELD: oil-and-gas industry.

SUBSTANCE: invention relates to isolation of drilling problem zones. Proposed device comprises shaped shutter, shoe with check valve, expanding head of several sections, anchor assembly, hydraulic jack composed of piston with hollow rod and cylinder. After shutter is lowered in the well and expanding is by hydraulic pressure, shaped sections are expanded and gaged by lengthwise displacement of expanding head composed of punches under gravity of pipe string and by hydraulic jack, if required. Note here that force preventing the pipe string push-out at hydraulic jack operation is developed by hydraulic anchor. For efficient operation of hydraulic jack and anchor, this device exploits a pre-tunable hydraulic valve to activate hydraulic jack and anchor at expansion of cylindrical sections of shutter. Said valve comprises seat arranged outside the rod and pressed there against by spring at adjustable force. Hollow rod is equipped with extra valve that transmits from outside to inside.

EFFECT: higher reliability and efficiency.

2 cl, 8 dwg