METHOD AND DEVICE FOR ISOLATION OF TROUBLESOME ZONES WHEN DRILLING WELLS WITH SHAPED SHUTTER WITH CYLINDRICAL SECTIONS Russian patent published in 2013 - IPC E21B33/10 E21B43/10 

FIELD: oil and gas industry.

SUBSTANCE: when implementing the method, a shutter is lowered to a troublesome zone, shaped sections of the shutter are expanded by creating hydraulic pressure in it and calibrated by means of sections of the expanding head, which are made in the form of puncheons, in a downward direction by pushing through the shutter with the weight of a pipe string, and with a hydraulic jack in the sections requiring additional forces. Besides, prior to lowering, one or more hinge assemblies are installed between the sections, and pressure drop in the hydraulic jack and the last puncheon in relation to the shutter is created due to nozzles. At that, force of the hydraulic jack fixation relative to the well is created with the weight of the pipe string or due to friction of those pipes on the well walls. The device includes a shaped shutter, sections of the expanding head, and a hydraulic jack with a central channel, which is connected to upper end of the shutter. Nozzles are installed inside the expanding head, and one or more hinge assemblies are arranged between its sections.

EFFECT: avoiding the probability of tool sticking owing to shortening the length and application of hinge assemblies increasing the tool flexibility, and allowing to reduce time expenditures when isolating the well troublesome zones.

2 cl, 4 dwg