METHOD OF WELL CONSTRUCTION WITH ZONES OF COMPLICATIONS Russian patent published in 2017 - IPC E21B33/13 

FIELD: oil and gas industry.

SUBSTANCE: invention relates to oil and gas industry, namely to methods of construction of wells at drilling intervals with zones of complications. Method involves drilling of wells in intervals of well shaft with zones of complications and strengthening of well walls by shaped shutters series with sections of decrease of internal diameter of the installed profile shutters. Opening sections is selected in different intervals of the well shaft with zones of complications and overlap them by profile shutters completely at one lowering-lifting operation. Shutters are installed with spacing between them. After the lower shutter is drilled borehole with diameter allowing to install casing string with required diameter. First section of opening below the conductor is made by maximum possible diameter of the bit. Shaped shutters are installed in the well immediately after opening the troublesome zone till mud-filtrate saturation of unstable rocks. For this purpose, expansion of the well shaft and calipering is not performed. Wall thickness of the shaped shutters is selected from the condition of exposure to said shutters of internal and external pressure.

EFFECT: increasing of reliability of insulation of trouble zones, as well as essential reduction of time for well construction and material costs.

1 cl, 1 dwg