METHOD FOR CONDUCTOR DRILLING OF WELL DISASTROUS LOST CIRCULATION AND DEVICE FOR ITS IMPLEMENTATION Russian patent published in 2015 - IPC E21B21/00 

FIELD: oil and gas industry.

SUBSTANCE: method includes cyclic process of conductor drilling of a well by drilling tool with water flush without circulation, with stops for water taking to suction pits. During cycle stops for water taking the drilling tool is removed with drilling bit from the well is removed and a pump at the drill string is run in and set at the level per 10-20 m lower than formation water standing level in the well, at the wellhead top end of the process string is bound to suction pits. The pump is started and formation water is taken to suction pits from the well, upon their filling the pump is switched off, the drill string with pump is run out from the well, the drilling tool with drilling bit is run in and top end of the drilling tool is bound to suction pits; drilling is continued in the interval of disastrous lost circulation zone with flushing by formation water until water from suction pits is consumed. Then the above cycle of making stop for formation water intake to suction pits and drilling is repeated.

EFFECT: reduced duration of the process without loss in efficiency; no auxiliary equipment is required.

2 cl, 2 dwg