WELL CONSTRUCTION METHOD Russian patent published in 2013 - IPC E21B7/00 E21B33/14 

FIELD: mining.

SUBSTANCE: well construction method involves well shaft drilling, installation of cement bridge in the rock falling zone, performance of process exposure for cement setting, drilling of cement bridge and continued well drilling. All falling zones are drilled and cement bridges are installed sequentially at falling intervals in upward direction. When cement bridge is being installed at lower interval, cement material with lower strength and larger setting time is used than that used during installation of cement bridge at upper interval. Fluid bridge with density of 1.10-1.35 g/cm³ is installed between cement bridges. Cement material setting speeds are chosen based on similar strength of cement stone by the moment of the beginning of drilling process of each cement bridge.

EFFECT: possible construction of the well passing through two and more rock falling zones.