DRAINAGE METHOD OF OPEN PIT EDGES BY MEANS OF SYSTEMS OF COMBINED DRAINAGE DEVICES Russian patent published in 2012 - IPC E02D19/00 

FIELD: mining.

SUBSTANCE: drainage method of open pit edges by means of systems of combined drainage devices involves system of combined drainage devices arranged from the side of the open pit bench normally to the edge at soil of water-bearing horizon and consisting of horizontal branch of drain hole and the branch that is close to vertical position, which are equipped with flexible filter. Length of horizontal part is determined considering the entry way value and technical capabilities of the used drilling equipment. Change-over of horizontal branch of the device to vertical position is performed by means of bottom-hole motor and diverting devices. Length of vertical part of combined device is determined depending on capacity of drained water-bearing horizon; therefore, sinking of vertical branch of drainage device ends after the working face enters the rocks of waterproof roof of drained formation. Drilling of combined drainage device in incompetent rocks, for example, sands is performed in step-by-step horizontal part of the shaft under protection of "blind" inventory column of casing pipes, and then removed pipes; sinking of vertical branch of drainage device is performed using self-decomposing or hydrolysed polyacrylonitrile drilling fluids in order to provide the stability of its walls. After sinking of vertical part of the shaft is completed, rock-destructing tool is disconnected and left in solid mass, and bottom-hole motor is removed along shaft of combined device, which is fixed with filter. Drainage water is discharged via the system of the trenches near the edges.

EFFECT: reduction of drilling volumes of drain holes; improvement of reliability of drainage systems, stability of edges of open pits and safety of mining operations; reduction of material consumption and costs for drainage of open pit edges.

3 dwg