METHOD OF CONSTRUCTION OF WELLS WITH LARGE DIAMETER Russian patent published in 2019 - IPC E21C27/22 E21D3/00 E21C25/16 

FIELD: mining.

SUBSTANCE: invention relates to mining, it is used for expansion of pilot wells at mining and extraction of minerals. Method of constructing wells with large diameter includes drilling a pilot well with a drill rig with a drill string, drilling of said pilot well to preset diameter by expander equipped with rock cutting tool and installed in lower part of drill string, removal of drill cuttings from transport and sorting working, at that, movement of expander is performed by means of winch with rope. Drilling machine and said winch with rope are installed on movable platform fixed above the constructed well. To drill pilot well, a tangential-percussion reamer is used, equipped with a centering device directed to pilot well, and rock-breaking tool in form of at least two blocks of movable elements, equipped with separate motors for rotation of shafts of said movable elements.

EFFECT: enabling increase in the pilot well drilling-up rate with the least energy-intensive expander action on the rock mass, enlarging the application area of the method by means of the pilot well drilling and with the day surface drilling, and using underground workings, using simple, less expensive and more wear-resistant equipment.

3 cl, 5 dwg