DEVICE FOR WELL DRILLING BY APPLICATION OF ROTARY-PERCUSSION METHOD Russian patent published in 2015 - IPC E21B7/00 E21B19/08 

FIELD: mining.

SUBSTANCE: device includes a drilling bit weight enlarging mechanism installed immediately above the drilling bit - an above-bit weighting device - and attached to a drill string and to the bit by means of adapters. The bit weight enlarging mechanism is made in the form of a piece of a casing pipe that can be installed on a drill pipe so that it is borne against an adapter attaching the drill pipe to the bit on one side and connected by means of the adapter to the drill string on the other side; with that, a piece of the casing pipe is aligned relative to the drill pipe by means of safety couplings, and space between these pipes is filled with lead shots and electrorheological liquid and equipped with an electric field creation device increasing viscosity of electrorheological liquid when striking on the bit.

EFFECT: improving well drilling efficiency due to increase of driving speed.

2 dwg