METHOD FOR DRILLING BOREHOLES WITH SIMULTANEOUS CASING Russian patent published in 2021 - IPC E21B7/20 

FIELD: mining.

SUBSTANCE: invention relates to mining equipment, namely to a method for drilling boreholes with simultaneous casing. The method includes destruction of the rock at the bottom of the borehole by means of a rotary-percussion impact thereon with a casing and drilling tool with a retractable head part, adapted for being extracted from the borehole, with simultaneous advancing of the casing in the direction of the bottom under the impact of shock pulses. Shock pulses are transmitted to the casing pipe outside of the inner diameter thereof by means of spring-loaded thrust spacers installed in the cavities of the casing and drilling tool thrust against the thrust surface in the front part of the bore of the supporting sleeve attached to the front part of the outer surface of the casing pipe and provided with a tapered surface in the rear part of the bore used to press the thrust spacers upon completion of drilling and move the spacers into the indicated cavities of the casing and drilling tool during removal thereof from the borehole. A supporting sleeve with the smallest inner diameter no less than the inner diameter of the casing pipe is used.

EFFECT: elimination of the narrowing of the inner diameter of the casing pipe is provided, allowing for further drilling through the casing pipe with the maximum possible diameter of the borehole.

1 cl, 1 dwg