WELL DRILLING DEVICE Russian patent published in 2015 - IPC E21B7/00 E21B19/08 

FIELD: oil and gas industry.

SUBSTANCE: invention is related to drilling, and namely to water extraction from bore wells using the well drilling device by percussion rotary drilling. The well drilling device by percussion rotary drilling comprises a chisel weight magnifier installed directly over the chisel - above-chisel bit weighting material - fixed to the drill stem and the chisel bit by means of adaptors. The chisel weight magnifier is made as a section of casing pipe, which can be installed at the drill pipe thrusted to the adaptor that connects the drill pipe with a chisel bit at the one side and connection by the adaptor with the drill string at the other side, at that the casing pipe section is centred in regard to the drill pipe by means of protective couplings while the space between these pipes is filled with lead pellet.

EFFECT: improved efficiency of well drilling due to increased rate of drilling.

2 dwg