HYDROPERCUSSION DRILLING ASSEMBLY Russian patent published in 2006 - IPC E21B25/18 

FIELD: well drilling, particularly technical means adapted to drill underground wells in shelf and to obtain ground samples from soft rock deposits.

SUBSTANCE: hydropercussion drilling assembly comprises rotatable drill pipe including inner and outer core barrels with shoe and corer and hydrupercussion means with inlet channel to be connected with pressure source and liquid removal channel. The liquid removal channel is connected with space defined by core barrels communicated with well. Distribution adapter is arranged over hydropercussion means and provided with chamber having orifices connected with pressure source, inlet channel of hydropercussion means and with space between core barrels. Piston with axial channel and activation valve seat is installed in the chamber so that the piston may perform longitudinal movement. Chamber orifice connected with inlet hydropercussion means channel may be closed with side piston surface. Blocking valve is installed in hydraulic line between the chamber and the space defined by core barrels. The blocking valve may simultaneously divide the chamber and the space between core barrels and to communicate the chamber with space over annular slide. Cavity under annular slide is communicated with space between core barrels. Inner core pipe cavity may be connected with hydraulic line between the chamber and space between core barrels over blocking valves by orifices and annular slide. Piston may communicate chamber orifice connected with inlet hydropercussion means channel with pressure source and disconnect pressure source from chamber orifice communicated with space between core barrels.

EFFECT: increased depth of sample obtaining due to provision of preliminary drilling assembly deepening in ground without sample removal.

3 dwg