TOOL FOR WELL DRILLING Russian patent published in 1997 - IPC

FIELD: tools for well drilling. SUBSTANCE: tool includes drill pipe string whose lower part is connected to turbodrill body by means of sub, and drill bit connected to turbodrill shaft. Turbodrill shaft is secured in turbodrill body with the help of axial and radial bearings. Turbodrill working members include: bladings of turbine pressure stage; turbodrill axial and radial bearings fixed in its body with the aid of tensioned threaded sub. Connected to sub lower end is diamond drill crown. Drill bit is located inside body of diamond drill crown. Outside drill bit diameter is larger than inside diameter of tensioned threaded sub by 0.003-0.40 m. EFFECT: higher efficiency. 1 dwg