Abstract: A turbodrill comprising turbine sections, a spindle and a pipe assembly. According to the invention, the pipe assembly is formed by two coaxially arranged pipes provided between the spindle and the adjacent turbine section and coupled to components of the turbodrill.

Abstract: The turbodrill disclosed consists of a shell (1) attached to the drilling string and provided with an opening (3) in the side surface, a multistage turbine and a hollow shaft (6) supported in the shell (1) by radial bearings (10) and a thrust bearing (11). The bore (7) of the shaft (6) is hydraulically linked up with the drilling string (2) and with a space (15) provided above the nozzles of the bit (13). Seals (16, 17) keeping the drilling fluid out of the space (12) contained where the thrust bearings (11) are provided in an annular space between the shell (1) and the shaft (6).The present invention can be used to advantage in turbodrills employed for the drilling of deep oil and natural gas wells under difficult geological conditions.