TURBODRILL TURBINE Russian patent published in 2008 - IPC E21B4/02 

FIELD: technical means for oil and gas well drilling, particularly axial flow turbines included in multistage turbodrills.

SUBSTANCE: turbine comprises stators and rotors with blade rows having axial heights, which are 25-30% less than that of turbines having cascades of the same profile type and of the same specific speed and having pitch ratio, namely ratio between blade spacing to blade chord, which does not exceed optimal value range of 0.65-0.9 with ratio between rotor and stator relative blade spacing of up to 0.92 - 0.98 and more. Inner surface of stator blade row having greater diameter and that of rotor blade row having lesser diameter are conical and formed so that ratio between radial blade heights at stator output and rotor output and radial heights of the same blades at inputs thereof is within 0.9-0.65. The greater is relative pitch of turbine with decreased axial height, the lesser is said ratio.

EFFECT: increased energy output, decreased axial turbodrill length or increased torque thereof.

4 dwg