TURBODRILL TURBINE Russian patent published in 2006 - IPC E21B4/02 F03B13/02 

FIELD: oil and gas well drilling equipment, particularly axial flow turbine of multistage turbodrill.

SUBSTANCE: turbodrill turbine comprises stator with blade ring and inner rim, rotor with blade ring and hub. Design angles of stator flow inlet and outlet directions α₂ and α₁ and rotor flow inlet and outlet directions β₂ and β₁ are related by theoretical correlations with peripheral velocity determined in idle and optimal (shock-free) mode of turbine operation. Stator and rotor blade ring blades defining above design angles as distinct from prior art turbines are formed so that shock-free regime of flow around the stator and the rotor is realized at different peripheral velocities, wherein above shock-free regime of stator flow-around is performed in retardation mode, shock-free regime of rotor flow-around is performed in runaway mode thereof. Above stator and rotor angles are correlated as α₁<α₂≤π/2 and β₂<β₁≤π/2 (in the case of positive reactive turbine) and β₁<β₂≤π/2 (for negative reactive turbine). The stator rim has surface of lesser diameter having conoid shape and converging towards lower cross-section thereof so that minimal annular gap defined by rotor hub is 0.05-0.3, preferably 0.1-0.2 of radial stator blade height and inner blade ring surface of lesser diameter has conoid shape and is converged to upper section so that radial rotor blade height ratio in lower and upper sections is equal to 0.7 - 0.95.

EFFECT: increased axial support resistance along with increased performance.

5 cl, 8 dwg