TURBODRILL Russian patent published in 2006 - IPC E21B4/02 

FIELD: drilling equipment, particularly turbodrills for well drilling.

SUBSTANCE: turbodrill comprises body, shaft, support unit and multistage turbine. Turbine stators are fastened to the body. Rotors are connected to shaft. The turbine includes a number of stages including stator and rotor installed in the stator and spaced apart from it. The stator is provided with screw teeth formed on inner surface thereof. The rotor also has screw teeth created on inner rotor surface and defining screw line with hand opposite to that of line defined by spiral stator teeth to distribute drilling mud flow between valleys between rotor and stator teeth during turbodrill operation. Turbine additionally has at least one spacing ring installed between screw teeth of adjacent single rotor and stator stages correspondingly so that above teeth may rest upon the spacing ring. Spacing rings installed correspondingly between screw teeth of single rotor and stator stages are offset with respect to each other in axial turbine direction during turbodrill assemblage operation. The spacing rings are formed of antifriction material, for instance of Caprolon. Rotor and stator teeth sides subjected to flow energy action have concave surfaces. Opposite teeth sides have convex surfaces. Spacing ring sides are gently sloping with respect to turbine axis. Valleys defined by stator and rotor teeth converge in widthwise direction and radially extend in drilling mud flow direction. Total volume of valleys defined by single stage rotor teeth is 1.2-7.2 times as much as total volume of valleys defined by stator teeth of the same stage if rotor and stator have equal lengths.

EFFECT: increased turbodrill efficiency and simplified production thereof.

6 cl, 9 dwg