Turbodrill

Abstract

A turbodrill comprises a housing coupled with its one end to a drill pipe for feeding drilling fluid, the housing accommodating a hydraulic downhole motor comprising a multistage turbine. Each stage of the multistage turbine comprises a directing stator disk defining through passages and a working rotor disk defining through passages, the rotor disk being installed on a shaft. The shaft is rotatably mounted in the housing on supports and carries a rock breaking tool on the end thereof facing the bottomhole. The total area of the inlet openings of the stator disk through passages is from about ⅕ to about ⅗ of the total area of the inlet openings of the rotor disk through passages.

1 . A turbodrill in combination with a drill pipe comprising: 
 a housing which is a bearing member and has two ends, one of said ends being coupled to said drill pipe;    a hydraulic downhole motor arranged in said housing;    a multistage turbine of said hydraulic downhole motor;    a directing stator disk of said multistage turbine, secured in said housing;    supports installed in said housing;    a shaft rotatably mounted in said housing on said supports, having an axis and a carrying end facing the bottomhole;    a working rotor disk of said multistage turbine disposed on said shaft;    each stage of said multistage turbine constitututed by said directing stator disk and working rotor disk, installed sequentially downstream the drilling fluid;    through passages formed in said directing stator disk;    through passages formed in said working rotor disk;    inlet openings of said through passages in said working rotor disk;    inlet openings of said through passages in said directing stator disk, the total area of said inlet openings of said through passages in said directing stator disk being from about ⅕ to about ⅗ of the total area of said inlet openings of said through passages in said working rotor disk;    a rock breaking tool secured on said carrying end of said shaft.    
     
     
         2 . A turbodrill according to  claim 1 , comprising: 
 a diametral plane, in which there lie said inlet openings of said through passages in said directing stator disk of said each stage;    a through axial duct formed by said inlet openings of said through passages in said directing stator disk of said each stage, lying in said diametral plane, said duct having a longitudinal axis parallel to said axis of said shaft.    
     
     
         3 . A turbodrill according to  claim 1 , wherein said inlet openings of said through passages of said directing stator disk of said each stage being subsequent with respect to the incoming flow of the drilling fluid are displaced circumferentially through at least 1 degree relative to said inlet openings of said through passages of said directing stator disk of said each preceding stage, so that said outlet openings of said through passages of said directing stator disk of all the stages of said multistage turbine are disposed along a helical line with a center lying on said axis of said shaft.  
     
     
         4 . A turbodrill according to  claim 2 , wherein said inlet openings of said through passages of said directing stator disk of said each stage being subsequent with respect to the incoming flow of the drilling fluid are displaced circumferentially through at least 1 degree relative to said inlet openings of said through passages of said directing stator disk of said each preceding stage, so that said cutlet openings of said through passages of said directing stator disk of all the stages of said multistage turbine are disposed along a helical line with a center lying on said axis of said shaft.