RIGIDLY ORIENTED OFF-CENTER MOUNT FOR DRILL PIPE STRING (VERSIONS) Russian patent published in 2001 - IPC

FIELD: drilling equipment. SUBSTANCE: invention is related to devices ensuring eccentric position of drill pipe string in horizontal, inclined and vertical sections of hole. Off-center mount has body and bushing with recesses and bosses of various height mounted it for rotation. Lower and center bosses have shape of helical lines, lower bosses being arranged in mirror symmetry on both sides of off- center mount forming with it left spiral on one side and right spiral on other side. Bushing is put for fixing by means of lockpins. Recesses of bushing have through holes and body has proper sockets to accommodate lockpins. In correspondence with another version bushing with bosses of various height and recesses with through holes for lockpins is put on to internal bushing having same thickness over entire perimeter which is provided with holes for lockpins and is rigidly fixed on drill pope string. EFFECT: improved conditions for removal of slime, reduced pressure loss and prevention of dune formation and seizure. 3 cl, 6 dwg