| 摘要 |
FIELD: process engineering.SUBSTANCE: set of invention relates to hybrid drill bits. Drill bit comprises body for connection to drill string, at least one fixed blade extending downward from drill bit body and provided with radially remote gaging surface. Several fixed cutters are secured to fixed blade. At least one bit leg is attached to bit body. Roller cone is arranged at drill bit leg to run thereat. At least one stabilising strap is fitted between at least one bit leg and at least one stabilising blade to extend radially outward to, in fact, aforesaid gaging surface.EFFECT: stabilised drill bit, hence improved drilling performances.31 cl, 8 dwg |
