The invention relates to torque self-balancing nested double
drill bits and belongs to the field of
well drilling and exploiting. The double
drill bits are composed of inner
drill bit bodies, outer
drill bit bodies and inner and outer
drill bit correcting wear-proof casings. Each inner
drill bit body is composed of an inner drill bit
cutting tooth, an inner drill bit
water gap, an inner drill bit outer step, an inner drill bit
rigid body and a flow jetting hole. Each outer drill bit body is composed of an outer drill bit
cutting tooth, an outer drill bit
water gap, an outer drill bit inner step and an outer drill bit
rigid body. Each inner and outer drill bit correcting wear-proof casing is composed of a body and a lubricating body through
interference fit, and the lubricating bodies are arranged in a full-covering mode in the axial directions of the bodies. According to the torque self-balancing nested double drill bits, stratum
rock breaking and torque balancing of the inner drill bit bodies and the outer drill bit bodies are achieved through reverse rotation of the inner drill bit bodies and the outer drill bit bodies, disturbance to surrounding rocks and hole walls is small, and the requirements for the double drill bits of a down hole torque self-balancing cable-containing drilling tool
system can be met.