Torque self-balancing nested double drill bits

Abstract

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.

Description

technical field [0001] The invention belongs to the field of drilling and drilling, and relates to a drill bit, in particular to a torque self-balancing nested double drill bit. Background technique [0002] During the drilling process, the drill string is deformed into a helical shape under the action of torque, and it collides with the well wall during rotation. Wear and alternating loads can easily damage the drill string in advance, resulting in in-hole accidents such as broken drilling tools. The occurrence of the accident brought huge losses to the entire project. As the drilling depth increases, the length of the drill string increases, and the proportion of energy lost by the drill pipe to overcome various frictional resistances in the well increases during the process of transmitting drilling pressure and torque. Therefore, the upper drilling rig is required to provide greater torque. When the well depth reaches a certain depth, downhole power tools must be added n...

AI Technical Summary

Problems solved by technology

If the drill bit encounters a broken formation, the inherent bonding force of the surrounding rock cannot provide enough anti-torque torque for the rock in contact with the drill bit, and the massive structure breaks away from the well wall. In addition, the circulating mud rotates with the drill string to generate local turbulence to stir the well wall. At this time, it will lead to the consequences of expanding the wellbore; when the drill bit encounters hard large-grained conglomerate, the sliding of the gravel can easily enter the nozzle of the drill bit and bridge with other gravels to generate a huge moment, which can easily lead to the collapse of the cutting teeth of the drill bit

Aiming at the current technical difficulties and deficiencies of many accidents and high costs in the well, it is necessary to propose a downhole torque self-balancing cabled drilling tool system, which fundamentally solves the reverse torque hazard caused by the rotary drilling of the drill string and changes the unidirectional rock breaking of the drill bit. To disturb the strength of the surrounding rock, simplify the ground drilling equipment and supporting tools and techniques, and achieve the goals of less accidents in the well, low drilling cost, low energy consumption and high drilling efficiency. The drill bit is used as a rock breaking tool in drilling operations. The improvement of drilling speed plays a decisive role, and its life and performance directly affect the quality, speed and comprehensive cost of drilling engineering

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