Drill collar use: one of the most important parts of the drill string, it has the function of providing drilling pressure to the drill bit and improving the rigidity of the drill string.
Based on the analysis of the working environment and stress of oil drill pipes, the main failure modes of drill pipes include fracture, plastic deformation (such as bending), and serious wear of the thread. Among them, fracture is the most serious form of failure. This failure form is manifested in that when the shoulder of the drill rod head bears a large torsion and impact force, the drill rod will break there.
When drilling, its role is not only to transmit torque and form a channel for circulating flushing fluid; at the same time, through the relative movement between the inner and outer pipes, the lower drilling tool can be protected from the heave of the floating drilling device and perform normal operations. Drill into work. However, because the inner and outer pipes move relative to each other, the upper drilling tool also rises and falls.
With a drill bit, there must be its "brother" drill pipe. What a drill pipe is, we can easily understand l