The drill is the general name for the downhole tool. Including kelly, drill pipe, weighted drill pipe, drill collar, non-magnetic drill collar, adapter, drill string stabilizer, etc. The string of tubes that link these downhole tools is called a drill string.
The drill string is a hub that connects the ground to the ground. During the drilling process, the transmission of ground power and the transportation of drilling fluid are realized by the drill string; the changes of the formation and the complicated conditions of the underground can also be reflected to the ground through the drill string; in addition, other operations in the drilling process, such as coring The handling of downhole accidents, midway tests, etc. must be achieved by relying on the drill string. Once an accident occurs in the drill string, it will bring some economic losses. Therefore, good management and use of drilling tools are particularly important in the drilling process.