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Factors Affecting The Use Of Drill Pipe

Update:31-07-2020
Abstract:  Although the drill pipe is designed to be used under various drilling conditions, the following factors have a great i...

  Although the drill pipe is designed to be used under various drilling conditions, the following factors have a great influence on the normal operation of the drill pipe.

  1. Drilling fluid

  The drill pipe can be adapted to various types of drilling fluid, but the specific gravity and viscosity of the drilling fluid should be considered. On the premise of satisfying well washing, the specific gravity and viscosity of drilling fluid should be reduced as much as possible. The specific gravity of the drilling fluid should not be greater than 1.50.

  2. Drilling weight

  During the drilling process, the pressure of the drill should be gradually increased to make the pressure drop of the drill pipe motor reach the upper limit of the specified value as much as possible to ensure that the maximum output torque of the drill pipe motor meets the requirements. The drill bit needs to break the rock. At the same time, the drilling weight should be controlled within the recommended maximum drilling weight. Excessive drilling pressure will not only damage the thrust bearing of the driveshaft but also cause excessive pressure drop of the motor and cause stagnation. If the dead time is too long, the motor will be seriously damaged.

  3. Torque

  The characteristic of the drill pipe is that the output torque is proportional to the voltage drop of the motor. The actual output torque of the drill pipe during operation depends on the weight of the drill bit. Theoretically, the torque change does not affect the working speed. The motor with better performance is reduced from no-load to the effective maximum working load area, and the speed reduction does not exceed 10%. The drill pipe drives the drill bit to rotate clockwise, and at the same time generates a reverse torque on the drill bit housing. The magnitude of the reverse torque is the sum of the output torque and the friction loss torque. The reverse torque is transmitted to the drill string through the drill pipe shell, resulting in a tight connection between the upper part of the drill pipe motor and the buckle, and the lower part of the drill pipe motor is connected to the convex belt Buckle, when the drilling tool stagnates, the reaction torque reaches the maximum value. Since the reaction torque will affect the azimuth of the borehole, it is necessary to consider the existence of the reaction torque in the orientation operation.