Vibration damper

VIBRATION DAMPER (EN: vibration damper; DE: Vibrationsloscher; FR: amortisseur de vibration; ES: amortiguador de vibraciones; RU: виброгаситель) is the device, which is decreasing the magnitude and amplitude of the mechanical oscillations of the drill string, and of the hydraulic impulses of the pressure of the liquid inside the pipes, during the drilling of the boreholes. The vibration damper is used in case of the rotary drilling with the usage of the bottomhole motors (turbine borer, electric borer, hydraulic striker, pneumatic striker), or with the rotation using the rotor of the drill string.

The vibration damper decreases the influence of the vibration onto the drilling tool, bottomhole motor, superficial equipment, and servicing personnel, and improves the indicators of the drilling. For the decreasing of the mechanical oscillations of the drill string, they use as the vibration damper the shock absorbers, dampers, and the bottomhole mechanisms for the advancement of the drill bit (RU: ЗМП, забойные механизмы подачи долота). They use within the shock absorbers the elastic elements (springs, rubber, and so on), during the deformation of which there proceeds the decreasing of the mechanical and torsional oscillations of the pipes. Within the bottomhole mechanisms for the advancement of the drill bit, the difference of the pressure acts onto the piston, which moves down during the drilling of the bottomhole, thus ensuring the constant loading onto the drill bit, and absorbs the oscillations of the lower part of the drill string. As the vibration damper against the hydraulic impulses of the pressure, they use: the widening places of the pipeline; the spring-loaded pistons; the chambers with the compressed air or gas, which are separated from the flow of the liquid using the elastic diaphragm; the rigid reflectors, which are made in the form of the partitions with the holes for the interference of the waves; the throttles, and so on.

For the decreasing of the mechanical oscillations and pressure of the liquid, in case of all the methods for the drilling, there may be used the combined device, within which the spring-loaded piston is installed onto the movable spindle, which is connected with the lower part of the drill string.