What Does Critical buckling load Mean?
The critical buckling load can be defined as that load beyond which the compressive load in a tubing causes it to become unstable and deform.
Directional drilling is widely used to drill deviated wellbores that deflect from the vertical at an angle to access a formation. While drilling a deviated wellbore however, the drill string is likely to face some challenges such as pipe buckling and damage to casing due to applied load on the drill bit.
Buckling causes the pipe or tubing to lose some strength and mechanical properties because of excess weight or torque on the bit.
Trenchlesspedia Explains Critical buckling load
The buckling force normally occurs when the threshold force is less than the buckling thrust. Buckling can cause the deformation of the tubing into a sinusoidal or helical shape.
Sinusoidal buckling causes the tube to snap into a sinusoidal shape and is also called lateral buckling. Helical buckling causes the tube to snap into a helical or spiral shape.
The drill string buckling problem of a directional borehole has many parameters, but the principle feature is associated with the variability of the internal compressive axial force. The zone where the drill string will buckle is not known and the stability analysis is performed for the entire length of the drill string.