What is the Ladder Buckle Oil Casing Pipe

Because the shape of yoke buckled oil casing is like ladder, it is called stepped oil casing, which is one of the commonly used buckled shapes of oil casing.
Ladder oil casing is called BTC ladder oil casing for short. It is mainly used to support the well wall during and after drilling to ensure the normal operation of the whole well during and after drilling. The casing of the casing with offset thread is bound with steel wire or steel strip.


According to different well conditions and different geological conditions, different grades of stepped casing are selected. It is also required that the shell itself has corrosion resistance in corrosive environment. The calculation formula of weight is: [((outer diameter - wall thickness) * wall thickness] * 0.02466 = kg / M (weight per meter). The main materials include J55, K55, N80, L80, C90, T95, P110, q125, V150. The advantages of trapezoidal thread profile increase the resistance to axial and axial compression loads and provide leakage resistance.