Typically run above weak formations, requiring protection from the pressure, generated by the cement column. Normally installed on the casing string above the weak formation, its design allows cement to flow in an upward direction, yet help to prevent it from falling downward.
- Constructed of thin steel petals, arranged in an overlapping pattern and reinforced by string steel ribs.
- Also used in stage cementing or in cementing the annulus from surface.
- Easy installation by sliding over the pin end of a casing joint, prior to make-up.
- Can be used in place of an external casing packer for stage cementing application.
- Each overlapping petal provides maximum flexibility and fluid passage while maintaining optimum support characteristics.
- Allows for casing rotation and reciprocation.