Casing shoe in drilling is the process of drilling out the specialized components at the bottom of the cemented casing string to continue drilling the wellbore. The casing shoe assembly typically includes a guide shoe (or float shoe) and a float collar, along with a cement plug inside the casing above these components. Once the cement around the casing has set, a drilling assembly, usually with a drill bit, is run inside the casing to drill through the cement plug and then out through the casing shoe. The materials used in the casing shoe are designed to be drillable, allowing the bit to penetrate them relatively easily. This step is essential to establish communication with the formation below the casing and to deepen the well to the next planned section. Drilling the casing shoe confirms the integrity of the cement job at the bottom of the casing and allows for continued drilling operations into virgin formations.
