Types of Octg Casing And Their Applications

1. Conductor Casing: This is the outermost casing that is installed during the initial drilling phase. It protects the wellbore from collapsing and acts as a conduit for drilling fluids.

2. Surface Casing: This casing is set below the water table or any unstable formations near the surface. It isolates the wellbore from shallow groundwater and prevents contamination.

3. Intermediate Casing: This casing is installed to protect the wellbore and isolate certain zones during drilling or completion operations. It provides additional strength to the well structure, particularly in areas with unstable formations.

4. Production Casing: This is the final casing that is run into the well after drilling is complete. It is specifically designed to withstand high pressures and temperatures during production operations. It provides structural integrity to the well and prevents fluid migration.

5. Liner: A liner is a smaller diameter casing that is installed inside the existing production casing. It is used to extend the wellbore beyond damaged or depleted zones to reach new production zones.

6. Expandable Casing: This casing can be expanded radially to fit a larger wellbore diameter, providing a cost-effective alternative to drilling a new well. It is commonly used in wellbore rehabilitation or in wells with irregular diameters.

Each type of casing has specific applications based on the well conditions, drilling operations, and production requirements. The selection of casing depends on factors such as well depth, pressure, temperature, and reservoir characteristics.