In the oil and gas industry, casing pipes are an essential part of various underground construction. Casing pipes are used for:
- Providing a stronger foundation for a dipper drill
- Sealing high-pressure zone surfaces to avoid getting blown off
- Enabling smooth bore for installing equipment
- Preventing contamination of surrounding water
But there are five different types of casing pipes to consider when planning for each well.
Different Types of Casing Pipes
Holes are started with a small auger drill. The conductor casing is the first casing installed to:
- Prevent the soil from caving in
- Aid in the circulation of the drilling fluid
It’s vital that the conductor casing, usually between 16 and 42 inches in diameter, be cemented into place before any drilling is performed.
Surface casing is installed by fitting into the conductor casing. This type of casing is used to prevent the contamination of the water deposits found near the surface. It also protects the drill hole from being affected by the drilling process.
When drilling is done, the deeper you get, the more likely you will encounter sections of:
- Low pressure
- Unstable soil
- Formations that can contaminate the well
The intermediate casing protects the well from any of those hazards.
The last casing section, also known as ‘oil string,’ is the production casing. The production casing will serve as the conduit from the surface to the petroleum. This section needs to be cemented correctly since it’s in the deepest part of the hole.
Liner String Casing
Liner string casings aren’t always used in wells. When they are, they are attached by ‘hangers,’ making it a less permanent casing.