Casing pipe is a kind of large diameter pipes and it has fixed the role for the oil and gas casing or hole. The casing pipe is inserted into the hole and fixed with cement, in order to prevent the borehole and separated strata borehole collapse, and ensure the drilling mud circulating flow.

In oil production process using different types of casing:

Surface casing

Provide blowout protection, isolate water sands, and prevent lost circulation;

Support the wellhead equipment and keep the other layer weight of the casing.

Intermediate casing

Separation the pressure for different levels, in order to the drilling fluid lines normal circulation and protect the production casing;

In order to complete installation reverse blowout device, drilling blowout preventer and the tail pipe.

Production casing

Oil and natural gas are derived from the storage layer under the surface of the earth;

Used to protect the drilling, drilling mud layer.