How to classify and protect oil casing

First, what are the classifications of oil casing?

Oil casing can be broadly classified according to its application into surface casing, intermediate casing, production casing, and drilling casing.

(1) Surface Casing: Surface casing uses a casing head installed at the top to suspend and support subsequent casing layers. It also isolates shallow surface water layers from complex formations ahead, protecting the well from contamination by shallow water.

(2) Intermediate Casing, or technical casing: This is used to isolate formations with different pressures or complex formations prone to collapse and leakage.

(3) Production Casing: Production casing protects the production layer and provides a channel for transporting oil and gas from the production layer to the surface.

(4) Drilling Liner: Drilling liners reduce the load on the drilling rig and the casing itself during and after casing installation and cementing, saving on casing and cement, and reducing cementing costs. In various industries and fields, oil casing has demonstrated important roles and excellent performance.

Second, how is corrosion protection for oil casing carried out?

Corrosion protection for oil casing mainly involves: 1. Applying an anti-corrosion coating to the outer wall of the oil casing. 2. Applying an anti-corrosion coating to the inner wall of the oil casing. 3. Applying an anti-corrosion and cooling coating.

With the increasing use of oil casing in harsh environments such as polar regions and oceans, the materials and structure of the oil casing must possess excellent joint properties, superior physical properties, stable chemical properties, and a wide temperature adaptability range. If the oil casing cannot meet these requirements, an anti-corrosion coating should be applied to help it cope with the harsh operating environment. Applying a coating to the outer wall of the oil casing reduces external corrosion. The anti-corrosion coating on the inner wall of the oil casing reduces friction, lowers internal corrosion, and increases oil throughput. The anti-corrosion and heat-insulating coating reduces heat loss from the oil casing to the soil when transporting crude oil and fuel oil.