Petroleum casing can be roughly divided into: 1. surface casing; 2. intermediate casing; 3. production casing; 4. drilling casing.
The surface casing is mainly used to suspend and support the subsequent layers of casing through the casing head installed on the top. The other is to isolate the shallow surface water layer from the front complex formation to protect the drilling well from the pollution of the shallow water layer.
Intermediate casing, or technical casing, is used to isolate layers with different formation pressures or complex formations that are prone to collapse and leak water.
The production casing is used to protect the production zone, as well as the channel provided to transport oil and gas from the production zone to the surface.
The drilling liner is used to reduce the rig load and post-casing load during and after cementing, saving casing and cement, and reducing the cost of cementing. In the use of industries and fields, oil casing has shown an important role and good performance.
The anti-corrosion of petroleum casing pipe is mainly divided into: 1. Anti-corrosion coating is painted on the outer wall. 2. Brush the anti-corrosion coating on the inner wall. 3. Apply anti-corrosion and cooling coating. With the use of this oil casing in the harsh oil extraction industry such as polar regions and oceans. As far as the material and structure of the petroleum casing are required, it must have good joints, excellent physical properties, stable chemical properties, and a wide temperature range. If the oil casing cannot be made, it should be coated with anti-corrosion coating. Come and help him cope with the harsh environment. The coating on the outer wall is used to reduce external erosion. The anti-corrosion coating on the inner wall is to reduce friction, reduce corrosion in the pipe, and increase oil delivery. The anti-corrosion and thermal insulation coating is to transport crude oil and fuel oil and reduce the heat radiated by the pipeline to the soil.https://www.permanentsteel.com/productshow/casing-pipe.html