The basic role of casing pipe
1. Strengthening the well wall: As a compaction structure, casing pipe mainly plays the role of strengthening the well wall. The setting of casing pipe can effectively prevent the collapse of the well wall and maintain the integrity and stability of the well wall.
2. Preventing wellhead collapse: After drilling the well, the wellhead changes continuously due to formation changes, subsidence and other reasons. If the casing pipe is not reinforced in time, the wellhead is easy to collapse, resulting in interruption of downhole operation.
3. Ensure the safety and smooth progress of downhole operations: The setting of casing pipe can effectively reduce the impact of ground dynamic factors on downhole operations and ensure the safety and smooth progress of downhole operations.

Classification of casing pipe
At present, according to the purpose and nature of casing pipe, casing pipe can be divided into production casing pipe, isolation casing pipe, cementing casing pipe and steel casing pipe.
1. Production casing pipe: Production casing pipe refers to the casing pipe used directly in the process of oil and gas production. Its main function is to guide the smooth rise of production fluid.
2. Isolation casing pipe: Isolation casing pipe refers to casing pipe used to prevent abnormal conditions in the well, such as explosion prevention and protrusion prevention.
3. Cementing casing pipe: Cementing casing pipe is a casing pipe added after drilling or completion. Its main function is to seal the wellbore, prevent oil and gas from leaking around the wellbore, and maintain the air pressure in the well.
4. Steel casing pipe: Steel casing pipe refers to a structure similar to a building staircase, that is, multiple pipes are put together to prevent bending and deformation.

Precautions for casing pipe installation
1. The casing pipe should be fully cleaned, inspected and pressure tested before installation in the well, and the prescribed operating procedures should be strictly followed.
2. The strength of the casing pipe must meet the requirements of on-site operations, and there should be no residues, protrusions, grooves, etc. during the installation process.
3. The lower part of the casing pipe should be equipped with a joint to ensure that the line is close and leak-free. The remaining parts should be fixed in a professional way to ensure that they are firmly fixed.

Summary
Casing pipe is an important part of drilling operations, and its importance cannot be underestimated. It can not only strengthen the well wall and prevent the occurrence of well wall collapse and wellhead collapse accidents, but also ensure the safety and smooth progress of underground operations. In order to ensure the safety and smoothness of underground operations, the selection, installation and maintenance of casing pipe must be strictly carried out in accordance with the prescribed operating procedures.