Oil casing pipe is an important part of oil drilling. It plays key roles in supporting the well wall, preventing well wall collapse, and controlling bottom well pressure. Therefore, quality inspection of oil casing is crucial to ensure the safety and smooth progress of drilling operations.
The quality testing methods of oil casing mainly include the following aspects:
1. Appearance inspection
Appearance inspection is one of the most basic quality inspection methods. By carefully observing the appearance of the oil casing, you can check whether there are cracks, deformations, corrosion and other problems. At the same time, it is also necessary to check whether the welds of the casing are complete and whether there are welding defects.
2. Size measurement
Dimensional measurement is an important part of oil casing quality inspection. By using measuring tools, such as calipers, vernier calipers, etc., measure the diameter, wall thickness and other dimensions of the casing to ensure that it meets the design requirements.
3. Material testing
Material testing of oil casing is one of the key steps to ensure its quality. Commonly used material testing methods include chemical composition analysis, metallographic structure analysis, hardness testing, etc. These testing methods can check whether the composition of the casing material meets the standard requirements and whether its organizational structure is uniform and dense.
4. Pressure detection
Oil casing needs to withstand high pressure during drilling operations, so pressure testing is one of the essential quality inspection methods. By installing the casing on special testing equipment, applying a certain amount of pressure, and observing whether there are leaks, deformations, etc., the casing is ensured that it can withstand the expected working pressure.
5. Magnetic particle testing
Magnetic particle testing is a commonly used non-destructive testing method used to detect cracks, defects and other problems on the surface of casing and welds. By coating magnetic powder on the surface of the casing and then applying a magnetic field, the accumulation of magnetic powder at cracks or defects can be observed to determine whether there is a problem with the casing.
6. Penetration testing
Penetrant testing uses the capillary action of liquid to penetrate the penetrating liquid into the open defects on the surface of the solid raw material, and then uses the imaging agent to suck the penetrating liquid out to the surface to reveal the presence of defects. Penetration testing is suitable for various metal and ceramic workpieces, and the time from penetration operation to defect manifestation is relatively short, usually about half an hour. It can detect surface fatigue, stress corrosion and welding cracks, and can directly measure the size of cracks.
7. Ray detection
Radiographic detection uses the difference in the amount of radiation transmitted through normal parts and defective parts to determine the blackness on the film.
8. Ultrasonic testing
When ultrasonic waves spread in the material being tested, the changes in the acoustic properties and internal structure of the material have a certain impact on the spread of ultrasonic waves. By detecting the degree and situation of the impact of ultrasonic waves, we can understand the changes in the function and structure of the material.
In short, the quality inspection of oil casing is an important link to ensure the safety and smooth progress of drilling operations. Through methods such as appearance inspection, dimensional measurement, material testing, pressure testing, magnetic particle testing, penetrant testing, radiographic testing, and ultrasonic testing, the quality status of the casing can be comprehensively and accurately evaluated, and problems can be discovered and solved in a timely manner. Ensure the smooth progress of oil drilling operations.
