The oil casing pipe is a high-end product for steel pipe production. There are many types of casing, and there are a total of 15 types of casing diameter specifications. The outer diameter range is 114.3-508mm; the steel grade is divided into J55 pipe, K55 pipe, N80 pipe , L-80 , P-110, C-90, C-95, T-95 and other 11 kinds; casing pipe end buckle type and many types of requirements, can be processed button type STC, LC, BC, VAM and other buckle type.The oil casing production and installation process involves a lot of tests, mainly the following:
1. Ultrasonic testing
When the ultrasonic wave propagates in the material to be detected, the acoustic characteristics of the material and the changes in the internal structure have an influence on the propagation of the ultrasonic wave. Through the degree and condition of the ultrasonic wave to detect, to understand the change of the material properties and the structure.
2. Ray detection
Radiographic examination uses the difference in the amount of radiation transmitted between the normal site and the defect site, resulting in a difference in blackness on the substrate.
3. Penetration testing
Penetration testing is the use of the capillary action of the liquid, penetrating the permeate into the open defect on the surface of the solid material, and then drawing the penetrating permeate through the developer to the surface to reveal the presence of defects.Penetration testing is suitable for various metal and ceramic workpieces, and the time from infiltration operation to defect display is relatively short, generally about half an hour, surface fatigue, stress corrosion and welding cracks can be detected, and the crack size can be directly measured.
4. Magnetic particle testing
Magnetic particle detection uses magnetic flux leakage at the defect site to adsorb the magnetic powder and form magnetic marks to provide defect indications. The surface and subsurface defects can be detected. The nature of the defects is easy to identify. The paint and plating surface do not affect the detection sensitivity.
5. Eddy current testing
The eddy current test mainly uses the eddy current induced in the workpiece by the ferromagnetic coil to analyze the internal quality of the workpiece. It can detect the surface and near surface defects of various conductive materials. Usually the parameter control is difficult, the test result is difficult to interpret, and the test object is required. Must be a conductive crack and indirectly measure the length of the defect.
6. Magnetic flux leakage detection
The oil casing magnetic flux leakage detection is based on the high permeability property of the ferromagnetic material. The quality of the in-service oil casing can be detected by measuring the magnetic permeability change caused by defects in the ferromagnetic material.
7. Magnetic memory detection
Magnetic memory detection is a relationship between the physical nature of magnetic phenomena and metal dislocation processes. It has many advantages such as high efficiency, low cost, no need for grinding, and so on. It has important and wide application prospects in industry.
Among the several detection methods, there are no specific standards for magnetic memory testing of products, which are yet to be developed. The remaining six types have their own testing standards and are relatively mature.