Oil casing pipe is considered a premium product in the steel pipe industry, with a wide variety of specifications. There are 15 different outer diameter sizes, ranging from 114.3mm to 508mm. The steel grades are categorized into 11 types, including J55, K55, N80, L-80, P-110, C-90, C-95, and T-95. Various end connection types are available for oil casing pipes, such as STC, LC, BC, and VAM. The production and installation process of oil casing pipes involves a series of rigorous tests, which include the following.
Ultrasonic Testing
Ultrasonic testing involves the propagation of ultrasonic waves through the material. The material’s acoustic characteristics and internal structural changes affect the wave propagation, allowing inspectors to detect material property changes and structural flaws based on the behavior of the waves.
Radiographic Testing
Radiographic testing uses differences in radiation transmission between normal areas and defect areas. This difference is captured as variations in blackness on a radiographic film, allowing the detection of internal defects.
Penetrant Testing
Penetrant testing uses liquid capillary action to detect surface defects. The penetrant seeps into surface cracks or defects, and after a developer is applied, the defects become visible. This method is suitable for metal and ceramic workpieces and is effective in detecting surface fatigue, stress corrosion, and welding cracks.
Magnetic Particle Testing
Magnetic particle testing detects surface and near-surface defects by using magnetic flux leakage. The magnetic particles accumulate at the defect site, forming visible indications. This method is effective even on painted or plated surfaces without significantly affecting sensitivity.
Eddy Current Testing
Eddy current testing uses an electromagnetic coil to induce eddy currents in the material, which can reveal surface and near-surface defects in conductive materials. Although it provides valuable information, interpreting the results can be challenging, and the material must be conductive to generate useful data.
Magnetic Flux Leakage Testing
Magnetic flux leakage testing is based on the high permeability of ferromagnetic materials. Defects in the material cause changes in magnetic permeability, which are measured to evaluate the quality of the casing pipe in use.
Magnetic Memory Testing
Magnetic memory testing involves analyzing the relationship between magnetic phenomena and metal dislocation processes. It offers several advantages, such as high efficiency, low cost, and the absence of surface preparation, making it a promising method for industrial applications.
While magnetic memory testing is still in development with no standardized guidelines, the other six testing methods are well-established, each with its own set of testing standards.
