What are the common inspection methods for oilfield casing in energy projects

Oil casing is a high-end product manufactured from steel pipes. There is a wide variety of oil casing, with various types and requirements for pipe end couplings. Processable coupling types include STC, LC, BC, and VAM. The production and installation process of oil casing involves many inspections, mainly the following:

1. Ultrasonic Testing: When ultrasound travels through the tested material, the acoustic properties and internal structure of the material affect the transmission of ultrasound. By examining the degree and condition of this impact, changes in material properties and structure can be understood.

2. Radiographic Testing: Radiographic testing utilizes the difference in the amount of radiation transmitted between normal areas and defects, resulting in differences in the density of the film.

3. Impregnation Testing: Impregnation testing uses the capillary effect of a liquid. Impregnating liquid is introduced into the surface of a solid material at an open defect. A developer then draws the impregnating liquid back to the surface, revealing the presence of the defect.

4. Magnetic Particle Inspection: Magnetic particle inspection utilizes the magnetic flux leakage at defects to attract magnetic particles, forming magnetic traces that reveal the defects. It can detect both surface and subsurface defects, and the nature of the defects is easily identifiable.

5. Eddy Current Inspection: Eddy current inspection primarily uses eddy currents induced in a workpiece by a ferromagnetic coil to analyze the internal quality of the workpiece. It can detect surface and near-surface defects in various conductive materials, although parameter control is typically difficult.

6. Magnetic Flux Leakage Inspection: Oil casing magnetic flux leakage inspection is based on the high permeability of ferromagnetic materials. It measures the permeability caused by defects in the ferromagnetic material to assess the quality of in-service oil casing.

7. Magnetic Memory Detection: Magnetic memory detection originates from the relationship between the physical nature of magnetic phenomena in metals and dislocation processes. It has many advantages, including high efficiency, low cost, and no need for polishing, and has significant application prospects in industry.