Numerical Simulation and Analysis of Magnetic Detection in Oil and Gas Casings

Metal oil and gas casings undergo magnetization phenomena when influenced by the geomagnetic field, subsequently affecting the surrounding magnetic field. By utilizing COMSOL Multiphysics software, the distribution pattern of magnetic anomalies around casing with couplings under the influence of the geomagnetic field can be simulated and analyzed. The research results indicate that the direction of the magnetic field generated by casing magnetization is correlated with the direction of the geomagnetic field. Additionally, the magnetic field surrounding the magnetized casing exhibits significant fluctuations at a distance of approximately 5 meters from the casing. Analyzing these fluctuations can help identify abnormal conditions such as casing damage. These research findings provide theoretical assistance for understanding the distribution pattern of the magnetic field around magnetized casings and contribute to practical drilling casing applications.