Numerical Studies on Current Injection Methods of 3D Field Distribution of the Discontinuous Blowout Well

At present, the relief well is the most effective method to control blowout accidents where the accurate detection of the relative position between the relief well and the blowout well is the key to accurately imply the rescue operations. In the numerous methods, current injection method plays an irreplaceable role in blowout well detection. In this paper, a three-dimensional (3D) model of the discontinuous blowout well casing, a common scenario during well detection, is built and simulated with Finite Element Method (FEM). Both current flow and the corresponding magnetic field distribution are obtained. Moreover, the impact of the length of the fracture on the blowout well casing on the magnetic field magnitude is discussed. The results show that the longest fracture that can be detected by the magnetometer with a sensitivity of 2nT is 150m. The discontinuous model of blowout well casing proposed in this paper is of great theoretical value and lays a foundation for the research of the drilling work.