Patent ID: 11959879
Assignee: SOUTHWEST PETROLEUM UNIVERSITY
Field: Measurement (Instruments)
Classification: CPC G | IPC G

Claim 0:
1. A method for determining characteristics of metallic casing and casing attenuation, comprising the following steps:
obtaining the ratio of first magnetic field intensities around a solenoid with a metallic casing and without the metallic casing at DC mode;
obtaining magnetic related parameter of the metallic casing through the ratio of the first magnetic field, specifically:
obtaining the relationship between the first magnetic field ratio and α/μ0 by simulation;

obtaining the magnetic related parameter of the metallic casing through the first magnetic field ratio and μ0, where α is the magnetic related parameter and μ0 is the magnetic permeability in free space;
obtaining magnetic permeability of metallic casing through the magnetic related parameter of the metallic casing;
obtaining the ratio of second magnetic field intensities around a solenoid with the metallic casing and without the metallic casing at AC mode;
obtaining electrical related parameter of the metallic casing through the ratio of the second magnetic field and the magnetic related parameter of the metallic casing;
obtaining electrical conductivity of metallic casing through the electrical related parameter of metallic casing, specifically:
obtaining the relationship between the second magnetic field ratio, the magnetic related parameter of the metallic casing, and the electrical related parameter of the metallic casing by simulation, and obtaining the electrical related parameter of the metallic casing by combining the ratio of second magnetic field and the magnetic related parameter of the metallic casing;

obtaining casing attenuation of metallic casing through the magnetic related parameter and the electrical related parameter of metallic casing.