System and method for obtaining and analyzing flux leakage data in the inspection of oil and gas wells
Embodiments of the present disclosure are directed towards a method for obtaining and analyzing flux leakage data. Embodiments may include measuring, using a magnetic flux leakage tool, magnetic flux leakage data from a casing and determining sensor liftoff data from the flux leakage data. Embodiments may also include performing outward analytic continuation of the magnetic flux leakage data from a sensor plane to one or more additional planes and extrapolating back from the one or more additional planes to a surface. Embodiments may include applying a model-based parametric inversion to the magnetic field flux leakage data and determining, based upon, at least in part, the model-based parametric inversion, a shape and size of a corresponding corroded area associated with the casing.
1. A method of improving flux leakage data to remove a sensor liftoff effect comprising:
measuring, using a magnetic flux leakage tool, magnetic flux leakage data from a casing;
determining sensor liftoff data from the magnetic flux leakage data;
performing outward analytic continuation of the magnetic flux leakage data from a sensor plane to one or more additional planes; and
extrapolating back from the one or more additional planes to a surface; wherein extrapolating back includes a linear extrapolation approach.
2. The method of claim 1 , wherein extrapolating back includes a polynomial extrapolation approach.
3. The method of claim 1 , further comprising:
determining a magnetic field distribution at zero liftoff.
4. The method of claim 1 , further comprising:
integrating a normal component of a magnetic field to determine a shape of a defect.
5. The method of claim 4 , further comprising:
displaying the shape of the defect for interpretation.
6. The method of claim 1 , further comprising:
applying a deconvolution inversion filter to the magnetic flux leakage data.
7. A system for correcting magnetic flux leakage data to remove a sensor liftoff effect comprising:
a magnetic flux leakage tool including a sensor and at least one processor configured to:
measure, using the magnetic flux leakage tool, magnetic flux leakage data from a casing;
determine sensor liftoff data from the magnetic flux leakage data;
perform outward analytic continuation of the magnetic flux leakage data and the sensor liftoff data from a sensor plane to one or more additional planes; and
extrapolate back from the one or more additional planes to a surface; wherein extrapolating back includes a linear extrapolation approach.
8. The system of claim 7 , wherein extrapolating back includes a polynomial extrapolation approach.
9. The system of claim 7 , further comprising:
determining a magnetic field distribution at zero liftoff.
10. The system of claim 7 , further comprising:
integrating a normal component of a magnetic field to determine a shape of a defect.
11. The system of claim 10 , further comprising:
displaying the shape of the defect for interpretation.
12. The system of claim 7 , further comprising:
applying a deconvolution inversion filter to the magnetic flux leakage data.