Fluid saturation inversion method and device

Abstract

The invention provides a fluid saturation inversion method and device, and relates to the technical field of geophysics, and the method comprises the steps: obtaining electromagnetic field parameters based on a space rectangular coordinate system; generating resistivity tensor data by using the electromagnetic field parameters; using the resistivity tensor data to determine a target parameter value in an Achie formula; and generating a fluid saturation inversion result by using the target parameter value and an azig formula. According to the method, the target parameter value in the Azig formula is corrected by calculating the resistivity tensor data, and the prediction precision of the fluid saturation is improved.

Description

technical field [0001] The invention relates to the technical field of geophysics, in particular to a fluid saturation inversion method and device. Background technique [0002] In the electromagnetic wave detection process for shale oil and gas, the electrical properties of shale have obvious anisotropy. Anisotropy refers to the fact that the electrical parameters of shale show different values ​​in different directions, which are mainly reflected in the resistivity and permittivity of shale. In anisotropic media (for example, media with large cracks), with the change of crack shape, the equivalent electrical parameters will change greatly, while the resistivity in Archie's Law (Archie's formula) is a scalar, which cannot characterize each Anisotropy, which leads to a large error in the estimated water saturation. In classical electromagnetic theory, the constitutive forms of conductivity and resistivity are both second-order tensors, each of which contains nine component...

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Problems solved by technology

In anisotropic media (for example, media with large cracks), the equivalent electrical parameters will change greatly with the change of crack shape, while the resistivity in Archie's Law (Archie's formula) is a scalar value, which cannot characterize each anisotropy, which leads to large errors in the calculated water saturation

In the classical electromagnetic theory, the constitutive forms of conductivity and resistivity are both second-order tensors, each of which contains nine components in different directions. For an anisotropic medium, the change information of its electrical parameters is reflected in this In the expression of the nine components, if only the scalar conductivity or resistivity is used to describe, the information on the components in other directions will be lost, making the inversion effect of physical parameters such as water saturation unsatisfactory

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