Method for computing electromagnetic response error caused by emission source attitude change

Abstract

The invention provides a method for computing the electromagnetic response error caused by emission source attitude change. According to the method, an emission source of any attitude is converted into an equivalent electric dipole source in a corresponding computing coordinate system through Euler rotation and matrix transformation; Fourier transformation is conducted on structural trend, a full-three-dimensional electromagnetic problem is transformed into a two-dimensional problem, and a wavenumber domain electromagnetic field equation suitable for electric dipoles in any direction is derived; the equation is solved within the y-z plane through a finite element method, and a spatial domain ocean electromagnetic response is obtained through Fourier inverse transformation; finally the ocean electromagnetic response error caused by emission source attitude deflection is computed. The method for computing the electromagnetic response error caused by emission source attitude change is provided for the situation that the emission source attitude changes under the action of underflow in the ocean controllable source electromagnetic surveying process, and guidance for analyzing and correcting the data error caused by emission source attitude change in the actual ocean controllable source electromagnetic observation process is provided so as to improve the accuracy of ocean controllable source electromagnetic surveying process.

Description

technical field [0001] The invention belongs to the field of geophysical surveying, in particular to the field of marine controllable source electromagnetic exploration, and relates to a calculation method for controllable source marine electromagnetic response errors caused by attitude changes of emission sources. Background technique [0002] The marine controlled source electromagnetic method has the characteristics of being able to distinguish the properties of oil and water in deep-water traps and revealing "high-resistivity bodies" covered by volcanic rocks. It has played an important role in reducing the risk of deep-water oil and gas exploration and reducing multiple solutions. It is an important means for the country to carry out deep water oil and gas exploration. At present, both academic research and actual data processing are mostly based on the assumption of a horizontal emitting dipole on the seabed. The actual deep-water marine environment is complex and cha...

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Problems solved by technology

But the article is still limited to the study of the one-dimensional layered model

The attitude of the emission source changes in three-dimensional space, and the geological structure of the seabed and the conductivity of the formation have complex spatial variation characteristics. It is often difficult to effectively describe the anomaly of the electromagnetic field with one-dimensional simulation

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