Fast numerical simulation method for two-dimensional magnetotelluric field

Abstract

The invention provides a fast numerical simulation method for a two-dimensional magnetotelluric field, which combines a finite element method with Fourier transform, transforms a two-dimensional partial differential problem into a mutually independent one-dimensional ordinary differential problem among different wave numbers by performing Fourier transform along the horizontal direction, is high in parallelism degree, effectively reduces the calculation amount, and improves the calculation efficiency. The calculation efficiency is improved; conditions are provided for refined numerical simulation of the magnetotelluric method under a large-scale condition; through verification, a result calculated by adopting the method disclosed by the invention is within an error rod range of international public data recorded in the Zhdanov et al.1997 literature, is close to a mean value, and meets a precision requirement.

Description

technical field [0001] The invention relates to the technical field of geophysical methods, in particular to a fast numerical simulation method of a two-dimensional magnetotelluric field. Background technique [0002] The magnetotelluric method is a frequency-domain electromagnetic prospecting method, which uses the natural electromagnetic field of vertical incidence in the high altitude (the frequency band is 10 -4 -10 4 Hz) to realize the detection of underground geological structures and abnormal bodies, which has the advantages of simple operation, high work efficiency, low cost, and large detection depth. At present, this method has been widely used in geological exploration, metal ore and oil and gas resource exploration, geodynamics research and other fields, and has achieved more and more obvious economic and social benefits. However, the successful implementation of this method depends on the forward and inverse interpretation of the subsurface geological model. ...

AI Technical Summary

Problems solved by technology

Integral equation method faces huge challenges when calculating large-scale anomaly models; finite element method grid division and coefficient matrix formation are relatively time-consuming, which limits its application in large-scale electromagnetic exploration; finite difference method uses Structured grids, it is difficult to deal with undulating terrain and complex anomalies

Moreover, with the increase of the calculation scale of these numerical simulation methods, the calculation time and calculation memory increase nonlinearly, which greatly limits the forward and inverse interpretation of large-scale magnetotelluric exploration.

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