Method for realizing oil-gas detection by applying long-offset distance transient electromagnetic array method

Abstract

The invention relates to a method for realizing oil-gas detection by applying a long-offset distance transient electromagnetic array method. The method comprises the following steps: firstly, carrying out ATEM (analytical transmission electron microscopy) observation on a detection region to acquire data; selecting measuring points without obvious distortion or negative anomaly of electric field components while an induced polarization field is not stripped, utilizing the ATEM data for inversion, and acquiring a high-resolution lamellar specific resistance model in a detection region; then carrying out ATEM forward operation to obtain transient induced electric field or magnetic field attenuation curves of all the measuring points in the detection region; substracting the electric field or magnetic field component attenuation curve acquired during forward operation by the actually observed ATEM electric field or magnetic field component attenuation curve at the same observation time point to obtain a time domain induced polarization spectrum; applying a time domain induced polarization method for inversion to obtain the polarizability of an underground medium; and carrying out detection and evaluation on an oil-gas reservoir by utilizing the specific resistance and polarizability parameters. According to the invention, the accuracy and reliability of exploration on the oil-gasreservoir by utilizing an electromagnetic method are greatly enhanced, the working efficiency is improved, and the exploration cost is lowered.

Description

technical field [0001] The invention relates to a method for obtaining time-domain IP spectrum from long-offset transient electromagnetic array method (ATEM) observation data and then detecting oil and gas. Background technique [0002] In oil and gas geological exploration, whether the electromagnetic method is based on the resistivity parameter or the IP method is based on the polarizability parameter, the observed electromagnetic field signals include DC field, induction field and excited polarization field. Obviously, the excited polarization field in the electromagnetic method is an interference field, and the induction field in the induced electricity method is an interference field. How to separate the induced field and the excited polarization field is an important guarantee to improve the interpretation accuracy of the method. [0003] At the end of the last century, the complex resistivity method (CR) developed in the IP measurement mainly observes the induced ele...

AI Technical Summary

Problems solved by technology

There are two reasons: one is that the electromagnetic method works at a higher frequency, and the model assumptions still have theoretical flaws; the other is that the non-uniqueness of the solution is caused by nonlinear problems in the forward and inversion process

However, for the ATEM method, since it works in the time domain and only measures the secondary field, the observation time is long after the power is turned off, so it is easy to extract the induced electric spectrum

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