Method for building seismic inversion low-frequency models

Abstract

The invention provides a method for building seismic inversion low-frequency models. The method comprises the following steps: collecting seismic data subjected to amplitude preserved processing and corresponding logging data in a seismic work area; carrying out well-to-seismic calibration for the logging data according to the known apriori geologic horizon and well drilling horizon; carrying out interpolation for the logging data subjected to well-to-seismic calibration, and thus establishing an initial model with wave impedance; optimizing the initial model according to the seismic data, and thus obtaining optimized wave impedance; carrying out high-frequency filtering for the optimized wave impedance, and thus obtaining high-frequency inversion results; changing the initial model in a trend-driven manner, and thus obtaining a change model; obtaining a new model according to the change model and the high-frequency inversion results; optimizing the new model according to the seismic data, and thus obtaining the optimal wave impedance; determining the seismic inversion low-frequency model according to the optimal wave impedance and the high-frequency inversion results. The method solves the problem that the inversion results have difficulty in quantification due to absence of low frequency of the seismic data, and the inversion precision is greatly improved.

Description

technical field [0001] The present invention relates to the technical field of geophysical exploration, in particular to the construction technology of seismic models, and specifically to a construction method of seismic inversion low-frequency models. Background technique [0002] Seismic exploration is to excite an artificial seismic source on the surface, and the vibration caused by the seismic source propagates underground in the form of seismic waves, and under certain conditions, it is reflected upwards and sent back to the surface, and then the reflected seismic waves are recorded by the geophone to obtain a seismic record (also called seismic data). Seismic records are obtained through the underground medium, which must be affected by the physical properties of the underground medium (such as lithology, density, porosity, etc.), which include not only reflected waves, but also noise, direct waves, surface waves, etc. To use seismic records to predict oil and gas in ...

AI Technical Summary

Problems solved by technology

[0007] The beneficial effect of the present invention is that the present invention provides a method for constructing a seismic inversion low-frequency model, and proposes to use a trend-driven method to gradually restore the real low-frequency background of the physical parameters of the underground medium during the inversion process, which breaks through the existing geological Modeling mainly uses the bottleneck of logging interpolation, which solves the problem that the inversion results are difficult to quantify due to the lack of low-frequency seismic data, greatly improves the inversion accuracy, and has obvious effects in the prediction of complex underground reservoirs

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