Resolution controllable envelope generating operator-based multi-scale full-waveform inversion method

Abstract

The invention discloses a resolution controllable envelope generating operator-based multi-scale full-waveform inversion method. The method includes the following steps that: a resolution controllable resolution envelope generating operator is built, and the frequency band range of seismic data used for inversion is controlled by adjusting parameters; a full-waveform inversion method is built according to the resolution controllable resolution envelope generating operator, and the gradient of an objective function relative to model parameters and the calculation formula of iteration step size are inferred; and a steepest descent method is adopted to iteratively update the model parameters until algorithm conditions are satisfied. The method has better capacity of overcoming the problem of cycle skipping, is more suitable for the modeling of a lithologic oil and gas reservoir velocity model, and has more obvious advantages when seismic data are lack of low-frequency information or dominant frequencies in the seismic data are too high. With the resolution controllable envelope generating operator-based multi-scale full-waveform inversion method of the present invention adopted, the seismic data on which the resolution-controllable envelope generating operator has acted has enough low-frequency information regardless of whether the seismic data have sufficient low-frequency information or not; and the parameters can be adjusted, and multi-scale inversion can be realized.

Description

technical field [0001] The invention belongs to the technical field of geophysical exploration, and relates to an earth model P-wave velocity parameter inversion method, in particular to a multi-scale full waveform inversion method based on a resolution controllable envelope generation operator. Background technique [0002] Oil and natural gas are strategic resources related to national economic development and national security. Further promoting the exploration and development of oil and gas resources in my country is a major national strategy. Lithologic reservoirs will be the most important exploration and development targets in my country for a long time to come. Seismic exploration method is the main method of oil and gas exploration, and velocity parameter is an important parameter for oil and gas detection. Most of the lithologic reservoirs in my country have a thin interbedded structure vertically and strong heterogeneity laterally. How to describe the velocity pa...

AI Technical Summary

Problems solved by technology

Although there are some successful application cases of multi-scale methods, such methods cannot fundamentally overcome the cycle-skipping problem.

When this type of method is applied to actual data, the following problems will be encountered: it is usually difficult to establish a sufficiently accurate initial model; the low-frequency information of actual data is often affected by noise; the offset distance of actual data is often limited

But this objective function still suffers from the cycle skipping problem

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