Calculating method and device of stratum quality factor

Abstract

The invention provides a calculating method and device of a stratum quality factor. The method comprises the following steps of according to seismic data, calculating a first amplitude spectrum corresponding to a first moment and a second amplitude spectrum corresponding to a second moment; carrying out low pass filtering processing on the first amplitude spectrum and the second amplitude spectrum, and acquiring the first estimation value and the second estimation value of corresponding seismic wavelet amplitude spectrums respectively; and according to the first estimation value and the secondestimation value, using a spectral ratio method to calculate the stratum quality factor. In each embodiment of the invention, tedious parameter settings and complex calculating processes during the process of estimating the quality factor by using the spectral ratio method in the prior art are reduced; the accuracy of a stratum quality factor calculating result is increased; the automation of stratum quality factor calculating is realized; manpower is saved; the interference of a human factor to an estimation result is reduced; and the method and the device are high-efficient and practical.

Description

technical field [0001] The application belongs to the technical field of geophysical exploration and processing, and in particular relates to a method and device for calculating formation quality factors. Background technique [0002] In a medium with absorption, the degree of energy loss can be considered fixed for every wavelength of seismic wave propagation, which is related to a physical property of the medium, which can be called the quality factor and can be expressed by the symbol Q . The quality factor Q reflects the absorption and attenuation of seismic waves by the subsurface medium, and is an important parameter for oil and gas detection and reservoir description. [0003] In the prior art, the spectral ratio method can usually be used to calculate the quality factor. In the prior art, when using the spectral ratio method to calculate the quality factor, it is usually necessary to obtain the seismic wavelet amplitude spectrum, but the actual seismic data, the se...

AI Technical Summary

Problems solved by technology

In the prior art, when using the spectral ratio method to calculate the quality factor, it is usually necessary to obtain the seismic wavelet amplitude spectrum, but the actual seismic data, the seismic wavelet is unknown, and the process of obtaining the seismic wavelet requires complex mathematical calculations

For example, using the polynomial fitting method to obtain the seismic wavelet amplitude spectrum, the preset polynomial limits the shape of the wavelet amplitude spectrum, and the fitted seismic wavelet amplitude spectrum is always a single peak with the characteristics of the Lake wavelet The smooth curve, the fitting parameters and effects are not easy to control, the fitting error is large and the fitting effect is poor when the order is low, and the calculation is prone to overflow when the order is high

It can be seen that the method of calculating the quality factor in the prior art is cumbersome in the process of calculating the seismic wavelet, and the accuracy of the calculation result is low, so it cannot be widely used in production

In some cases, the quality factor field can only be established by processors filling in the quality factor based on experience or estimating through trial and error. The workload is heavy and the application results are not stable.

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