Quality factor spectrum of stratum and solving method thereof

A quality factor and formation technology, applied in seismic signal processing and other directions, can solve problems such as large differences and achieve the effect of increasing utilization

CN102023311AInactive Publication Date: 2011-04-20CHINA UNIV OF PETROLEUM (EAST CHINA)
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Patent Information

Authority / Receiving Office
CN · China
Current Assignee / Owner
Publication Date
2011-04-20
Estimated Expiration
Not applicable · inactive patent

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Abstract

The invention provides a quality factor spectrum of stratum and a solving method thereof. The quality factor value is solved by using a frequency spectrum ratio method based on zero offset VSP (Vertical Seismic Profiling) data. The method specifically comprises the steps of: selecting a reasonable first arrival and time window parameter, carrying out spectrum analysis on the original section; picking a peak frequency in a frequency spectrum effective band to obtain the smoothed trend; carrying out normalization on the original frequency spectrum, then correcting the frequency spectrum by using the smoothed trend; comparing by using adjacent channels of frequency spectrums to obtain frequency spectrum ratio data for the combination; and aiming at the combined frequency spectrum ratio data, solving a plurality of quality factor Q values or carrying out Q scanning by using a Q value attenuated channel compensating method to obtain coefficients similar to a reference channel frequency spectrum to form a Q spectrum, and obtaining a stable Q value through explanation of the Q spectrums. The invention has the advantages of eliminating the influence of the frequency spectrum yield value on the linear fitting as far as possible, increasing the utilization ratio of the frequency spectrum information, and obtaining a more reasonable Q value.
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Description

Technical field

[0001] The invention belongs to the field of seismic data processing, and is a stable calculation method for formation quality factors. Background technique

[0002] Due to the absorption and attenuation of the formation, the reflected wave energy received by the ground will be significantly reduced. The description parameter of formation attenuation effect is the most commonly used quality factor. There are many extraction methods of quality factor, which are mainly divided into four categories: time domain, frequency domain, time-frequency domain and some other inversion methods. The existing quality factor extraction methods are mainly used in zero-bias VSP data, ground CMP data, multi-wave data and surface wave data. Various methods have their well-posedness, and the results obtained by using different methods may vary greatly when calculating the quality factor. This requires exploring a more stable quality factor calculation method. Contents of the...

Examples

Embodiment Construction

[0028] The quality factor Q of the formation is an important parameter to characterize the attenuation of the formation. It describes the incomplete elastic characteristics of the medium and is the internal essential characteristic of the formation.

[0029] The present invention proposes the concept of quality factor spectrum (Q spectrum). Using zero-bias VSP data, through reasonable first-arrival picking and time-window selection, the spectrum peaks in the effective frequency band are compared, and trend smoothing is performed on the basis of the obtained data, and the smoothing trend is added to the normalized original In the spectrum; then use the concept of spectrum ratio to compare adjacent channels, combine the logarithmic ratio obtained from the comparison, and combine different data, and then perform the quality factor calculation according to the slope of the straight line obtained by fitting each group of combined data Find, or according to the concept of similarity...