High-accuracy Frequency Attenuation Technology And Its Application

More higher accuracy exploration is required with deeper exploration.A hard problem in the front of geophysics workers is how to identify oil or gas and decrease exploration risk.Since years some geophysics workwers have devoted themselves to the research about it.Among them frequencies attenuation application of seismic datas become hotspot.Generally speaking oil or gas is relevant to frequencies attenuation,but because of the complex media underground,wave equation is hard to numerically model the seismic wave travel. Some times seismic attribute cannot be suitable completely for all exploration area, this also urges the geophysics workers to continue to try hard.The high accuracy exploration requires each step of frequencies attribute extracted is high accuracy, including the high quality seismic data, the high accuracy time-frequency analysis method, the high accurancy absorption coefficient extracted and background removed. If the attributes extracted have the very high time resolution we must guarantee the very high time resolution of seismic signal's analysis.The wavelet transformation has the huge promotion potential in time resolution in this aspect.The flexibility of the wavelet basis choosed decide that through structuring appropriate wavelet function high time resolution gained.At the same time Wavelet transform has the inherent defect we must overcome it in order to improve the accuracy of absorption coefficient.This article is revolving the high accuracy frequency attenuation technology, first we state that conventional time-frequency analysis methods just for the actual need of the frequency attenuation ,then we propose a new time-frequency analysis method - time-frequency three parameters wavelet transformation which might through adjusting three parameters of three wavelet to change the window narrow or width in order to achieve the temporal frequency resolution of seismic datas, on the other hand when translate the scale-time wavelet transformation map into time-frequency, the high-frequency aliasing energy is pulled down seriously, which creates the false appearance to the high frequency attenuation explanation. The time-frequency three parameters wavelet transformation uses for reference of the phase correction from the S transformation to enable this question solved. The fitting method of high frequency is used nonlinear fitting which has hingh accuracy and stability.Besides,this article involves T-k energy associated with the frequency attenuation as well as instantaneous average frequency instantaneous bandwidth .