The Research Of Stabilized And Effective Inverse Q Filtering Method And Its Application In The Near-Surface Compensation

The low velocity layer in near-surface results in many adverse effects for the high-resolution seismic exploration. According to the tight formation, the absorption of high frequency wave components is stronger because of the near-surface low-velocity layer, which results in the serious energy dissipation and distorts the seismic wavelets, so that the seismic exploration resolution is reduced greatly. Based on the knowledge of the study situation about the seismic-wave attenuation inversion and the compensation at home and abroad, the physical mechanism and the factors of seismic attenuation are briefly introduced in the paper, at the same time, it also shows the objective of study and the main contents.The quality factor Q itself reflects the physical characteristics of rock. In order to eliminate the absorption effects of the seismic wave in the propagation process in the underground, do the relative amplitude-preserving compensation and improve the resolution of the seismic data, one of the much effective compensation methods is inverse Q filtering. Stability and efficiency are two issues of general concern in inverse Q filtering. This paper implemented the conventional inverse Q filtering algorithm, at the same time, the stabilized and effective inverse Q filtering algorithm which works for a general earth Q-model, variable with depth or traveltime is deduced. For the purpose of testing the effects of the stabilized and effective inverse Q filtering method, it is applied in the theoretical model data, and the characteristics of the method are also summarized. Finally, the stabilized method is compared with the conventional method, and is applied in the actual seismic data.The accurate Q estimation is the prerequisite of inverse Q filtering. In this paper, several general Q estimation methods are presented briefly, and a method for estimating seismic absorption based on the peak frequency shift is mainly introduced, and then this paper shows how to obtain the peak frequency accurately in the low signal-noise ratio seismic data. Then the Q estimation method is tested by the model data, and the characteristics of seismic wave attenuation and attenuation inversion are analyzed in the propagation process. Finally the algorithm of Q estimatimation in near-surface is developed in the multi-micro-logging data. And then compensation in the near-surface is completed in the real seismic data.Some results are obtained, and they are important in the quest to improve the resolution of seismic images, better interpret the effects of AVO invert for material properties and so on.