Near-surface Absorption Compensation And Its Application In AVO Analysis

Near-surface low velocity brings a lot of adverse effects to precision seismic exploration. Relative to deep tight formation, the loose near-surface low velocity absorbs seismic frequency signal attenuation is very serious, it leads to changing in the near-surface lithology space, excitation wave and excitation energy also had a serious space changes and it caused changes in the final imaging and reservoir reflection seismic attribute information, this change is much larger than the oil and gas geological reservoir information changing factors. The quality factor Q itself reflects the physical characteristics of the rock formation, in order to eliminate the seismic wave propagation in near-surface medium of dispersion and absorption, improve the resolution of seismic data, it is an effective way to use anti-seismic waves Q filter to compensate.At first, this paper described the influence of seismic wave propagation in the near-surface and anti-Q filter element method to analyze the physical mechanism and characteristics of attenuation, and the establishment of a theoretical model of the surface absorption and attenuation; secondly, using the Q value of the absorption compensation techniques to quantify estimated Q values obtained construction market ideas and methods. By measuring the amount of near-surface attenuation, attenuation law found to give a near-surface absorption remedy and compensation on the basis of up to absorb the near-surface decay and pre-stack AVO inversion. Finally, through AVO attribute analysis, AVO processing model to give process and applied to the actual seismic data, thereby improving the resolution of seismic data while improving the accuracy of AVO hydrocarbon detection.By compensating the near-surface absorption and its application in AVO analysis, it improved the resolution of seismic data at the same time, it corrected the impact of near-surface rationally and quantitatively, improved the pre-stack AVO inversion precision, for the benefit of regional and target well bit preferably provides reliable data protection.