AVO应用的若干探讨

COMMENTS ON AVO APPLICATION

青海石油管理局勘探开发研究院

Research Institute of Exploration and Development Qinghai Oilfield

本文通过简化Zoeppritz方程的计算,证实了AVO响应主要是地层介质间泊松比异常的反映。分析了柴达木盆地某油田的二条剖面后,发现含油气层与非含油气层都能产生AVO异常,特别难于区分含油层与含水层的AVO异常。但是,用目的层的零入射角时的反射振幅值对“角度道集”进行逐道校正后,其AVO异常却反映了地层间的泊松比差。指出AVO在含油气地层检测中的应用前景和改善AVO响应的设想。

The solution of simplified Zoeppritz equation in the paper confirms that AVO responses mainly reflect the anomalies in Poisson's Ratio for subsurfaces. The AVO analysis on two profiles in Chaidemu Basin unfortunately showed that AVO anomalies might be found in formations whether they were oil / gas-bearing ones. Especially, it is difficult to discriminate AVO amomalies with oil/ gas-bearing formations from those with water-bearing ones. This paper suggest to correct the"common incidence gathers" trace by trace in terms of the amplitude data extracted from the reflection with normal incidence, In this way, the resulting responses will reflect the anomalies in Poisson's Ratio of subsurfaces. Some ideas related to the perspective of AVO together with its improvement in detecting oil / gas-bearingformations is suggested in this paper.