以天然气藏的岩石物理实验为基础,总结储集层物性、岩性、含气性与振幅-炮检距关系(AVO)异常响应特征的内在关系,分析气层的AVO异常响应的敏感特征。利用AVO技术对高效气藏和低效气藏进行了变孔隙度和变含气饱和度模拟,得出含气性好的气藏AVO异常属于第三类,含气性差的气藏AVO异常属于一、二类的结论。其结果可以提高AVO解释参数的精度和流体性质识别的准确性,为区域评价提供数值上的参考。
On the basis of petrophysical experiment of natural gas reservoir, the intrinsic relations between reservoir physical property, lithology, gas-bearing nature and AVO abnormal responses from gas reservoirs are summarized, including analysis of the responses sensitivity to the gas reservoirs. For gas reservoirs with high-low effectiveness, the variable porosity and variable gas saturation are simulated by AVO technique, coming to the conclusion that the AVO abnormal responses from gas reservoir with good gas-bearing property belong to Class-Ⅲ, while those from one with poor gas-bearing property belong to Class-Ⅰ and Class-Ⅱ. Therefore, this AVO abnormal response could be used to improve the accuracy of parameters for interpretation and precision of fluid property recognition as references of regional prospecting evaluation.