基于正演模型的砂泥岩薄互层AVO特征分析

Thin inter-bed AVO characteristics analysis based on forward model

对薄互层地震反射和波场特征的研究是进行薄储层描述和油气预测的基础。文中从薄互层地震反射特征的理论研究出发,剖析了四类AVO响应特征;通过构建不同厚度、速度、密度及层间组合关系的砂泥岩薄互层理论模型,利用反射率法对不同的模型进行波场正演,探究了影响薄互层垂直反射特征(主要是薄互层调谐曲线的变化规律)的主要因素以及不同薄互层结构对AVO响应特征的影响;总结出砂泥比和互层结构等因素对薄互层AVO反射特征的影响规律,可用于实际地震资料的薄互层精细解释。

The study of thin inter-bed seismic reflections and wavefield characteristics is the basis for the thin bed reservoir characterization and hydrocarbon prediction.First based on academic analysis of thin inter-bed seismic reflections,we study four types of amplitude versus offset(AVO)characteristics.Then we establish different thin inter-bed models with different thickness,velocity,and density.Finally we use the reflectivity method for the wavefield forward modeling of these models.The main factors affecting thin inter-bed vertical reflection characteristics and the influence of different thin inter-beds on AVO response characteristics are investigated.The paper summarizes the influences of sand-mud ratio,inter-bed structures,and other factors on AVO characteristics,which may be helpful for the thin inter-bed interpretation.