速度异常分析与构造成图技术研究

Analysis of velocity anomaly and structure mapping

在正常沉积情况下 ,随着深度的增加 ,岩性相近地层的层速度逐渐增大 ,平均速度呈由浅到深逐渐增大的趋势。但在某地区出现平均速度逆转现象 ,即浅层平均速度大于深层速度。对这种速度逆转现象 ,应用正演模型技术进行分析研究 ,认为这主要是由于存在较大逆掩断层造成的。为了消除逆断层影响 ,得到合理的平均速度 ,采用处理叠加速度、测井速度和地震地质标定速度相结合的技术 ,研究该区平均速度 ,编制平均速度平面图 ,实现空间变速成图 。

In general average velocity will increase with depth.But in our work area the average velocity reverses, that is, the shallow average velocity is higher than that of deep layers. We studied the velocity reversal with forward modeling, revealing that the velocity reversal was caused by large reversed faults. A reasonable average velocity was derived by the combination of stack velocity, sonic velocity and synthetic fitting velocity. The resulting velocity was used in structure mapping, resulting in improved structural maps.