摘要：Wave equation wave field numerical modeling technology is applied to the observation that deep layer imaging is difficult below a screening layer of high-velocity basalt. Three simple high-velocity basalt models are designed on the basis of basalt formation characteristics. The analysis of deep-layer reflection seismic signal energy shows that lowfrequency seismic signals are capable of both penetrating the thin high-velocity basalt layer and reducing the diffraction noise caused by the rough surfaces. The simulation experiment of a complete 2D basalt model confirms that the low-frequency signals can be used to boost the quality of deep-layer imaging under the high-velocity basalt layer and achieve good results in low-pass filter processing of actual data.

摘要：膏盐层作为一种很好的烃源岩和极好的盖层与油气储层具有密不可分的关系,但是,膏盐层具有的特殊性质使得其下伏目标地层成像困难。为此,以济阳坳陷HJ复杂膏盐区为目标区,首先通过分析膏盐层的地质和地球物理特征,说明了造成其下伏地层成像困难的主要原因——原位地层条件下处于蠕动状态非均匀分布的膏盐层对地震波场的强烈吸收和散射作用。然后设计了一个简化的膏盐层模型,采用波动方程粘弹介质波场数值模拟技术,分析了单道记录中以膏盐层为界的浅层和深层地震反射信号振幅谱的频率差异,证明了介质对波场的散射和吸收作用与地震信号的频率密切相关,高频信号衰减快,低频信号具有较强的抗散射和抗吸收能力,更易于穿透处于蠕动状态的非均匀膏盐层。最后根据目标区实际地质情况,建立了膏盐层地质模型。模拟数据分频成像处理表明,利用低频信号可以提高深层的成像质量。