泥岩墙成像的关键处理技术

Key technologies of mudstone wall imaging

泥岩墙是一种特殊岩性构造,具有纵向构造幅度小、条带分布窄等特点,是块状岩性储层的典型代表。为了准确刻画泥岩墙横向边界和纵向厚度,要求地震资料具有较高的纵、横向分辨率和保真度。一般岩性处理方法的关键在于保幅保真,但往往造成分辨率较低;而高分辨率地震处理方法在提高分辨率的同时,又损失了振幅保真性。本文在分析地震资料处理中影响振幅保真性和分辨率的主要处理技术基础上,从地表一致性振幅处理、CRP道集调谐反褶积和弯曲射线叠前时间偏移等关键技术入手,通过地球物理模型分析不同技术对岩性处理结果的影响,并结合实际地震资料处理,探索出适用于泥岩墙等薄互层成像的岩性处理技术。

The mudstone wall is a special lithologic structure with low amplitude and narrow range,and also a typical representative of massive lithologic reservoir.In order to accurately portray its boundaries and thickness,seismic processing result needs to represent higher vertical and horizontal resolutions and fidelity.Generally,lithologic processing of seismic data unilaterally hinges on preservation of relative amplitudes,but often leads to lower resolution,and conventional high-resolution processing intentionally improves the resolution,yet accompanied by the loss of fidelity.In this paper,three key technologies influencing seismic resolutions and fidelity are first analyzed on a geophysical model,including surface consistent amplitude,harmonizer deconvolution on common reflection point(CRP) and curved-ray Kirchhoff prestack time migration(PSTM),and the technologies can then be concluded to adapt to imaging the mudstone wall.A case proves that the key technologies are available for mudstone wall imaging and have a wide prospect in low-amplitude structure and lithologic reservoir processing.