针对不同地质目标的叠前时间偏移成像解释评价

随着计算机硬件和地震勘探成像技术的发展，叠前时间偏移正逐步替代常规的NMO加DMO加叠后时间偏移成为地震数据成像处理方法的主流。但对于不同的地质目标，叠前时间偏移的成像效果是否优于常规NMO加DMO加叠后时间偏移的成像效果呢？为此，从地震数据成像处理方法、处理流程和处理参数等方面进行了讨论，并基于某地区三维数据常规处理结果和叠前时间偏移处理结果，针对不同地质目标进行了剖析与评价。认为：叠前时间偏移成像的垂向分辨率较常规处理明显降低，但对于空间波阻抗变化明显的河流和断层，叠前时间偏移成像的空间分辨率要高于常规处理；对于小于1／4波长的叠置薄储层，叠前时间偏移成像的垂向和空间分辨率低于常规处理结果。

Valuation of pre-stack timemigration and imaging with different geological targets .

With the increase of computer power and the development of seismic imaging technologies, pre-stack time migration (PrSTM) has gradually replaced the conventional process of NMO DMO Post-stack time migration (N D PoSTM) and become a mainstream of processing in migration and imaging. In order to make it clear if PrSTM has advantages over N D PoSTM in imaging when geological targets vary from case to case, we study seismic data migration and imaging in terms of processing methods, sequences and parameters. We also analyze and evaluate the results obtained by 3D N D PoSTM and PrSTM respectively with the datasets of different geophysical targets. The results indicate that the vertical resolution of PrSTM is obviously lower than that of N D PoSTM, but bas higher spatial resolution for the channels and faults with a sharp variation of spatial impedance. If the thickness of overlapped thin beds is less than 1/4 of a wavelength, both vertical and spatial resolutions of PrSTM are lower than those of N D PoSTM.