To clarify the relationship between seismic acquisition bin and migration imaging is helpful to obtain high-resolution seismic data and of great significance to evaluating lithological traps and exploiting petroleum reservoirs.According to the drilling data from the HZ oilfield in the Pearl River Mouth basin in the South China Sea and in combination with studies on the superimposed relationship of sand bodies,the mapping of pinch-out points,stratigraphic resolution and steep-dip formation,four sets of sand-body models varying in scale and occurrence have been designed,which uses the elastic wave equation to accomplish compressional seismic gather,thereby simulating the imaging with changing acquisition bin and discussing deeply the influence of the acquisition bin on migra tion imaging.The results indicate that small bin acquisition can avoid the interference of spatial aliasing,protects the high frequency information of steep dip angle of diffraction arc,and reduces the influence of anti-aliasing operator on the energy homing of the sand body boundary and steep-dip strata.High-density seismic data acquisition have been conducted twice on the K22 sand body of the HZ oilfield (the acquisition bin is 6.25 m × 12.5 m in size),which provide the basis for operations like reservoir prediction and wellsite deployment.As proved by the successful encounter of thick oil layers of 16 m in thickness by an appraisal well,the small acquisition bin can provide reliable data for the evaluation of steep-dip structures and the exploration and development of lithological reservoirs.%厘清地震采集面元与偏移成像的关系,有助于获得高分辨率地震,对岩性圈闭评价及油藏开发具有重要意义.根据南海珠江口盆地HZ油田已钻井数据,结合砂体的叠置关系及尖灭点刻画、地层分辨力和陡倾角地层研究等,设计了4组不同尺度与产状的砂体模型,应用弹性波动方程实现纵波道集正演,模拟不同面元采集的成像结果,深入讨论采集面元对偏移成像的影响.结果表明,小面元采集能避免空间假频干扰,保护绕射弧的陡倾角高频信息,降低反假频算子对砂体边界、陡倾角地层能量归位的影响.对HZ油田K22砂体进行了实际二次高密度地震资料采集(采集面元为6.25m×12.5m),在此基础上完成储层预测、井位部署等,评价井成功钻遇16m厚油层,证实了小面元采集能为高陡构造评价及岩性油气藏的勘探开发提供资料保障.
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