【摘要】 基于波动方程的照明分析可以直观地反映在确定的地震观测系统下地下介质中地震波能量的分布,但是难以深入分析弱照明区域的成因并提出解决措施.针对该问题,提出一种新的复杂构造地区地震观测系统设计方法.利用波动方程照明技术定量评价不同观测系统在目标层的照明能量分布;通过波动方程正演模拟分析目标层位弱照明的成因,提出针对性的解决措施;对模拟数据的叠前深度偏移成像结果进行定量分析,优选最有利于成像处理的观测参数.将该方法应用于ZB地区逆掩推覆构造模型,结果表明,在该地区8km的排列长度最有利于提高信噪比;在地面30.0～30.5km进行炮点加密,并采用6km的排列长度进行接收,可以明显改善弱照明区域的成像质量.更多还原

【Abstract】 Wave equation based illumination analysis can directly give the seismic wave energy distribution in subsurface for a given seismic geometry,but it cannot deeply analyze the cause to the weak illumination zone,or give solutions.A new seismic survey design method for complex structural area was presented.The illumination energy distribution in target layer was evaluated by using the wave equation illumination method;the causes to the weak illumination were analyzed by using wave equation forward modeling,and efficient solutions were presented;the best acquisition parameters were selected according to a quantitative comparison between different prestack depth migration results of the modeling data.Application of this method for overthrust nappe structural model in ZB area showed that a spread length of 8 km is optimal to improve the signal noise ratio in this area;to add shot points in the range of 30.0 — 30.5 km on the ground and receive by 6 km spread length can noticeably improve the imaging quality of the weak illumination zone.更多还原