【摘要】 针对常规叠前深度偏移成像技术难以将溶洞型储集层的多次绕射波完全归位、难以准确成像溶洞分布这一难题,引入了频率域声波逆散射成像方法。该方法直接从炮集地震资料出发,利用散射记录的逆时传播波场与入射波场褶积得到扰动速度的分布,将速度模型迭代更新与构造成像融为一体。溶洞模型数值模拟和物理模拟资料的处理效果表明,即使初始速度模型存在12%的误差,该方法仍可以将溶洞产生的多次绕射波较好地归位,较准确地将溶洞的形状、位置成像。同时,对常规偏移成像方法和逆散射成像方法影响溶洞成像精度的主要因素进行了定量分析,为提高溶洞型碳酸盐岩油气藏勘探精度提供了理论指导。图11参23更多还原

【Abstract】 To solve the problem of the traditional pre-stack depth migration technique being difficult to collapse multi-diffraction completely and to image the distribution of cavern reservoirs accurately,this paper introduces an inverse-scattering imaging method based on frequency-domain acoustic wave equation.The method is used to process the shot gather directly and it can obtain the direction of perturbation velocity by convolution of reverse-time wavefields of the scattered seismic record with incidence wavefields,which combines updating velocity iteratively and stratum imaging together.The good image profiles of applying the inverse-scattering imaging method to the synthetic record and the laboratorial data of cavern models show that the method can collapse multi-diffraction better and image the distribution and the shape of caverns accurately even if the initial velocity model has an error of 12%.In addition,a quantitative analysis of factors influencing the cavern imaging accuracy in the traditional and new methods provides a theoretical guide to improve the exploration accuracy of vuggy carbonate reservoirs.更多还原