【摘要】 针对塔中地区碳酸盐岩储层开展波动方程正演模拟,采用有限差分法求解波动方程,重点揭示垂向长串珠形成机理。结果表明,单个高度较大溶洞、垂向叠置溶洞和走滑断裂与地层复合均可形成绕射波,对这些绕射波进行偏移成像,即可在垂直方向上形成长串珠状反射。单个溶洞形成的双串珠中,顶底界面反射系数不同导致顶部串珠波形为两谷夹一峰,底部串珠波形为两峰夹一谷;双溶洞形成的双串珠为反射特征相同的两个串珠,由此可加以区分;层面与走滑断裂复合也会导致垂向上多个串珠的存在,前提是碳酸盐岩内幕分层现象明显,且沿走滑断裂有溶蚀现象存在。这些结论对于明确复杂地震响应的成因机制,进而认识其地质模式,指导勘探开发具有一定借鉴作用。更多还原

【Abstract】 Regarding the carbonate reservoir in Tazhong Area,wave equation forward modeling were conducted and the finite difference algorithm was used to solve the wave equation in order to disclose the formation mechanism of vertical "long string beads".The study results show that the diffraction wave could be formed by single and big cave,vertical overlap cave,sliding fault and the formation composition,conducting migration imaging for the diffraction wave could form vertical "long string beads" reflection.For the double string bead formed by single cave,the different reflection coefficients between the top layer and bottom layer lead to a top string bead waveform,like two troughs and one peak,and a bottom string bead waveform,like two peaks and one trough.The double string bead formed by double caves is the two string beads with same reflection characteristics,it is easy to distinguish,the combination of strata and the sliding fault could result in the formation of several vertical string beads,the pre-assumption is that there should be obvious inner layers for the carbonate rocks,and the erosion should exist along the sliding fault.Those conclusions could be referred when studying formation mechanism of the complicated seismic response,understanding the geological mode and guiding the exploration and development.更多还原