基于地震干涉的复杂构造局部成像

    Local imaging of complex structures based on seismic interferometry

    • 摘要: 随着我国油气勘探的不断深入,如今地震勘探成像的重点从大尺度整体成像逐渐转向小尺度复杂构造体成像。受地震波传播机理的限制,小尺度、高陡等复杂构造存在界面反射信息拾取困难、反射能量弱等问题,常规地面地震勘探成像方式难以实现精确成像。通过地震干涉法能够使虚拟观测系统更靠近目标区域,提高对复杂界面的成像分辨率,实现面向目标构造的高精度成像。笔者对地震干涉原理进行理论推导,对小尺度模型进行正演模拟,将生成的干涉道集与实际参考道集进行对比,验证了干涉方法的正确性。将该方法应用到BP气云模型和高陡构造—薄互层模型进行数值试算,并将成像结果与常规RTM成像结果进行对比,证明了地震干涉法可以实现对深层复杂构造的高精度成像。

       

      Abstract: With the continuous advancement of oil and gas exploration in China,the focus of seismic imaging has gradually shifted from large-scale overall imaging to small-scale complex structure imaging.Due to the inherent limitations of seismic wave propagation,small-scale and highly steep complex structures pose challenges such as difficulty in capturing interface reflection information and weak reflection energy.Consequently,conventional surface seismic imaging methods struggle to achieve accurate imaging of these targets.The seismic interferometry method can render the virtual observation system closer to the target area,improving the imaging resolution of complex interfaces, and achieving high-precision target-oriented imaging.This study conducted a theoretical derivation of the seismic interferometry mechanism and forward modeling of small-scale models.By comparing the generated interferometric gathers with actual reference gathers,this study verified the accuracy of the seismic interferometry method.Subsequently,this study applied the method to the backpropagation(BP) gas cloud model and a highly-steep structure- thin interbed model for numerical tests.The imaging results were finally compared with conventional reverse time migration(RTM) results,demonstrating that the seismic interferometry method enables high-precision imaging of deep complex structures.

       

    /

    返回文章
    返回