三维保幅弯曲射线Kirchhoff叠前时间偏移方法与应用

3-D Bend-ray amplitude-preserving Kirchhoff pre-stack time migration and applications

地震勘探是寻找油气的重要手段之一.对于复杂构造地区,地震偏移成像成为地震资料处理流程中最重要的一环.由于叠前时间偏移尤其是Kirchhoff叠前时间偏移适应性强、计算效率高、成本低的自身特点,该方法在油气勘探中发挥着重要作用.对于该方法的成像精确性的研究有着重大的科研和工业价值.本文利用弯曲射线方法计算走时,加入保幅权函数,结合去假频技术、MPI并行技术,以SEG三维盐丘模型和某区域三维实际资料为研究对象,实现三维保幅弯曲射线Kirchhoff叠前时间偏移.将该方法偏移结果与传统的叠前时间偏移方法偏移结果进行对比分析,结果表明:本文采用的方法主要有以下两方面的优越性:第一,引入了弯曲射线计算走时,实现了弯曲射线叠前时间偏移,提高了成像的精确性;第二,引入了保幅权函数,实现了保幅叠前时间偏移,提高偏移结果的信噪比.

Seismic exploration is an important method of seeking oil and gas. For complex structure region, seismic migration imaging becomes an important part of seismic data processing. Because Kirchhoff pre-stack time migration has good adaptability, high efficiency, and low cost, this method plays an important role in oil and gas exploration. The study on this method has great research and industrial value. Taking 3-D SEG/EAGE salt dome model and one 3-D practical data as research objects, the authors achieve 3-D bend-ray amplitude-preserving Kirchhoff prestack time migration by using bend-ray travel time calculation and amplitude- preserving weight function. Comparing with the traditional method, the results show that the newmethod has two {ollowing advantages~ first, bend-ray travel time calculation improves the accuracy of imaging~ second, amplitude-preserving weight function enhances imaging resolution.