基于保幅波动方程的广义高阶屏地震偏移成像方法  

Seismic migration imaging method of generalized high-order screen based on preserved-amplitude wave equation

作　　者：杨瑞娟[1] 刘定进[1] 吴伟[1] 郝军[2] 鲍峥[2] 罗申玥[2] 

机构地区：[1]中国石油化工股份有限公司石油物探技术研究院,江苏南京211103 [2]中国石油化工股份有限公司江苏油田分公司石油物探技术研究院,江苏南京210046

出　　处：《物探化探计算技术》2013年第5期581-588,共8页Computing Techniques For Geophysical and Geochemical Exploration

基　　金：国家自然科学基金(41274124);国家科技重大专项(2011ZX05006-004)

摘　　要：原始地震数据中饱含丰富的反映相位的走时信息和反映反射率的振幅信息。基于波场延拓理论的波动方程保幅地震偏移成像,是在给出正确构造成像位置的同时也给出真实反射振幅的有效完善。基于全声波方程,利用严格的解耦理论进行单程波动保幅分解,得到一个由波场传播项与振幅补偿项构成的,在走时与振幅上满足全声波方程对应的程函方程与输运方程的保幅单程波动方程;利用摄动理论进行单平方根算子渐进展开,推导出基于保幅波动方程的广义高阶屏地震偏移算子方程。模型测试和实际资料处理表明,该方法不但可以凭借更准确的相位归位和散射能量聚焦提高构造成像精度,而且输出了能更正确反映地下反射属性的能量信息,从而可以为更深层次的勘探开发,提供地球物理技术支撑。Original seismic data contain rich travel-time information which can reflect phases and amplitude information reflecting frequencies. Waveform equation preserved-amplitude seismic migration imaging based on wave field prolongation theories is an effective improvement which can give true reflection amplitudes as well as the correct locations of structure im aging. This paper, firstly, started from full sound wave equation, and then performed one-way wave preserved-amplitude decomposition according to the strict decoupling theory to got a preserved-amplitude one-way wave equation. This one-way wave equation was formed by wave field propagation items and scattering compensation items. The equation satisfied with eikonal equation and transport equation which corresponded to full sound wave equation on travel time and amplitude. After that this paper derived a generalized high-order screen seismic migration operator equation based on preserved-amplitude wave equation using progressive expansion of single square root operator according to the perturbation theory. Theoretical model testing and real data processing indicated that this method had better imaging precision： It could make scattering ener gy be focused and migrated to the correct position. At the same time, the imaging gathers had amplitude information which could reflect subsurface reflectivity correctly providing more accurate seismic reflection information for sequent velocity mod- eling and AVO/AVA seismic attributes analvsis.

关 键 词：波动方程 叠前深度偏移 保幅偏移 摄动理论 广义高阶屏 

分 类 号：P631.443[天文地球—地质矿产勘探]