面炮成像、控制照明与AVA道集  

Plane wave source imaging,controlled Illumination and AVA gathers

作　　者：王兆湖[1,2] 陈湛文[3] 崔兴福[4] 

机构地区：[1]吉林大学,地球探测科学与技术学院,长春130026 [2]大庆石油管理局钻探集团物探公司,大庆163357 [3]中国石油大学资源与信息学院,北京102249 [4]中国石油勘探开发研究院地球物理所,北京100083

出　　处：《地球物理学进展》2008年第3期826-833,共8页Progress in Geophysics

摘　　要：基于波场延拓的叠前深度偏移是实现复杂构造地质体成像的最可靠方法,但存在着计算量大、对观测系统适应性差等缺点.面炮偏移是波动方程实现精确叠前成像的另一类方法,具有较高的计算效率,不存在偏移孔径问题,而且可以通过控制照明方法,解决平面波在目标区域的能量补偿问题.本文采用面炮成像技术进行叠前深度偏移,通过对面炮震源下行波场的质量控制和优选射线个数和范围,以达到最佳的成像效果.采用控制照明技术,较大地提高了目标地层的成像精度.与此同时,得到振幅随入射角变化(AVA)道集,有利于叠前振幅解释和储层岩性预测.数据实验表明面炮成像技术是一种快速有效的方法,其成像精度与单平方根算子的共炮点道集偏移和双平方根算子的共中心点道集偏移相当,但在计算速度上要快得多,而且易于并行计算.Prestack depth migration based on wavefield continuation is the most reliable method for complex structure imaging in subsurface, whereas, it needs large computation costs and has poor adaptive geometry. Plane wave source migration is another way of wave equation-based accurate prestack imaging with high efficiency and without migration aperture problem. Moreover, wavefield energy can be compensated at the target zone by controlled illumination. In this paper, prestack depth migration accomplished by the control of downgoing wavefield of plane wave and selection of the number and range for the rays, in order to gain the best result of imaging. Moreover, the controlled illumination techniques are applied to enhancing the precision of interesting area. Simultaneously, the amplitude versus incident angle （AVA） gathers can be acquired on the benefit of amplitude interpretation and reservoir lithologic prediction. Numerical calculation indicates that plane wave source imaging is a rapid and efficient method with less computation cost and easy parallel algorithm, in similarity of precision with single square-root operator imaging for common shot gathers and double square-root operator imaging for common middle point gathers.

关 键 词：叠前深度偏移 波场延拓 面炮成像 控制照明 AVA道集 

分 类 号：P631[天文地球—地质矿产勘探]