高斯束成像技术及其应用

Gaussian beam migration and its application.

(中国石油大学(华东)地球资源与信息学院,山东青岛266555)

Guo Chaobin,College of Geo-resource and Information,China University of Petroleum (East China),Qingdao 266555,China

高斯束偏移是Kirchhoff积分偏移的一种替代方法。依据高斯束偏移的基本原理,给出了高斯束偏移方法在保幅成像、角度域成像和起伏地表条件成像中的应用原理和方法,探讨了高斯束偏移中初始宽度、频带宽度和波束采样间隔等重要参数的选取原则,采用数值模型及实际资料对高斯束偏移方法的应用效果进行了验证。通过上述研究得出以下结论:①在一定的偏移距范围内,保幅高斯束偏移能正确地恢复地下界面真实的反射率;②同保幅Kirchhoff偏移相比,保幅高斯束偏移对复杂构造的成像效果有明显提高,而计算时间仅为保幅Kirchhoff偏移的1.6倍左右;③高斯束偏移在陡倾构造处的成像效果要优于常规的波动方程偏移;④高斯束偏移对起伏地表条件具有良好的适应性。

Gaussian beam migration (GBM) is a ray based imaging method.Based on the basic rules of GBM,we presented applications of GBM to amplitude-preserved migration,angle domain imaging and imaging from topographic surface,discussed the selection criteria of some important parameters of GBM such as initial width,bandwidth,and sampling spacing of beams,and validated the effectiveness of GBM with numerical experiments on both synthetic and real data.According to the mentioned study,we get the following conclusions:①the amplitude-preserved GBM can recover the true reflectivity of subsurface within specified offset;②compared to Kirchhoff migration,amplitude-preserved GBM has a better imaging quality of complex structures and its computing time is only 16 times to that of preserved amplitude Kirchhoff migration;③GBM has a better imaging quality of steep dips than the traditional wave equation migration;④GBM has good adaptability to topographic surface.