地震波干涉偏移和偏移反演成像是近年来十分活跃的两个研究领域.干涉偏移提供了一个新的地震波数据成像工具,而偏移反演则提供了高逼近度地震成像.二者的共同目的是改善传统直接偏移方法的成像效果,展宽成像区域并提高成像的分辨率.本文研究干涉偏移方法和偏移反演方法对于地震成像效果的影响,探讨二者在提高成像分辨率上的异同.对于偏移反演,通过建立正则化模型,研究了预条件共轭梯度迭代正则化方法及改进措施,并通过绕射点模型数值模拟验证了该方法比直接偏移能够提高振幅的保真度和成像的分辨率.对于干涉偏移和偏移反演这两种方法,对层速度地震模型进行了数值模拟.结果表明干涉偏移和偏移反演成像方法比传统的偏移方法在成像效果上是更加有效的,因而对于实际的地震成像问题很有应用前景.
Interferometric migration and migration inversion are two active research fields in seismic imaging. The interferometrie migration supplies us a new tool for seismic data imaging, while the migration inversion supplies us an improved resolution of imaging of seismic data. Both methods aim to improve the performance of the traditional migration imaging tool. In this paper, we consider comparison of the interferometric migration with the migration inversion. For migration inversion, we consider regularization techniques and propose a preconditioning regularized conjugate gradient method, numerical simulations on diffraction point models verify that the regularization method could yield higher resolution and more accurate amplitude than the traditional migration technique. To show the potential for application of these methods, we perform synthetic seismic data imaging. Numerical experiments based on layered velocity model are developed. The numerical results indicate that both methods are useful for seismic migration imaging and may be used for practice in the future.