高斯波束共角度保幅深度偏移

Gaussian beam common angle preserved-amplitude migration

高斯波束偏移是一种准确、灵活、高效的深度偏移方法,不但具有接近于波动方程偏移的成像能力,还可以对陡倾角地层以及各向异性介质进行成像。由于高斯波束偏移过程中含有地下射线的传播角度信息,因而可以利用此角度信息直接提取角度域共成像点道集,而不需要波动方程偏移中复杂的映射转换。本文首先介绍了高斯波束偏移的基本原理,然后实现了基于互相关成像条件的保幅高斯波束偏移,并提出了角度域共成像点道集的提取方法。模型和实际资料的试算分析表明,此方法是有效的。

Gaussian beam migration is an accurate,flexible and effective migration method,it’s imaging ability could approaches that of wave-equation migration,moreover the method could image steep strata and anisotropic medium.In Gaussian beam migration process the propagation angle information for the subsurface rays is generated,the information then can be utilized to directly extract the common imaging point gathers in angle domain,as a result the complex mapping and transform in wave-equation migration are not needed any more.In this paper the basic principle of Gaussian beam migration was introduced,then the preserved-amplitude Gaussian beam migration which is based on cross-correlation imaging conditions was realized,and the extraction method for common imaging point gathers in angle domain was proposed.The trial calculations for modeling and field data proved the effectiveness of this method.