Seismic images of Earth's subsurface are essential for oil and gas exploration. Gaussian beam migration is popular for seismic imaging owing to its flexibility and efficiency of implementation. However, the practical use of classic Gaussian beam migration is limited for complicated structures such as subsalt because of poor seismic illumination in those areas. We propose an illumination-compensated Gaussian beam migration under the framework of least-squares migration, enhancing the subsalt imaging effectively. A novel scheme based on the Born modelling and migration of Gaussian beam is developed to estimate the point spreading function, with which the illumination compensation can be efficiently implemented in the local wavenumber domain. As the aim of least-squares migration, the proposed illumination-compensated Gaussian beam migration produces true-amplitude images in subsalt areas, which facilitates the seismic interpretation of subsalt structures. The total computational cost of the proposed method includes one Born modelling process and two conventional Gaussian beam migrations, and thus it is much more efficient than the classic least-squares migration which requires multiple iterations. Numerical examples have demonstrated the effectiveness of the adaptive strategies, manifesting applicable potential in oil and gas exploration of subsalt targets.

中文翻译：

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用于增强盐下成像的照明补偿高斯光束偏移

地球地下的地震图像对于石油和天然气勘探至关重要。高斯光束偏移因其灵活性和实施效率而在地震成像中很受欢迎。然而，经典高斯光束偏移的实际应用受到盐下等复杂结构的限制，因为这些区域的地震照明较差。我们在最小二乘偏移的框架下提出了一种光照补偿的高斯光束偏移，有效地增强了盐下成像。开发了一种基于波恩建模和高斯光束迁移的新方案来估计点扩展函数，利用该方案可以在局部波数域中有效地实现光照补偿。作为最小二乘迁移的目标，拟议的照明补偿高斯光束偏移在盐下区域产生真实振幅图像，这有助于盐下结构的地震解释。所提出方法的总计算成本包括一个 Born 建模过程和两个常规的高斯光束偏移，因此它比需要多次迭代的经典最小二乘迁移更有效。数值算例证明了自适应策略的有效性，显示了在盐下目标油气勘探中的应用潜力。因此它比需要多次迭代的经典最小二乘迁移更有效。数值算例证明了自适应策略的有效性，显示了在盐下目标油气勘探中的应用潜力。因此它比需要多次迭代的经典最小二乘迁移更有效。数值算例证明了自适应策略的有效性，显示了在盐下目标油气勘探中的应用潜力。