论文标题
在不确定性下,地震成像中的反向时间迁移的编码器深度替代
An encoder-decoder deep surrogate for reverse time migration in seismic imaging under uncertainty
论文作者
论文摘要
由于存在多种不确定性来源,地震成像面临挑战。数据测量,源定位和地下地球物理特性中存在不确定性。反向时间迁移(RTM)是一种高分辨率深度迁移方法,可用于提取诸如储层本地化和边界之类的信息。但是,RTM是耗时的和数据密集型的,因为它需要计算两倍的波方程才能生成和存储成像条件。当将RTM嵌入不确定性定量算法(如Monte Carlo方法)中时,由于高输入输出尺寸,其计算复杂性增加了很多倍。在这项工作中,我们建议在不确定性下针对RTM的编码器深度学习替代模型。输入是速度场的集合,表达不确定性并输出地震图像。我们通过数值实验表明,替代模型可以准确地重现地震图像,更重要的是,从输入速度字段到图像集合的不确定性传播。
Seismic imaging faces challenges due to the presence of several uncertainty sources. Uncertainties exist in data measurements, source positioning, and subsurface geophysical properties. Reverse time migration (RTM) is a high-resolution depth migration approach useful for extracting information such as reservoir localization and boundaries. RTM, however, is time-consuming and data-intensive as it requires computing twice the wave equation to generate and store an imaging condition. RTM, when embedded in an uncertainty quantification algorithm (like the Monte Carlo method), shows a many-fold increase in its computational complexity due to the high input-output dimensionality. In this work, we propose an encoder-decoder deep learning surrogate model for RTM under uncertainty. Inputs are an ensemble of velocity fields, expressing the uncertainty, and outputs the seismic images. We show by numerical experimentation that the surrogate model can reproduce the seismic images accurately, and, more importantly, the uncertainty propagation from the input velocity fields to the image ensemble.