In this paper, wavefield storage optimization strategies are discussed with respect to reverse-time migration (RTM) imaging in reflection-acoustic logging, considering the problem of massive wavefield data storage in RTM itself. In doing so, two optimization methods are proposed and implemented to avoid wavefield storage. Firstly, the RTM based on the excitation-amplitude imaging condition uses the excitation time to judge the imaging time, and accordingly, we only need to store a small part of wavefield, such as the wavefield data of dozens of time points, the instances prove that they can even be imaged by only two time points. The traditional RTM usually needs to store the wavefield data of thousands of time points, compared with which the data storage can be reduced by tens or even thousands of times. Secondly, the RTM based on the random boundary uses the idea that the wavefield scatters rather than reflects in a random medium to reconstruct the wavefield source and thereby directly avoid storing the forward wavefield data. Numerical examples show that compared with other migration algorithms and the traditional RTM, both methods can effectively reduce wavefield data storage as well as improve data-processing efficiency while ensuring imaging accuracy, thereby providing the means for high-efficiency and high-precision imaging of fractures and caves by boreholes.

中文翻译：

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反射声波测井逆时偏移中的波场存储策略优化

本文针对反射声波测井中的逆时偏移成像技术，讨论了波场存储的优化策略，同时考虑了RTM本身的海浪数据存储问题。为此，提出并实施了两种优化方法来避免波场存储。首先，基于激发振幅成像条件的RTM利用激发时间来判断成像时间，因此，我们只需要存储一小部分波场，例如几十个时间点的波场数据，实例证明甚至可以仅在两个时间点对它们进行成像。传统的RTM通常需要存储数千个时间点的波场数据，相比之下，数据存储量可以减少数十甚至数千倍。其次，基于随机边界的RTM使用波场散射而不是在随机介质中反射的思想来重构波场源，从而直接避免存储正向波场数据。数值算例表明，与其他偏移算法和传统的RTM方法相比，两种方法均能有效减少波场数据的存储量，并在保证成像精度的同时提高数据处理效率，从而为裂缝的高效高精度成像提供了手段。和由钻孔洞。