Optimizing the wavefi eld storage strategy in refl ection-acoustic logging reverse-time migration*
Li Yu-Sheng, Li Ning, Yuan ye, Wu Hong-Liang, Feng Zhou, and Liu Peng
1. School of Earth and Space Sciences, Peking University, Beijing 100871, China.
2. PetroChina Research Institute of Petroleum Exploration and Development, Beijing 100083, China.
Abstract 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 highprecision imaging of fractures and caves by boreholes.
This work was supported by CNPC scientifi c research and technology development projects (No. 2016A-3605).
Corresponding Authors: Li Yu-Sheng (Email: lysgeophysicis@163.com)
E-mail: lysgeophysics@163.com
About author: Li Yu-Sheng, he got his bachelor degree in geophysics in 2013 and his master degree in earth exploration and information technology in 2016 from China university of petroleum (east China). Now he is a PHD student of School of Earth and Space Sciences, Peking University. His main research interest is seismic data processing and reflection acoustic logging data processing. Email: lysgeophysic@163.com.
Cite this article:
. Optimizing the wavefi eld storage strategy in refl ection-acoustic logging reverse-time migration*[J]. APPLIED GEOPHYSICS, 2019, 16(4): 537-544.
2019, Vol. 16 
