Response characteristics of shear waves scattered by fractures with borehole observation system

作者：Peng Liu, Huajun Fan, M. Zhang, Zhen Li, Jingwei Jiang, Yuan Gao, Kewen Wang · 发表于：Petroleum Science · 年份：2025 · DOI：10.1016/j.petsci.2025.03.004 · 被引用次数：6 · 研究领域：Seismic Imaging and Inversion Techniques、Geophysical Methods and Applications、Hydraulic Fracturing and Reservoir Analysis

Fractures play a crucial role in various fields such as hydrocarbon exploration, groundwater resources management, and earthquake research. The determination of fracture location and the estimation of parameters such as fracture length and dip angle are the focus of geophysical work. In borehole observation system, the short distance between fractures and detectors leads to weak attenuation of elastic wave energy, and high-frequency source makes it easier to identify small-scale fractures. Compared to traditional monopole logging methods, dipole logging method has advantage of exciting pure shear waves sensitive to fractures, so its application is becoming increasingly widespread. However, since the reflected shear waves and scattered shear waves of fractures correspond to different fracture properties, how to distinguish and analyze these two kinds of waves is crucial for accurately characterizing the fracture parameters. To address this issue, numerical simulation of wave responses by a single fracture near a borehole in rock formation is performed, and the generation mechanism and characteristics of shear waves scattered by fractures are investigated. It is found that when the dip angle of the fracture surpasses a critical threshold, the S-wave will propagate to both endpoints of the fracture and generate scattered S-waves, resulting in two distinct scattered wave packets on the received waveform. When the polarization direction of the acoustic source is parallel to the st...