Abstract：
In the fi elds of reservoir fracture prediction and fracturing monitoring, shear-wave splitting analysis has exhibited notable technical advantages. Compared with compressional waves, it offers a more robust capability for predicting the orientation and extent of fracture development systems or formation heterogeneity. In regions characterized by vertically or unidirectionally fractured thin interbedded formations, conventional shear-wave splitting analysis and correction methods based on the HTI (Horizontal Transverse Isotropy) medium model are inadequate. These methods fail to account for the increased propagation time difference between fast and slow shear-waves as they accumulate through layered media. This limitation arises because the subsurface medium in such scenarios is more accurately approximated by an orthotropic medium model. To address this challenge, shear-wave splitting analysis and correction methods based on orthotropic media have been developed and implemented. The method first determines the fracture orientation using established techniques, then separates the fast and slow shear-waves through wavefield rotation, and finally employs a matching algorithm to compute the instantaneous time diff erence between the fast and slow shear-waves. By introducing time-varying delay correction, this approach enables the accurate estimation of delay values that better refl ect the actual properties of the subsurface medium. As a result, it enhances the precision of fracture detection in targeted formation intervals. The method has demonstrated excellent performance in both synthetic model and real-data applications.
2025, Vol. 22 
