A high-resolution method for processing coal measures seismic data based on anisotropic medium theories and its application

Objective The increasing importance of the exploration and exploitation of deep resources poses new requirements for high-precision seismic exploration. Given that conventional isotropy-based data processing methods are no longer applicable to the coal-bearing strata with strong anisotropy. Methods This study proposed a method for processing seismic data based on theories of both transverse isotropy medium with a vertical symmetry axis (VTI) media and transverse isotropy with a horizontal axis of symmetry (HTI) media. First, to characterize the depositional characteristics of coal-bearing strata, this study analyzed the features of VTI media, revealing that high-order dynamic correction can effectively eliminate anisotropy-induced event bending in large-offset seismic data, thus ensuring that the common reflection points in both far and near channels can be in-phase and improving the data stacking and imaging quality. Second, targeting the characteristics of tectonic fissures, this study relied on the azimuthal anisotropy analysis of HTI media. Specifically, using Offset-Vector Tiles (OVT) domain processing, the influence of varying azimuthal differences on data was removed by establishing the parameter fields of azimuthal anisotropy. Using both methods, this study developed a practical processing and correction method suitable for target strata with anisotropy by establishing a rational process and choosing optimal key parameters. This method can achieve effective velocity analysis and data stacking of coal-bearing strata under complex conditions, thus improving the resolution and interpretation accuracy of coal measures seismic data. Results and Conclusions The application results indicate that the new method can obtain seismic data with higher dominant frequency and a wider frequency band and is more advantageous in identifying the features of small structures and characterizing paleogeographic environments, thereby providing strong support for the fine-scale geological interpretation. This study highlighted the necessity of the processing of anisotropy for coal-bearing strata, potentially promoting the applications of anisotropy processing techniques in wide-azimuth seismic explorations.