Multi-Wave Seismic Sedimentology in Geological Anomaly Characterization: Methodological Innovations and Case Applications

Juncheng Dai^1*Wenzheng Lv¹Wei Wei¹Yuanyuan Yan¹Bin Luo¹Qi Ran²Kang Chen¹Yifei Wang¹

• ¹Exploration and Development Research Institute, PetroChina Southwest Oil and Gasfield Company, Chengdu, China
• ²PetroChina Southwest Oil and Gasfield Company, Chengdu, China

With the increasing demand for unconventional resources, accurate characterization of tight sandstone gas reservoirs has become crucial. This study introduces an innovative multi-wave seismic sedimentology approach integrating P-wave, converted S-wave (PS-wave), and pseudo-S-wave attributes to enhance lithological prediction and reservoir heterogeneity analysis in the Jurassic Shaximiao Formation, Sichuan Basin. By combining 90 ° phase rotation, high-frequency stratal slicing, and differential PP-and PS-wave amplitude and phase analysis, the workflow effectively resolves vertically stacked sand bodies and identifies high-porosity "sweet spots." Results demonstrate that PS-wave data provide stable polarity responses for lithology discrimination, while pseudo-S-wave attributes improve vertical resolution for multi-phase channel identification. Field validations confirm >90% accuracy in sand body geometry predictions, with horizontal drilling achieving 87% reservoir encounter rates. The methodology overcomes limitations of conventional P-wave methods in low-impedance-contrast reservoirs and offers a cost-effective solution for early-phase exploration with limited well data. This integrated approach advances tight gas exploration by enabling robust characterization of complex geological anomalies and heterogeneous systems.