TITLE:
Seismic Forward Modeling of the Lower Ordovician in the Northwestern Sichuan Basin
AUTHORS:
Mingxia Yan, Hongliang Wang
KEYWORDS:
Seismic Forward Modeling, Mixed Sedimentation, Model, Ordovician System
JOURNAL NAME:
Journal of Geoscience and Environment Protection,
Vol.14 No.1,
January
9,
2026
ABSTRACT: The Ordovician strata in the northwestern Sichuan Basin comprise a mixed sedimentary succession of clastic and carbonate rocks, the primary target strata are thin and exhibit significant variations in seismic reflections, complicating the interpretation of seismic strata. Consequently, precise well-to-seismic calibration is essential for accurately understanding stratigraphic architecture. Utilizing well logging, mud logging and seismic data from the Ordovician in this region, this study establishes geological models for various stratum interfaces within the mixed sedimentary sequence. Lithological seismic wave velocities are derived through logging analysis, leading to the establishment of a velocity model. Seismic forward modeling was then conducted to elucidate the seismic reflection characteristics and lateral variation responses of stratum interfaces under different lithological and thickness conditions. The findings indicate that the seismic response evolves from a double-peak to a composite wave and ultimately to a single peak as the stratigraphic thickness decreases. Moreover, an increase in the dominant frequency of seismic waves enhances the identification accuracy of thin layers. Specifically, frequencies below 15 Hz are insufficient to resolve layers thinner than 6 meters in the study area. The seismic forward modeling results provide a robust basis for seismic horizon interpretation and enhanced geological understanding in the study area.