Analysis on Improving Time-Depth Conversion Accuracy via 3D Geological Modeling

3D geological modeling serves as a core component of geological research during hydrocarbon reservoir development and represents the ultimate outcome of reservoir characterization. Its accuracy largely depends on the richness and reliability of available data. For reservoirs in the early development stage—characterized by sparse well points and complex structures—maximizing the utilization of effective information from known data is essential for constructing geological models during preliminary evaluations. Time-depth conversion, a critical step in structural interpretation of seismic data, involves transforming processed seismic data from the time domain to the depth domain. This study employs Synthetic seismic record for time-depth conversion and utilizes velocity spectra to establish a velocity model for inter-well auxiliary conversion, ensuring high precision at both well locations and inter-well regions. For mid-to-shallow layers such as the Fuyang reservoir, where reflections are distinct and layers exhibit strong continuity,Synthetic seismic record are applied for time-depth conversion at well points, while random interpolation suffices for inter-well regions to meet modeling accuracy requirements. In areas with sparse well patterns or deep volcanic rock formations—where inter-well distances are large, layer continuity is poor, and significant discrepancies exist between well points and inter-well regions—the combined use of Synthetic seismic record and velocity spectra to construct a velocity model achieves the necessary precision.