Joint imaging of 3D VSP PP and PS waves in the OVT domain

Joint PP- and PS-wave imaging employs multicomponent data for precise strata characterization. Registering PS waves to the PP time domain is essential; however, it introduces wavelet distortions, which can be avoided by direct PP–PS imaging in the PP domain. Three-dimensional (3D) vertical seismic profiling (VSP) provides high-resolution wavefield information and accurate PP–PS correspondence; however, wide-azimuth acquisition can generate notable zero-offset travel-time (t₀) anomalies caused by azimuthal anisotropy in common image gathers (CIGs), reducing resolution. In this study, we present a field-data-based workflow for offset vector tile (OVT) pre-stack time migration of 3D VSP PP and PS waves in the PP t₀ domain. We established criteria for dividing source–image point orientation sectors to migrate 3D VSP data in the OVT domain, generated initial CIGs using velocities derived from first breaks for each orientation, iteratively refined migration velocities, and eliminated t₀ anomalies caused by azimuthal anisotropy. After establishing an accurate PP–PS mapping relationship in PP t₀ using the updated VP/VS, we validated the final PP and PS sections against corridor stacks. Consistent alignment and strong correlations with corridor-stack data confirmed workflow reliability. Field application of our method demonstrated its effectiveness for correcting CIG anisotropy, indicating significant potential for VSP exploration.