Innovative Near-Surface Model Building via Multi-Domain SJI: Insights from Onshore US

Summary The increasing complexity of land-based hydrocarbon exploration necessitates the development of high-fidelity, high-resolution 3D seismic imaging techniques. In many onshore environments, geological features such as buried karsts, paleochannels, and anthropogenic fill zones introduce rapid lateral velocity variations that can significantly distort seismic wave propagation. These distortions often manifest as mispositioned reflectors, imaging artifacts, and a general loss of resolution, complicating both structural and stratigraphic interpretation. This case study presents a depth reprocessing initiative aimed at addressing these challenges in a structurally complex onshore environment. The primary objectives were to suppress artificial imaging features introduced by near-surface heterogeneity and to enhance the visibility of subtle geological elements, including minor faulting and stratigraphic discontinuities that are critical for reservoir delineation. To overcome these limitations, a simultaneous joint inversion (SJI) of refracted and surface waves was implemented. This advanced technique integrates complementary wavefield information to produce a high-resolution near-surface velocity model. By jointly inverting both wave types, the method leverages the sensitivity of refracted waves to deeper velocity structures and the sensitivity of surface waves to shallow layers. By integrating these datasets, the inversion produced a geologically consistent and high-fidelity near-surface velocity model. The detailed near-surface model produced by SJI was then incorporated into the depth imaging workflow, significantly improving the accuracy of static corrections and the fidelity of the final seismic image. The results demonstrated a marked reduction in imaging artifacts, clearer delineation of fault systems, and enhanced visibility of subtle stratigraphic features that were previously obscured. This approach not only improved the overall quality of the seismic image but also increased interpreter confidence, supporting more informed decision-making in subsequent exploration and development phases.