Improving Seismic Imaging in Complex Geologies Using TLFWI with Better Land Acquisition

Seismic imaging in the Sureste Basin, located in the southeastern Gulf of Mexico, presents significant challenges due to complex subsurface conditions and the limited effectiveness of conventional techniques. These difficulties arise from a combination of near- surface heterogeneity, irregular onshore topography, and a geologically diverse subsurface. The shallow Cenozoic section is dominated by extensional features, while deeper Mesozoic intervals transition into compressional domains. Velocity modeling is further complicated by the presence of salt bodies, over-pressure shale diapirs, rafted Mesozoic sections, and carbonate-rich layers (Figure 1). Across the Sureste Basin and in the broader Gulf of Mexico, velocity model building is constrained by poor illumination, high noise levels, and wavefield distortions introduced by salt and over-pressured shale. Inaccurate shallow velocity models result in distorted moveouts and incoherent gathers, which are unreliable for tomographic updates. Moreover, model building methods based on interpreted horizons and primary reflections are inherently limited by the quality of the underlying image. In areas where imaging is degraded— particularly at depth—interpretation-driven velocity refinements become highly uncertain (Figure 1). Legacy images and models in this region illustrate a range of geological complexities. On the right side of the section, thick and laterally extensive shale bodies in the shallow subsurface obscure the deeper Mesozoic targets. The central portion contains a rafted and strongly compressed Mesozoic block, leading to intense structural deformation. On the far left, a large salt body with multiple diapirs overlays Jurassic sediments, causing further wavefield distortion and imaging difficulty.