Velocity Modeling
 

Velocity modeling is a key part of most imaging projects, especially those in which seismic data will be migrated into the depth domain (PreSDM). Bulwark ION's GX Technology (GXT) is a leader in complex velocity model building and analysis.

Bulwark/GXT has developed a proven suite of pre-stack velocity analysis and model-building tools that can be combined, as needed, to obtain the best possible velocity model for each project. Methods of velocity estimation include tomography, gather-flattening and gather-fitting techniques. Bulwark/GXT has experience in working with seismic data from all major acquisition domains, including narrow azimuth marine, wide/complex azimuth marine, land, transition zone, and full-wave data. Each domain takes a dedicated approach to velocity model building, and Bulwark/GXT has both methods and tools to address each imaging challenge. All our migration algorithms output gathers that can be used in tomography, and range from simple CDP gathers to complex offset vector tiled gathers. Our tomographic engine has undergone continuous improvement to give optimal results with these various types of inputs. In addition to the tomographic approach, Bulwark/GXT also supports a full suite of structural tools to support this time of horizon based model building.
 

Velocity models may be built layered or non-layered, depending on the geologic complexity. The choice of layered or non-layered tomography is often geology dependent. The layer-based approach is generally used in areas where stratigraphic sequence layering is predominant. Non-layered tomography is applied in compacted environments or poorly illuminated areas where picking layers to identify velocity boundaries is difficult.

Bulwark/GXT tools are designed with versatility in mind, allowing the user to build a variety of complicated velocity models, including faulted blocks, lenses, and overhanging salt bodies. The vast majority of Bulwark/GXT's modeling tools incorporate proprietary editing, auto-picking, and QC features to speed the interpretation process.