Seismic attributes correlated with incised valley thickness in recent stratigraphy of the Sunda Shelf, Indonesia

摘要

Many attributes can be extracted from seismic data, but identifying which are useful for mapping channelized deposit character (planform, depth, edges, internal architecture, lithology, etc.) is a long-standing challenge for petroleum workers and a future challenge for groundwater workers. A high-quality, large (3,154-km~2; 1,218 mi~2) 3D seismic data volume collected in a highly channelized stratigraphic series found in the upper 500 ms of the Sunda Shelf in offshore Indonesia was used to map incised valley development on this shelf. Defined on a seismic grid at 25-m (82-ft) spacing, ten valley bases were then exported to ArcGIS, which was used to define each valley's thalweg. Valley-base elevation and several seismic attributes were then extracted along each thalweg. Resulting correlations and relationships could be used to infer thickness variability and reservoir characteristics of channelized deposits from 2D planform analysis and profiling. Two seismic attributes are somewhat correlated with alongvalley thicknesses collectively across the ten valleys: coherency (r = -0.40) and 30-Hz component amplitude (r = 0.34). Instantaneous frequency, reflection strength, and average absolute amplitude exhibit negligible correlation with thickness (|r|<0.06).