Resolution sets the limit to the amount of stratigraphic information that can be extracted from seismic reflection data. To test the limit of vertical and spatial resolution of the seismic reflection method a late Jurassic (Kimmeridgian to Tithonian) interval was used as a “field laboratory” linking exposed 2D geology to nearby high-resolution 3D subsurface seismic data through shallow boreholes.
The studied interval is confined to six horizons of organic-rich, offshore marine shale interbedded with sharp-based shoreface sandstone bodies that have a potential as hydrocarbon reservoirs and play an important role in the stratigraphic analysis of basin fills. Quantification of the mechanical and geological properties, using over 400 core plugs, from outcrop and cores, along with continuous sonic logs, whole-core derived acoustic velocities and densities cover a wide spectrum of scales and frequencies provided the conversion of lithofacies and parasequences to mechanical stratigraphic units.
The resulting changes in mechanical properties still reflect the principal and intrinsic geological properties of the subsurface. Distinct changes in mechanical properties that are correlated to key sedimentological surfaces, like sequence boundaries, transgressive and regressive surfaces of marine erosion display a strong dependency on scale. Application of this mechanical stratigraphic modeling approach, may provide estimates of the upper limit of seismic resolution in ultra-high frequency shallow seismic data but may be adapted to resolve the maximum extraction of geological information from, lower frequency, wavelengths used in industry.