Marmousi2-Res: Multi-Saturation Resistivity Extension to the Marmousi2 Model

Marmousi2-Res is a resistivity companion to the Marmousi2 elastic benchmark, derived from its elastic properties using Gassmann fluid substitution and Archie's law. The model is classified into seven lithologies at the pixel level, and porosity is recovered for all ten hydrocarbon zones by back-calculating from the Gassmann equation and the density relation. Resistivity is calculated from Archie's equation using temperature-corrected brine resistivity from the Arps relation. The release provides resistivity grids for six uniform water saturations (Sw = 15% to 100%) and two split-saturation scenarios with distinct gas- and oil-zone saturations. The mean P-wave velocity error after round-trip fluid substitution is 4 m/s (<0.4%), and the recovered matrix density is constrained to 2.56-2.62 g/cm3. Averaged over all zones, resistivity is approximately 263 times more sensitive than P-wave velocity to a saturation change from 30% to 70% hydrocarbon saturation. One-dimensional CSEM modelling shows that reservoirs buried 600-1600 m below the seafloor are detectable with standard marine CSEM acquisition, while the deepest zones at approximately 2500 m are marginally detectable at low frequency. This archive contains the pixel-level lithology classification, hydrocarbon-zone masks, resistivity grids for all saturation scenarios, rock-physics tables, and all scripts required to reproduce the workflow, including the 1D CSEM detectability analysis. Licensing. The Python source code is released under the MIT License. The generated data products are released under the Creative Commons Attribution 4.0 International License (CC BY 4.0). The bundled Dipole1D forward-modelling code (Key, 2009), located in scripts/csem_detectability/dipole1d, is redistributed under its own GPL-3 license; see the COPYING file in that directory. This archive supports the article published in Applied Computing and Geosciences (Elsevier).