Seismic Interpretation of Carbonate Reservoirs Using Rock Physics Modeling

This paper addresses the challenges in estimating porosity, dolomite content, and pore fluid type in carbonate reservoirs from seismic data due to the stiffness of the rock, complex pore networks and the limitations of post-stack seismic data. To overcome these, we developed a seismic interpretation workflow integrating rock physics models and geologic site-specific relationships. Using wireline data from a carbonate reservoir that is mainly composed of calcite and dolomite, we performed rock physics diagnostics and developed a Stiff-Sand rock physics model that accurately models that elastic properties of the rock.

The workflow uses only acoustic impedance cut-offs and a look-up table to match porosity-dolomite pairs with impedance values. Additionally, hydrocarbon presence is inferred from stiffer intervals with medium to high dolomite content. Applying the workflow to low-frequency seismic data showed promising results in predicting porosity, dolomite content, and pore fluid type.