Comparison of petrophysical rock types from core and well‐logs using post‐stack 3D seismic data: Field example from Maracaibo‐Venezuela

Abstract

A well log based reservoir study together with post stack 3D seismic data analysis was used to assess the petrophysical rock type distribution in an area located on the West side of Lake Maracaibo-Venezuela. The calculated petrophysical rock types were obtained using the Windland R35 (Gunter, et al, 1997) equation which includes information collected from core data: pore throat size distribution, porosity, and permeability. Permeability and rock type curves at the non-cored wells were predicted using available core data. Several consistency checks and quality control revisions were applied to obtain the results from these predictions in order to have a reliable relationship between petrophysical properties and petrophysical rock types. The resulting curves at the depth interval of interest were correlated throughout the field and calibrated with 3D seismic data. In order to obtain the correct parameter to enhance spatial rock type distribution, seismic attribute analysis was performed and a well log vs. seismic attribute cross-plot relationship was established to predict petrophysical rock properties in the interval. The predicted petrophysical rock type map provides extremely valuable constraints for the development of the field. The results clearly indicate that the application of this workflow is valuable for determining new locations to be drilled either for production or injection.