Seismic Velocity – Reservoir Permeability Relations within Hydraulic Units in an Oil Field Southwest Iran

Establishing a relation between permeability and velocity has met with little success so far. Different types of uncertainties usually make this relationship not very straightforward. Categorizing the pore systems in different hydraulic units may reduce the uncertainties. This study tries to improve characterization of a carbonate reservoir with complex pore systems which is located in southwest of Iran. A combination of classification methods was used to build a robust determination of Hydraulic Units using porosity and permeability values. Then the concept of grouping porosity and permeability data according to their FZI (Flow Zone Indicator) values were tested. It was shown that such relation can be extended to seismic parameters to create strong correlation between velocity and permeability. Strong correlation between P and S waves' velocity and permeability in this field was observed, i.e. the correlation coefficient for Vp-Permeability lies between 0.72-0.96 and for VS-Permeability lies between 0.62-9.98. Such a relation is invaluable as a prediction tool. We understood that by grouping rocks into hydraulic units, we can control and predict flow properties such as permeability via seismic velocity in this field.