Permeability prediction in tight gas reservoirs based on pore structure characteristics: A case study from South Western Iran

Abstract

Porosity, pore structure characteristics, and permeability are among the key petrophysical properties of shale gas resources. Accurate characterization of these parameters in the unconventional gas shale systems has been proved to be challenging due to the uniqueness of the pore structures, mineral compositions, tightness, and pores hosted in the organic matter. In this study, the porosity, pore structure characteristics, and permeability of cored samples from the Garau shale formation located in the southwestern part of Iran were evaluated using a combination of laboratory methods. Multiple linear regression analyses were then utilized to develop empirical relationships between helium permeability values, porosity, and pore throat radii. Results showed that the best permeability predictors for the examined samples could be developed using the pore throat radius that corresponds to a mercury saturation of 55% and porosity. This approach helps develop a permeability prediction model for tight shale gas reservoirs based on pore structure characteristics, reducing cost and time.

Keywords

• Shale gas
• Permeability
• Porosity
• Pore throat size
• Empirical relationships