Effect of Porosity on Elastic Moduli in Reservoir Zone of South Pars Field

The purpose of this study is to calculate and investigate the effect of porosity on the elastic moduli in Kangan and Dalan Formations in the South Pars gas field of Iran. Compressional and shear wave velocities were calculated using travel times of compressional wave and travel times of shear waves, which are deduced from the Dipole Shear Sonic Imager (DSI) logs. Bulk modulus, Shear modulus, Young’s modulus, Lame parameter, Poisson’s ratio and the ratio of K/G were calculated using the relationship between the acoustic wave velocities, density and physical moduli. In this study, the relationship between porosity and elastic moduli were determined by real data and observed that elastic moduli are decreased by porosity increasing. Comparison of elastic moduli with porosity shows significant consistency between bulk modulus and porosity (compared to other moduli). Also, the ratios of Vp/Vs, K/G and Poisson’s ratio were examined. Result of this investigation showed that these ratios are slightly reduced by increasing the porosity.