algorithm

The static Young’s modulus (Esta) and the uniaxial compressive strength (UCS) are key parameters in the geomechanical study of hydrocarbon reservoirs. These parameters are typically estimated using empirical models that relate the strength and elastic parameters of the rock to their petrophysical properties. In the present research, the existing empirical models in the literature (specifically for carbonate rocks) were compiled and investigated, this was followed by performing experimental tests on 27 core samples to measure the porosity (n), the density (ρ), the compressive and shear wave velocities (Vp and Vs, respectively), Esta and UCS for a carbonate gas reservoir in the south of Iran. Next, particle swarm optimization (PSO) and regression analysis (RA) were conducted to develop estimator models for the Esta and UCS. Results of this study showed that the best models produced by the PSO algorithm were more accurate than not only the best models produced by the RA, but also the models proposed by previous researchers by 7% and 48%, respectively, for the Esta and by 10% and 7%, respectively, for the UCS. On this basis, it was strongly recommended to apply the empirical correlations developed through the PSO for more accurate estimation of the studied parameters across the investigated field and similar fields.