Prediction of Berea sandstone’s compressive strength from Brazilian tensile measurements: Effect of monovalent aqueous solutions

This study provides experimental correlations for estimating the compressive strength of Berea sandstone, both in its natural state and when altered by water and ion exchange, utilizing Brazilian tensile strength measurements. This was accomplished by introducing an experimental conversion factor that translates Brazilian tensile strength measurements into compressive strengths, thereby eliminating the necessity for expensive, complex, and time-intensive compression testing. The study demonstrated that the measured compressive strengths obtained through compression testing, along with the estimated compressive strengths derived from developed correlations, for over 100 specimens, are in close agreement. The impact of monovalent ionic solutions on the tensile and compressive strength of Berea sandstone was also examined using NaCl and KCl solutions at various concentrations. Results showed that both NaCl and KCl caused a noticeable reduction in both compressive and tensile strengths of Berea sandstone as compared to its native strength. Furthermore, it was found that the reduction in strength was closely correlated with the increase in ionic concentration, with the potassium ion demonstrating a less detrimental effect compared to the sodium ion. The findings of this study strongly advocate for considering the effects of ionic solutions included in drilling muds and fracturing fluids to acquire a more accurate assessment of compressive and tensile strengths, which is essential for wellbore stability and hydraulic fracturing designs. • Correlations between Brazilian tensile and compressive strengths have been developed for Berea sandstone in both its native state and in conditions altered by interactions with water and ions. • Disregarding the impact of interactions between ionic solutions and formation rocks may lead to an inaccurate evaluation of the mechanical integrity of these rocks. • Chemical osmosis, diffusion osmosis, and ionic diffusion can significantly influence the mechanical properties of rocks through the exchange of water and ions with surrounding aqueous solutions.