Deformation mechanics and acoustic propagation in reservoir rock under brine and oil saturation: An experimental study

Deep saline aquifers and depleted oil fields have been identified as two main potential geological sinks for CO₂ sequestration due to their preferable geological conditions. However, correct understanding of their in-situ chemicomechanical properties (prior to CO₂ injection) is necessary to evaluate their safe and long-term CO₂ storage potential. This study therefore investigated the effect of brine and oil saturations on the mechanical and acoustic properties of reservoir rock by performing a series of strength tests using acoustic emission technology. According to the test results, the mechanical responses of reservoir rocks vary with the saturation condition, and the existence of brine and oil in water-saturated reservoir rocks causes their mechanical properties to be noticeably enhanced.