<p>The complex interactions between nanoparticles and ion behavior in subsurface water systems had crucial implications for understanding the dynamics of petroleum reservoirs. This study investigated the intricate relationship between ultra-dispersed particles of bentonite and conductivity changes in pore water. We examined the mechanisms underlying ion trapping by bentonite nanoparticles by utilizing both experimental methodologies, such as XRD (X-ray diffraction), TEM (transmission electron microscopy), ICP-OES (inductively coupled plasma optical emission spectroscopy), and Rw microcell, and computational simulations via COMSOL Multiphysics. Our results elucidated the fundamental processes at play and provided valuable insights for optimizing pore water analyses in the petroleum industry. Through a rigorous examination of experimental and simulated data, this paper sheds light on a comprehensive understanding of nanoparticle-mediated ion absorption and its impact on conductivity in subsurface water chemistry.</p>