Adsorption Mechanism of Elemental Sulfur in High-Sulfur Gas Reservoirs Based on Molecular Simulation and Monte Carlo Methods

Elemental sulfur deposition in sulfur-bearing gas fields can disrupt gas well production and create safety risks, making it essential to understand its deposition mechanisms. While previous studies have examined sulfur adsorption on single minerals, the behavior in carbonate mixed minerals remains unclear. This study uses molecular simulations to investigate elemental sulfur adsorption in calcite–dolomite mixed slit models. Results show that, at the same slit size, sulfur adsorption increases with pressure and temperature, with adsorption amounts ranging from 5.95 × 10−5 to 1.08 × 10−2 mg/m2. Pressure has little effect on adsorption heat, whereas higher temperatures reduce it. At equilibrium, sulfur molecules preferentially adsorb on calcite. Increasing pressure raises sulfur adsorption on calcite, while higher temperatures enhance adsorption on both mineral surfaces. Compared with single-mineral slits, competitive adsorption in mixed systems leads to a less uniform sulfur distribution on calcite. These findings provide theoretical insights into sulfur deposition mechanisms and prevention strategies for high-sulfur gas reservoirs.