Asphaltene-Induced Permeability Reduction in Micro- And Nanopores and Its Mitigation Using Hydrocarbon-Based Chemicals

Abstract This study investigates the behavior of asphaltene concentration under controlled filtration conditions and evaluates potential mitigation strategies using selected solvents. The experimental program was designed in two main stages. First, asphaltene-rich oil samples were subjected to filtration through membranes with pore sizes of 10 nm and 100 nm to examine the influence of pore restriction on asphaltene retention and transport. The filtration experiments were conducted under varying pressure and temperature conditions in order to simulate different reservoir scenarios and to assess how thermodynamic and flow parameters affect asphaltene stability and aggregation behavior. The results indicate that membrane pore size plays a critical role in governing asphaltene passage and accumulation. The 10 nm membrane demonstrated significantly higher retention of asphaltene particles, particularly under elevated pressure differentials, suggesting enhanced aggregation and mechanical trapping at smaller pore constrictions. In contrast, the 100 nm membrane allowed a greater fraction of dispersed asphaltene particles to pass, although deposition was still observed under certain pressure–temperature combinations. Increasing temperature generally improved asphaltene stability and reduced apparent deposition tendencies, while pressure variations influenced both precipitation onset and aggregate size distribution. These findings highlight the coupled effects of thermodynamic conditions and pore-scale confinement on asphaltene transport behavior. Following the filtration experiments, mitigation tests were performed to evaluate the effectiveness of different treatment fluids in removing or dissolving deposited asphaltenes. The used membranes were submerged for 48 hours in separate beakers containing water, xylene, kerosene, and heptane. This soaking approach allowed direct observation of solvent–asphaltene interactions over an extended contact period. Water showed minimal impact on asphaltene removal, confirming the hydrophobic nature of the deposits. In contrast, aromatic and hydrocarbon solvents demonstrated varying degrees of effectiveness. Xylene exhibited the highest dissolution capability, consistent with its strong solvency for heavy aromatic fractions. Kerosene and heptane showed moderate mitigation performance, with partial removal observed depending on the initial deposition severity. Overall, the combined filtration and mitigation results provide insight into how pore size, pressure, and temperature influence asphaltene accumulation, as well as how different solvents perform in restoring permeability at the nanoscale. These findings contribute to a better understanding of asphaltene-related formation damage and potential remediation strategies.