Adsorption of Carboxylates on Calcite: the Coupled Effect of Calcite–Brine and Brine–Oil Interactions

The adsorption of polar organic molecules on the surface brine-saturated carbonate rocks alters relative mobility oil and water with important implications for production groundwater remediation. We propose a mathematical model acid groups (initially contained in an phase) calcite presence brine. reduce problem into smaller subsystems characterize them by identifying key interactions. Oil–brine equilibrium is dictated partitioning acidic components between two phases. dissolved acids ionize to carboxylate species phase, which may either form complexes or precipitate as calcium salts binding ions from solution. All these interactions are implemented Phreeqc kinetic processes. To obtain main parameters (e.g., partition, ionization, constants) governing behavior different at chemical conditions, we tune sub-models relevant experimental data partitioning, precipitation, adsorption, electrokinetic measurements). then assess performance coupling reaction network transport equations simulating crude injection within chalk core predict effluent concentration history. By defining total acidity mixture several carboxylic acids, our satisfactorily fits data. number that commonly reported sole indicator does not allow distinguishing types nor their affinity toward surface. More sophisticated analytical methods quantifying required more accurate description process using model.