Asphaltene precipitation and deposition in porous media damages formation by reducing permeability and altering wettability, resulting in a significant reduction in reservoir oil production. Although the effects of some factors such as temperature, pressure, and composition have been studied over time, the effects of others, such as emulsified brine, remain uncertain and the available data in this area is limited. Most importantly, the effect of brine injection on deposition has never been studied in previous research. In this study, a number of systematic experiments were designed and conducted to investigate the effect of the aqueous phase. Several variables, including the water content, salt type, and salt concentration were studied in both the static and dynamic systems, and the evidence of consistent changes in asphaltene precipitation and deposition has been obtained. The results revealed that when the water amount reaches 50 wt %, asphaltene precipitation increases close to 10 wt %. However, as the amount of water increased, the intensity of asphaltene precipitation decreased. Furthermore, various salts have shown different behaviors in the static system and dual effects have been observed with increasing concentration. The optimum concentration of different salts was found to be between 25 000 and 40 000 ppm, MgCl2 producing the most asphaltene precipitation and KCl producing the least. MgCl2 at a concentration of about 40 000 ppm resulted in the precipitation of 7.8 wt % asphaltene and while this was 6.4 wt % for KCl 25 000 ppm. Also, for these salt concentrations, the interfacial tension reached 20.5 and 22.5 mN/m, respectively. Although the presence of water in the flooding system reduced the permeability up to 60% by depositing the asphaltene, unlike the static test, the presence of salt had no significant effect on the permeability reduction.

No abstract