Criterion to foresee the affinity of various coatings/substrates to asphaltene deposition in oil wells

Asphaltene deposition in oil wells has long been considered a severe problem. It can be treated using various chemical, mechanical, and thermal methods. However, these methods are often associated with significant hazards, operational limitations, and costs. In light of these challenges, recent research has shifted towards preventive measures, particularly using surface coatings/substrates to inhibit asphaltene deposition. The present study introduces a novel criterion based on surface energy for assessing the effectiveness of such coatings/substrates. The criterion is derived using the XDLVO theory, which considers the adhesive interaction energy in an asphaltene/crude oil/surface system and its relation to the spreading coefficient. The approach provides a theoretical framework for understanding the interactions between asphaltenes, crude oil, surface coatings/substrates, and how these interactions influence asphaltene deposition. Subsequently, utilizing characterization data from ten surface coating/substrate samples, and corresponding crude oil and asphaltene samples from Z, K, and R fields, the accuracy of this criterion is evaluated. The results showed that, based on the proposed new criterion, among the selected coatings, L-80 and N-80 were asphaltene-repellent for oil Z-55 while SS316 and SS304 were repellent for oil K-42. For oil R-95, only the L-80 substrate exhibited affinity to asphaltene deposition, whereas other coatings were repellent. These results align well with field data, where 16% of wells in field Z, 43% in field R, and 100% in field K face asphaltene deposition.