Validation and standardization of asphaltene deposition by capillary experiments

Abstract

Asphaltene deposition can occur during processing and production of crude oil and can cause severe problems for the oil industry. In this experiment, n-heptane was used as a precipitant to destabilize asphaltenes to force deposition inside a capillary. From previous studies, the asphaltene deposition mechanism is still unknown and reproducibility has not been thoroughly investigated. The deposition apparatus has been developen to improve good mixing by adding a connection line and mixing frit before the solution flows into the capillary. A pre-filter was also added to prevent asphaltenes formed in the mixing section from travelling into the capillary. The modified apparatus shows more consistent results. Initial results have shown that asphaltenes will deposit well below the onset point. These experiments were performed with oil that had a relatively high asphaltene content. In the field, asphaltene deposition problems can occur with a variety of asphaltene contents. We have exphaded our investigation to study an additional crude oil. We also investigated the properties affection the asphaltene deposition for each oil studied.