Abstract: To solve the serious asphaltene deposition problem of Xinjiang heavy crude oil，two new oil-soluble asphaltene dispersants were designed and synthesized with polyisobutylene succinic anhydride, aniline, aminophenol. The inhibitory effect of the obtained dispersants on asphaltene deposition was evaluated by spectrophotometry and microscope methods. The results show that the asphaltene dispersant PA2 which has a phenolic hydroxyl head group performs better than PA1 which has a phenyl head group. The optimum reaction conditions of PA2 are obtained as follows: 1.2:1 of n(p-aminophenol): n(polyisobutylene succinic anhydride), 120 ℃ of reaction temperature and 6 hours of reaction time．When the dosage of PA2 dispersant is 200 mg/L, the asphaltenes flocculation onset of Xinjiang heavy crude oil can be increased from -19.87 to 8.63.

Key words: heavy crude oil, asphaltene, precipitation, flocculation onset, dispersants