رضا آذین

Disulfide oil (DSO) is one of the byproducts of oil and gas refining processes, which is producedin the process of removing mercaptans and sweetening light hydrocarbons. This substance isusually yellow in color with a very pungent smell, penetrating and highly flammable, and itshigh concentration in the air causes anesthesia and dizziness. DSO consists of 17 different di-alkyl disulfides with alkane chains smaller than C4. Approximately 10 types of di-alkyl have been identified as the main components of DSO, which have the highest amount in thecomposition.Additive amounts of DSO were measured as 0.5, 1, 5, 10, and 20 wt% of crude oil to observe itseffect on the onset of asphaltene deposition. That the values of 5 and 20 wt% of DSO additivecould be more than 45% and about 50% respectively in reducing the onset of asphaltenedeposition, in cases where the crude oil is heavy, this additive can have an acceptableperformance. It should be noted that the efficiency of the 10 wt% additive in reducing deposit islower than 5 and 20 wt%, which is due to the phenomenon of self-aggregation of asphalteneparticles with the additive. By increasing the additive above 10 wt% in crude oil, this effect isneutralized and the higher amount of additive reduces the onset of deposition and prevents theformation of asphaltene deposition.A micromodel with a fracture design was used in these experiments, representing fracturedreservoirs. Effect of DSO with the optimal weight percentage of 5 wt% on asphaltene depositionwas visually investigated. It was also used as an organic base additive in the injection andoverharvest processes in the presence of MgCl2, CaCl2, NaCl salts and AOS and CTABsurfactants, and SiO2 and Fe3O4 nanoparticles in optimal weight percentages and aqueous base.These tests were done in three groups, the first group of tests is related to adding DSO to crudeoil and using 70 to 30 oil-water W/O emulsions containing salt, surfactant, and nanoparticles.The second group is the ad