Mohammad Ali Karambeigi - Department of Chemical and Petroleum Engineering, Science and Research Branch, Islamic Azad University, Tehran, Iran.
Riyaz Kharrat - Petroleum University of Technology, Tehran, Iran.

Precipitation of asphaltenes in reservoirs, wells and facilities has a severe detrimental effect on the economics of oil production because of a reduction in well productivity and/or clogging of the production facilities. Several procedures are used to remove or prevent asphaltene precipitation, but the uses of asphaltene inhibitors provide most practical and economical solution for deposits treatment. It is necessary to know the performance of an inhibitor before its application in the field. In this work performance of five non-commercial inhibitors; namely Benzoic Acid, Nonylphenol, Phenanthrene, Phthalic Acid, Salicylic Acid and one commercial inhibitor namely IR95 in the amount of precipitated asphaltene at standard condition, reservoir condition and occurring onset shifting have been studied. Results of inhibitor tests reveal that among non-commercial inhibitors, salicylic acid with having extra hydroxyl group (-OH) on Benzoic ring has the most effect on asphaltene precipitation reduction

Asphaltene, Precipitation, Inhibitor, Standard Condition, Reservoir Condition, Onset Shift