One of the major problems in all area of petroleum industry, including production, operation,storage and transportation, is formation of heavy organic compounds, e.g., asphaltene and wax, and their consequent deposition in equipment and pipelines. Change in crude oil composition, temperature and pressure leads to asphaltene precipitation. Thus, it is of vital importance to determine onset of asphaltene precipitation during oil production. In this regard, various techniques have been suggested in literature, each with its own pros and cons. However, from practical point of view, one needs to decide which method serves to be proper one. To this end, present study gives a comprehensive critical review for different techniques serve to determine onset of asphaltene precipitation along with comparing their advantages and disadvantages. Since each method presents its own definition for onset, such as onset of precipitation, clustering and deposition; it is necessary to distinguish their difference based on underlying physical mechanisms. It was concluded that mechanism of asphaltene precipitation for determining onset of asphaltene precipitation plays a substantial role.
