Experimental Study of Asphaltene Deposition:Short Review

Abstract

Asphaltenes are always present in crude oils, their instable form in oil could cause some problems. The asphaltene instability occurs due to variations in the pressure, temperature and composition. When asphaltene instability arises in oil, it deposits in the oil production, transportation, and processing stream. Finding the accurate place of this instability in oil pipes and reservoirs is of the most important. It should be mentioned that, the instability is not always considered as the prerequisite to create deposit in flow lines, because asphaltene flocs are carried out by the oil flow so they make no deposit. Therefore, assessing the behavior of asphaltene deposits in flow systems is necessary.To improve understanding and, hence, prediction of asphaltene deposition, several tests have been reported. Accordingly, asphaltene deposit in steel pipes with large diameter, capillary tubes, beds and Taylor-Couette cells can be mentioned. A capillary deposition test in long stainless steel capillaries has been used to investigate the tendency of a wide variety of oils to create deposits. In the capillary tube test, the measurement of pressure variations along the tube is utilized to assess the amount of deposit its. Findings of this section have been used to simulate asphaltene behavior in the reservoir porous media. Other tests have used pipe circular and a Taylor−Couette cell. They measure the amount of deposit indirectly by measuring temperature in different parts of the system. And their data are being used to develop simulators to predict the rate of growth of arterial asphaltene deposits under wellbore conditions.