The Influence Of Asphaltenes And Wax On The Foaming Properties Of CO₂ Flooding Oil In Gathering System

In some CO₂ flooding oilfields,the crude oil tend to foam strongly from the wellbore to the separator.These foams not only seriously affect the separator's efficiency,but also cause production accidents in severe cases.Therefore,it is of great significance to study the foaming behavior of CO₂ flooding crude oil in order to ensure safe production and efficient operation of the gathering system.At present,commonly used methods for the study of foam properties include Bikerman method and Waring Blender method.However,these methods are based on the normal pressure and have a difference between the depressure flow in the gathering system.To resolve this problem,the author designed a set of equipment,which can control the temperature and pressure precisely,to simulate the depressure flow of CO₂ flooding crude oil from the gathering pipeline to the separator.In view of the difficulty in obtaining a variety of crude oil samples with different asphaltenes and wax content,and also because the crude oil composition is too complex,the authors confect a series of synthetic oils with different asphaltene and wax content.The influence of asphaltene and wax on the foaming properties of synthetic oil was studied in the self-designed equipment,and analyzed the foam properties from the perspectives of foambility and stability.The results show that:?1?Asphaltene can enhance the stability of the foam generated by the synthetic oil;?2?When the asphaltene concentration is less than 0.2%,the foaming ability of the synthetic oil increases with increasing asphaltene concentration,and is higher than or when it is equal to this value,the asphaltene will inhibit the foambility;?3?The effect of the wax on the foaming property is reflected by the viscosity.As the viscosity increases,the synthetic oil foaming ability decreases but the stability increases...