An Investigation of Asphaltene Precipitation During Natural Production and the CO2 Injection Process

作者：Ashoori S^*; Balavi A

来源：Petroleum Science and Technology, 2014, 32(11): 1283-1290.

DOI：10.1080/10916466.2011.633590

• fugacity verification
• asphaltene precipitation
• CO2 injection
• gravimetric method
• solid model

Some of Iranian oil reservoirs suffer from operational problems due to asphaltene precipitation during natural depletion, so widely investigation on asphaltene precipitation is necessary for these reservoirs. In this study, a reservoir that is candidate for CO2 gas injection process is selected to investigate asphaltene precipitation with and without CO2 injection. In this case, asphaltene precipitation is monitored at various pressures and reservoir temperature. Then, a series of experiments are carried out to evaluate the amount of precipitated asphaltene by injection different molar concentrations (25%, 50%, and 75%) of CO2. The results show that during primary depletion the amount of precipitated asphaltene increases with pressure reduction until bubble point pressure. Below the bubble point the process is reversed (i.e., the amount of precipitated asphaltene at bubble point pressure is maximum). The behavior of asphaltene precipitation versus pressure for different concentrations of CO2 is similar to primary depletion. Asphaltene precipitation increases with CO2 concentration at each pressure step. In the modeling part, solid model and Peng-Robinson equation of state are employed which show a good match with experimental results.

• 出版日期2014-6-3
• 单位中国石油大学（北京）