Experimental Study of Asphaltene Precipitation Behavior During Miscible Carbon Dioxide Injection

A. Alizadeh, H. Nakhli, Riyaz Kharrat, M. H. Ghazanfari, M. Aghajani

Research output: Contribution to journalArticleResearchpeer-review

2 Citations (Scopus)

Abstract

Many reservoir and production engineers face asphaltene precipitation as a major problem during miscible carbon dioxide flooding projects. Experimental studies regarding asphaltene precipitation are therefore employed to assist in selecting appropriate facilities and proper operation schemes. During this study, a series of high pressure, high temperature experiments are designed and performed to analyze asphaltene precipitation behavior of an Iranian light reservoir crude at reservoir conditions due to natural production and miscible CO2 gas injection. For both sets of experiments, two different temperature levels (including reservoir temperature) are selected to investigate the role of temperature on asphaltene precipitation as well. Results of natural production experiments indicate that the maximum amount of precipitation occurs at reservoir bubble point pressure, while for each specified pressure asphaltene precipitation increases as the temperature is raised for the whole range of pressures. Carbon dioxide injection experiments, however, have terminated in some remarkable findings: for small CO2 concentrations, CO2 behaves as a hindering agent and lowers the amount of precipitation; on the contrary, for higher fractions (values larger than critical CO2 concentration), the injection of CO2 results in more asphaltene precipitation. An increase in temperature during CO 2 injection results in (1) the increase of asphaltene precipitation, (2) the shift of the critical CO2 concentration to lower values, and (3) the decrease of the rate of asphaltene precipitation with CO2 concentration.
Original languageEnglish
Pages (from-to)1523-1530
Number of pages8
JournalEnergy Sources, Part A: Recovery, Utilization and Environmental Effects
Volume36.2014
Issue number14
DOIs
Publication statusPublished - 14 Apr 2014
Externally publishedYes

Keywords

  • asphaltene precipitation
  • carbon dioxide
  • EOR
  • miscible injection
  • temperature effect

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