TY - JOUR

T1 - Experimental Study of Asphaltene Precipitation Behavior During Miscible Carbon Dioxide Injection

AU - Alizadeh, A.

AU - Nakhli, H.

AU - Kharrat, Riyaz

AU - Ghazanfari, M. H.

AU - Aghajani, M.

PY - 2014/4/14

Y1 - 2014/4/14

N2 - 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.

AB - 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.

KW - asphaltene precipitation

KW - carbon dioxide

KW - EOR

KW - miscible injection

KW - temperature effect

UR - http://www.scopus.com/inward/record.url?scp=84901402957&partnerID=8YFLogxK

U2 - 10.1080/15567031003614672

DO - 10.1080/15567031003614672

M3 - Article

AN - SCOPUS:84901402957

VL - 36.2014

SP - 1523

EP - 1530

JO - Energy Sources, Part A: Recovery, Utilization and Environmental Effects

JF - Energy Sources, Part A: Recovery, Utilization and Environmental Effects

SN - 1556-7036

IS - 14

ER -