能源环境保护2025，Vol.39Issue(6)：40-50,11.DOI:10.20078/j.eep.20250903
醇处理CO2对CO2与烷烃体系最小混相压力影响的实验研究
Effects of Alcohol-Treated CO2 on the Minimum Miscibility Pressure in CO2-Alkane Systems
摘要
Abstract
CO2-enhanced oil recovery(CO2-EOR)improves oil displacement efficiency and facilitates effective CO2 sequestration.However,in practice,the minimum miscibility pressure(MMP)between CO2 and crude oil often exceeds the formation's fracture pressure.Thus,reducing the MMP is critical for enhancing oil recovery efficiency.This study experimentally investigates how alcohol-treated CO2 affects the interfacial tension(IFT)and MMP in CO2-alkane systems.Initially,the effects of pressure and temperature on the IFT of the CO2-n-hexadecane system were systematically examined.Results show that,at constant temperature,IFT decreases with increasing pressure due to the enhanced solubility of CO2 in n-hexadecane.Below 3 MPa,IFT decreases with rising temperature,whereas above 3 MPa,it increases.This highlights that IFT is influenced by both temperature and CO2 solubility.Comparative analysis reveals that CO2-n-hexadecane systems exhibit consistently higher IFT than CO2-n-dodecane systems.This is attributed to the longer carbon chain and stronger intermolecular forces of n-hexadecane,which reduce its miscibility with CO2.Subsequently,the effect of alcohol-treated CO2 on IFT was assessed.In the high-pressure region(＞6 MPa),CO2 treated with ethanol or isopropanol significantly reduced IFT,while the effect was negligible at lower pressures.This behavior stems from increased CO2-alcohol solubility at high pressure,enhancing alcohol interaction at the interface and reducing IFT.The CO2-n-dodecane system treated with ethanol also demonstrated notable IFT reduction,with a progressive decrease as pressure increased.The absence of abrupt changes suggests a steady interface modification,facilitated by ethanol's high solubility in n-dodecane and the shorter carbon chain of n-dodecane,which promotes alcohol adsorption and alignment at the interface.Finally,MMPs of the CO2-n-hexadecane system under different treatments were determined via linear extrapolation.Alcohol-treated CO2 notably reduced MMP,especially at elevated temperatures.At 70℃,ethanol and isopropanol treatments reduced MMP by 20.16％and 24.28％,respectively,whereas at 100℃,the reductions were 13.74％and 22.67％.Isopropanol was more effective than ethanol,likely due to its longer hydrocarbon chain and stronger interfacial adsorption capacity.This study elucidates the mechanisms by which alcohol-treated CO2 interacts with alkane systems to reduce IFT and MMP,offering valuable experimental insights for optimizing CO2-EOR applications.关键词
CO2驱油/界面张力/最小混相压力/醇处理/CO2封存Key words
CO2-enhanced oil recovery(CO2-EOR)/Interfacial tension/Minimum miscibility pressure/Alcohol treatment/CO2 sequestration分类
资源环境引用本文复制引用
美合日阿依·穆太力普,闫乐乐,左凯帅,姚志远..醇处理CO2对CO2与烷烃体系最小混相压力影响的实验研究[J].能源环境保护,2025,39(6):40-50,11.基金项目
国家自然科学基金资助项目(52366010) （52366010）
新疆维吾尔自治区重点研发专项课题(2022B01033-2) （2022B01033-2）
"天山英才"计划——青年人才托举工程(2023TSYCQNTJ0035) （2023TSYCQNTJ0035）
