选取正二十烷、正二十四烷、正二十八烷、正三十二烷4种C16+重质正构烷烃,分别与CO2组成二元体系,通过系列恒质膨胀实验,获取各体系的泡点压力,分析了重质正构烷烃-CO2体系的相变边界变化规律及其机理。研究表明,重质正构烷烃-CO2体系的泡点压力随CO2含量的增加大幅度升高,随温度升高呈直线增大趋势。CO2摩尔分数小于等于50%时,重质正构烷烃-CO2体系的泡点压力随碳数增加略有下降,且CO2摩尔分数越大降幅越大;CO2摩尔分数等于75%时,重质正构烷烃-CO2体系泡点压力随碳数增加略有增加。CO2含量小于等于50%时,随烷烃碳原子数的增加,体系的泡点压力受温度变化的影响减小;CO2含量等于75%时,随烷烃碳原子数的增加,重质正构烷烃-CO2体系泡点压力受温度变化的影响基本不变。从微观尺度分析,重质正构烷烃-CO2体系相变边界呈上述变化规律的原因在于重质正构烷烃分子链较长,分子间间隙较大,容纳CO2分子的能力较强,且易发生蜷曲。图7表1参16
刘晓蕾
,
秦积舜
,
韩海水
,
李实
,
姬泽敏
. C16+正构烷烃-二氧化碳体系的相变边界变化规律[J]. 石油勘探与开发, 2017
, 44(1)
: 104
-109
.
DOI: 10.11698/PED.2017.01.12
N-eicosane, N-tetracosane, N-octacosane and N-dotriacontane, which are heavy n-alkanes, were selected to form binary systems with CO2. The bubble point pressures of each system were obtained through a series of constant component expansion (CCE) experiments. Variation laws and mechanisms of multiphase boundary of heavy n-alkanes-CO2 systems were studied. As CO2 fraction increased, the bubble point pressure of heavy n-alkanes-CO2 systems increased greatly, and the bubble point pressure increased linearly with temperature. When CO2 molar fraction is less than 50%, the bubble point pressure of the heavy n-alkanes-CO2 systems decreased slightly with the increase of carbon number, and the decrease of pressure amplitude decreased with the decrease of CO2 mole fraction. When CO2 molar fraction was 75%, the bubble point pressure of different heavy n-alkane systems increased slightly with the increase of carbon number. When CO2 molar fraction was less than 50%, with the increase of the carbon number, the influence of temperature variation on the bubble point pressure of systems decreased. When CO2 molar fraction was equal to 75%, with the increase of the carbon number, the influence of temperature variation on the bubble point pressure of heavy n-alkanes-CO2 systems did not change. On the analysis of micro scale, the reason for variation laws above is that the long chains and large intermolecular interval of heavy n-alkane has ability to accommodate CO2 molecules and its chain is prone to twist.
[1] 秦积舜, 李爱芬. 油层物理学[M]. 东营: 中国石油大学出版社, 2006.
QIN Jishun, LI Aifen. Fundamentals of petrophysics[M]. Dongying: China University of Petroleum Press, 2006.
[2] 韩海水, 袁士义, 李实, 等. 二氧化碳在链状烷烃中的溶解性能及膨胀效应[J]. 石油勘探与开发, 2015, 42(1): 88-93.
HAN Haishui, YUAN Shiyi, LI Shi, et al. Dissolving capacity and volume expansion of carbon dioxide in chain n-alkanes[J]. Petroleum Exploration and Development, 2015, 42(1): 88-93.
[3] 李实, 张可, 马德胜, 等. 地层油关键组分与CO 2 混相能力的相关性研究[J]. 油气藏评价与开发, 2013, 3(5): 30-33.
LI Shi, ZHANG Ke, MA Desheng, et al. Correlation of miscible ability between key components of formation crude and CO 2 [J]. Reservoir Evaluation and Development, 2013, 3(5): 30-33.
[4] 韩海水, 李实, 陈兴隆, 等. CO 2 对原油烃组分膨胀效应的主控因素[J]. 石油学报, 2016, 37(3): 392-398.
HAN Haishui, LI Shi, CHEN Xinglong, et al. Main control factors of carbon dioxide on swelling effect of crude hydrocarbon components[J]. Acta Petrolei Sinica, 2016, 37(3): 392-398.
[5] 秦积舜, 韩海水, 刘晓蕾. 美国CO 2 驱油技术应用及启示[J]. 石油勘探与开发, 2015, 42(2): 209-216.
QIN Jishun, HAN Haishui, LIU Xiaolei. Application and enlightenment of carbon dioxide flooding in the United States of America[J]. Petroleum Exploration and Development, 2015, 42(2): 209-216.
[6] 沈平平, 廖新维. 二氧化碳地质埋存与提高石油采收率技术[M]. 北京: 石油工业出版社, 2009.
SHEN Pingping, LIAO Xinwei. The technology of carbon dioxide stored in geological media and enhanced oil recovery[M]. Beijing: Petroleum Industry Press, 2009.
[7] LIU Jianguo, QIN Zhangfeng, WANG Guofu, et al. Critical properties of binary and ternary mixtures of hexane + methanol, hexane + carbon dioxide, methanol + carbon dioxide, and hexane + carbon dioxide + methanol[J]. Journal of Chemical & Engineering Data, 2003, 48(6): 1610-1613.
[8] JIMENEZ-GALLEGOS R, GALICIA-LUNA L A, ELIZALDE-SOLIS O. Experimental vapor–liquid equilibria for the carbon dioxide + octane and carbon dioxide + decane systems[J]. Journal of Chemical & Engineering Data, 2006, 51(5): 1624-1628.
[9] CAMPOS C E P S, VILLARDI H G D, PESSOA F L P, et al. Solubility of carbon dioxide in water and hexadecane: Experimental measurement and thermodynamic modeling[J]. Journal of Chemical & Engineering Data, 2009, 54(10): 2881-2886.
[10] SECUIANU C, FEROIU V, DAN G. Phase behavior for the carbon dioxide + n -pentadecane binary system[J]. Journal of Chemical & Engineering Data, 2010, 55(10): 4255-4259.
[11] LAY E N. Measurement and correlation of bubble point pressure in (CO 2 + C 6 H 6 ), (CO 2 + CH 3 C 6 H 5 ), (CO 2 + C 6 H 14 ), and (CO 2 + C 7 H 16 ) at temperature from (293.15 to 313.15) K[J]. Journal of Chemical & Engineering Data, 2010, 55(1): 223-227.
[12] NOUROZIEH H, BAYESTEHPARVIN B, KARIZNOVI M, et al. Equilibrium properties of (carbon dioxide + n -decane + n -octadecane) systems: Experiments and thermodynamic modeling[J]. Journal of Chemical & Engineering Data, 2013, 58(5): 1236-1243.
[13] 韩海水. 原油组分和二氧化碳体系关键状态参数的获取及应用[D]. 北京: 中国石油勘探开发研究院, 2015.
HAN Haishui. Acquisition and application of key state parameters of the crude oil components and CO 2 system[D]. Beijing: Research Institute of Petroleum Exploration & Development, 2015.
[14] LIU Bing, SHI Junqin, SUN Baojiang, et al. Molecular dynamics simulation on volume swelling of CO 2 -alkane system[J]. Fuel, 2015, 143: 194-201.
[15] ZHANG Junfang, PAN Zhejun, LIU Keyu, et al. Molecular simulation of CO 2 solubility and its effect on octane swelling[J]. Energy & Fuels, 2013, 27(5): 2741-2747.
[16] 中华人民共和国国家质量监督检验检疫总局. 油气藏流体物性分析方法: GB/T 26981—2011[S]. 北京: 中国标准出版社, 2012.
General Administration of Quality Supervision, Inspection and Quarantine of the People’s Republic of China. Test method for reservoir fluid physical properties: GB/T 26981—2011[S]. Beijing: China Standards Press, 2012.
