Application of a Digital Oil Model to Solvent-Based Enhanced Oil Recovery of Heavy Crude Oil
Application of a Digital Oil Model to Solvent-Based Enhanced Oil Recovery of Heavy Crude Oil
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DOI：
10.1021/acs.energyfuels.9b02801
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发表时间：
2019-10
期刊：
影响因子：
5.3
通讯作者：
M. Iwase;Yunfeng Liang;Y. Masuda;Masato Morimoto;T. Matsuoka;E. Boek;Y. Kaito;K. Nakagawa
中科院分区：
文献类型：
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作者：
M. Iwase;Yunfeng Liang;Y. Masuda;Masato Morimoto;T. Matsuoka;E. Boek;Y. Kaito;K. Nakagawa
为了研究三次采油过程，我们构建了一种活重质原油(数字油)的分子模型，并研究了原油在储集层温度和宽压力范围内的性质。通过闪光计算确定了数字油液相组成，并通过分子动力学模拟计算了数字油的密度和粘度。计算的密度和粘度与实验数据吻合较好。为了评价不同溶剂对提高原油采收率的效果，我们计算了不同溶剂添加到数字油中时油品性质的变化。首先，我们比较了甲烷和二氧化碳(CO₂)。结果表明，CO-₂具有较好的降油降粘、溶胀和油内扩散作用。其次，我们评估了11种不同的溶剂：氮气、CO₂、甲烷、乙烷、丙烷、正庚烷、正辛烷、甲苯和三种二甲苯异构体(邻二甲苯、间二甲苯和对二甲苯)的有效性。乙烷对原油降粘和溶胀的影响最大，CO₂的扩散系数最大。结果表明，乙烷和CO-₂是该原油的适宜溶剂。此外，值得注意的是，三种二甲苯异构体的粘度降幅不同，但溶胀系数和扩散系数没有差异。二甲苯异构体不同的旋转运动特性可以解释粘度差异的原因。这些信息将有助于数字石油模型的进一步发展。
To investigate enhanced oil recovery processes, we constructed a molecular model of a live heavy crude oil (digital oil) and studied the crude oil properties at the reservoir temperature and a wide range of pressures. We identified the liquid phase components of the digital oil by flash calculation and calculated the density and viscosity by molecular dynamics simulations. The calculated density and viscosity were in good agreement with experimental data. To evaluate the effectiveness of various solvents to enhance oil recovery, we calculated the oil property changes when different solvents were added to the digital oil. First, we compared methane and carbon dioxide (CO₂). The results indicated that CO₂ was more effective in terms of oil-viscosity reduction, oil swelling, and diffusion in the oil. Second, we evaluated the effectiveness of 11 different solvents: nitrogen, CO₂, methane, ethane, propane, n-heptane, n-octane, toluene, and three xylene isomers (o-xylene, m-xylene, and p-xylene). Ethane had the greatest effect on oil-viscosity reduction and oil swelling, and CO₂ had the highest diffusion coefficient. From these results, ethane and CO₂ are appropriate solvents for this crude oil. In addition, it is interesting to note that the decreases of the viscosity among the three xylene isomers were different, but there were no differences in the swelling factors and diffusion coefficients. The different rotation motion characteristics of the xylene isomers can account for the viscosity differences. Such information will be helpful for further development of digital oil models.