Effect of capillary pressure and salinity on CO2 solubility in brine aquifers
Effect of capillary pressure and salinity on CO2 solubility in brine aquifers
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毛细管压力和盐度对盐水含水层中 CO2 溶解度的影响
DOI：
10.1016/j.ijggc.2016.12.012
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发表时间：
2017-02
影响因子：
3.9
通讯作者：
Di Yuan
中科院分区：
文献类型：
--
作者：
Zhang Yuan;Lashgari Hamid R;Sepehrnoori Kamy;Di Yuan
CO2封存是将CO2注入枯竭油气藏或深层含水层，通过多种机制封存CO2的过程。由于超临界CO2相和盐水在可渗透介质中在很宽的压力和温度范围内是不混溶的，因此CO2和盐水之间存在毛细管压力。虽然已经有许多努力来研究CO2在盐水含水层中的溶解度，但大多数已发表的模型在相行为计算中忽略了毛细管压力的影响，以调查溶解捕获量。这项工作的重点是毛细管压力和盐度对溶解度的CO2在该地区，盐水饱和度增加，从干燥区和/或以下的残余饱和度向100%的水饱和区在过渡区的CO2饱和度的影响。为此，我们开发了一个新的模型占水和气相压力的不平等计算的溶解度CO2在盐水相。应用Peng-Robinson状态方程和局部平衡判据。毛细管压力是相饱和度的函数。我们验证了所提出的方法对实验测量。随后，我们进行了案例研究，包括毛细管压力对CO2的溶解度，水的蒸发和K值的影响。结果表明，增加毛细管压力导致CO2溶解度的降低。这种影响对CO2溶解度的重要性取决于代表岩石物理性质的毛细管压力曲线。当毛细管压力从0.48 MPa增加到9.45 MPa时，CO2溶解度下降了23%。此外，还研究了毛细管压力对平衡常数（K值）和水蒸发的影响，这可用于在商业油藏模拟器中获得准确的模拟结果。此外，我们分析了盐度对CO2溶解度的影响，并比较了有无毛细平衡的结果。不同盐度之间的比较表明，CO2的溶解度下降近49%，当盐度从0到4摩尔的NaCl水溶液中增加。这是首次从理论上探讨毛管压力效应对CO2地质封存的影响。
CO2storage is a process in which CO2is injected into depleted oil and gas reservoirs or deep aquifers to store CO2through several mechanisms. Since supercritical CO2phase and saline brine are immiscible at a wide range of pressure and temperature in a permeable medium, capillary pressure exists between the CO2and saline brine. Although there have been many efforts to study solubility of CO2in brine aquifers, the most published models neglect the capillary pressure effect during phase behavior calculations to investigate the amount of dissolution trapping. This work focuses on effects of capillary pressure and salinity on solubility of CO2in the region, where brine saturation increases from a dried zone and/or below residual saturation toward a 100% water saturated zone at the transition zones of CO2saturations. For this purpose, we developed a new model accounting for inequalities of aqueous and gas phase pressures to calculate the solubility of CO2in the brine phase. Peng-Robinson equation of state and criterion for local equilibrium are applied. The capillary pressure is a function of phase saturation. We verified the proposed method against the experimental measurement. Subsequently, we performed the case studies including the capillary pressure effect on the solubility of CO2, water vaporization andK-values. The results indicate that increasing capillary pressure leads to a reduction in CO2solubility. The importance of this effect on CO2solubility depends on the capillary pressure curve which represents petrophysical properties. In a case considered in this paper, the decrease of CO2solubility is 23% when the capillary pressure increases from 0.48 to 9.45 MPa. Additionally, effects on equilibrium constant (K-values) and water vaporization were also investigated in the presence of capillary pressure, which can be used to obtain accurate simulation results in commercial reservoir simulators. Furthermore, we analyzed the influence of salinity on CO2solubility and compared the results with and without the capillary equilibrium. Comparisons between different salinities reveal that CO2solubility decreases nearly 49% when the salinity increases from 0 to 4 mol aqueous NaCl solutions. It is the first attempt to theoretically investigate the capillary pressure effect on the subject of CO2geological storage.
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影响因子：
5.6
作者：
Hongjun Zhao;X. Liao;Yanfang Chen;Xiaoliang Zhao
通讯作者：
Hongjun Zhao;X. Liao;Yanfang Chen;Xiaoliang Zhao
DOI：
10.2118/173221-ms
发表时间：
2015-02
期刊：
--
影响因子：
--
作者：
B. Nojabaei;R. Johns
通讯作者：
B. Nojabaei;R. Johns
DOI：
10.2118/171028-ms
发表时间：
2014-10
期刊：
--
影响因子：
--
作者：
B. Nojabaei;Nithiwat Siripatrachai;R. Johns;T. Ertekin
通讯作者：
B. Nojabaei;Nithiwat Siripatrachai;R. Johns;T. Ertekin
DOI：
10.1080/10473289.2003.10466206
发表时间：
2003-06
影响因子：
2.7
作者：
C. M. White;B. Strazisar;E. Granite;J. S. Hoffman;H. Pennline
通讯作者：
C. M. White;B. Strazisar;E. Granite;J. S. Hoffman;H. Pennline
影响因子：
5.3
作者：
L. Nghiem;P. Sammon;J. Grabenstetter;H. Ohkuma
通讯作者：
L. Nghiem;P. Sammon;J. Grabenstetter;H. Ohkuma