Pore-scale simulation of miscible viscous fingering with dissolution reaction in porous media
Pore-scale simulation of miscible viscous fingering with dissolution reaction in porous media
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DOI：
10.1063/5.0045051
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发表时间：
2021-03-01
影响因子：
4.6
通讯作者：
Luo, Kai H.
中科院分区：
文献类型：
--
作者：
Lei, Timan;Luo, Kai H.
全球气候变化正在发生，但可能通过地质二氧化碳（CO 2）封存技术来缓解。为了全面了解这种方法，我们使用一个新的多弛豫时间格子玻尔兹曼模型在多孔介质中的两种可混溶流体之间的位移进行孔隙尺度模拟。该研究首次尝试研究混相驱中粘性指进动力学，考虑了粘度差和溶解反应的共存。模拟结果捕获不同的指进模式，取决于溶解（达姆科勒数Da），扩散（Peclet数Pe），和粘度对比度（粘度比R）。从不稳定粘性流的模拟中发现，溶解延迟指进的开始，减缓指进的传播，抑制或加强后期指进强度。在稳定粘度对比的模拟中，当溶解足够快时，驱替具有指进现象。此外，我们进行了参数研究，以评估Pe，R和DA的影响。结果表明，增加Pe或R不稳定的指法，但增加DA首先抑制，并逐渐加剧指法。最后，对于每个固定的Da，我们确定在Pe-R相平面中稳定和不稳定制度之间的相边界。提出了一个统一的标度律来近似不同Da值下的边界线。通过比较反应和非反应的情况下，我们分为四个不同的制度：稳定，不稳定，反应稳定，反应不稳定。这些孔隙尺度的认识有助于理解和预测CO2地质封存过程中的驱替稳定性，对封存效率和安全性的预评价具有重要意义。
Global climate change is happening but may be mitigated by the technology of geological carbon dioxide (CO 2) sequestration. To gain comprehensive insights into this approach, we perform pore-scale simulations of displacement between two miscible fluids in porous media using a new multiple-relaxation-time lattice Boltzmann model. This study marks the first attempt to investigate viscous fingering dynamics in miscible displacement, considering the coexistence of viscosity contrast and dissolution reaction. Simulation results capture different fingering patterns that depend on dissolution (Damkohler number Da), diffusion (Peclet number Pe), and viscosity contrast (viscosity ratio R). From simulations of unstable viscous flows, dissolution is found to delay fingering onset, slow down fingering propagation, and inhibit or reinforce the late-stage fingering intensity. In simulations with stable viscosity contrasts, the displacement features fingering phenomena when dissolution is fast enough. In addition, we conduct a parametric study to assess the impact of Pe, R, and Da. The results suggest that increasing Pe or R destabilizes fingering, but increasing Da first suppresses and gradually intensifies fingering. Finally, for every fixed Da, we determine the phase boundary between stable and unstable regimes in a Pe-R phase plane. A unified scaling law is developed to approximate boundary lines obtained under different Da values. By comparing reactive and nonreactive cases, we classify four distinct regimes: stable, unstable, reactive stable, and reactive unstable. These pore-scale insights are helpful in understanding and predicting the displacement stability during the geologicalCO 2 sequestration, which is of importance to the pre-evaluation of the storage efficiency and safety.