论文标题
反应性传输的基本研究：对长期二氧化碳（CO2）隔离的影响
Fundamental Investigation of Reactive-Convective Transport: Implications for Long-Term Carbon dioxide (CO2) Sequestration
论文作者
论文摘要
密度驱动的对流和化学反应是永久存储二氧化碳含有盐水含水层的首选机制。这项研究使用2D Visual Hele-Shaw细胞来评估和可视化由于重力不稳定性而形成的密度驱动对流，也称为Rayleigh-Taylor不稳定性。实验的主要目标是了解气态二氧化碳大传递到具有不同初始离子浓度和流动渗透性的盐水的各种机制。此外，还研究了二氧化碳流速，注入位置，储层浸入角度和渗透率异质性的影响。我们观察到，与没有溶解盐的情况相比，盐的存在导致对流发作和对流手指波长更大。此外，实验数据显示涉及浸入时二氧化碳手指之间的横向混合较高。视觉研究还表明，通过对流手指的前进速率测量的二氧化碳溶解速率取决于盐水中存在的离子的类型和浓度。与不存在盐相比，观察到溶解盐的溶液的二氧化碳溶解度为0.38-0.77倍。尽管在存在盐的情况下会减慢对流流量，但从定性和定量结果观察到，扩散通量得到了增强。此外，通过使用流屏屏障引入的降低的渗透性降低，导致许多区域没有被溶解的CO2扫除，表明效率低下。我们还研究了流动屏障内离散高电导率骨折的影响，该作用显示出不平坦的垂直扫描和增强的流动通道。最后，确定并讨论了有关库2泄漏风险的参数。
The density-driven convection coupled with chemical reaction is the preferred mechanism for permanently storing CO2 in saline aquifers. This study uses a 2D visual Hele-Shaw cell to evaluate and visualize the density-driven convection formed due to gravitational instabilities, also known as Rayleigh-Taylor instability. The primary goal of the experiments is to understand the various mechanisms for the mass transfer of gaseous CO2 into brine with different initial ionic concentrations and flow permeability. Moreover, the impact of CO2 flow rates, injection locations, reservoir dipping angle, and permeability heterogeneity is also investigated. We observed that the presence of salts resulted in earlier onset of convection and a larger convective finger wavelength than the case with no dissolved salts. In addition, experimental data showed a higher lateral mixing between CO2 fingers when dipping is involved. The visual investigation also revealed that the CO2 dissolution rate, measured by the rate of the convective fingers advance, depends on the type and concentration of the ions present in the brine. The CO2 dissolution for solutions with varying salt dissolved, indicated by the area of the pH-depressed region, is observed to be 0.38-0.77 times compared to when no salt is present. Although convective flow is slowed down in the presence of salts, the diffusive flux is enhanced, as observed from both qualitative and quantitative results. Moreover, the reduced formation permeability, introduced by using a flow barrier, resulted in numerous regions not being swept by the dissolved CO2, indicating an inefficient dissolution. We also investigated the effect of discrete high conductivity fractures within the flow barriers, which showed an uneven vertical sweep and enhanced flow channeling. Lastly, the parameters regarding CO2 leakage risk during storage are identified and discussed.
