咸水层压缩空气储能具有规模化与商业化的潜力，是实现“双碳目标”的必然选择。压缩空气注入储层后，使咸水层中水岩作用呈现复杂化演变，是影响储能效率的关键因素，关乎到该储能方式能否保障其长期性和安全性。因此，论文选取砂岩为研究对象，通过室内系列高温高压静态封闭模拟实验，综合运用多种光谱技术表征等测试分析方法，结合地球化学模拟技术，揭示了压缩空气储能作用下水-岩反应过程及影响因素，取得的成果如下：

高温高压条件下，储层中空气溶解度受咸水层温度和压力控制，典型矿物对储层水岩反应过程表现出明显的溶蚀特征。50℃、12 Mpa（相当于储层埋深1200 m的压力）条件下，压缩空气在微咸水溶液中的溶解度为0.11 mol/kg，其溶解引起CO₃^2-等离子浓度变化，使pH降低了0.62，组分气体溶解度随压力升高、一定条件下随温度降低而增大。压缩空气作用下，高岭石、绿泥石等发生了明显溶蚀，但溶蚀特征各异。黏土矿物因呈现较高溶解度，是关键反应性矿物。

针对50℃、12 Mpa反应条件下，水-岩-气反应呈现出阶段性溶解、沉淀与转化特征，砂岩矿物成分和孔渗特性显著改变。第一阶段以矿物溶蚀、次生沉淀为主，pH随气体快速溶解大幅下降。钠长石溶解，绿泥石向孔隙填充式溶蚀，出现文石型碳酸盐沉淀，使孔隙度增加，渗透率减小。第二阶段为次生沉淀为主、矿物继续溶蚀，pH回升至弱碱性。原生绿泥石溶解使水中SiO₂增长变缓，体系孔隙度升高。次生沉淀大量填充溶蚀孔洞，最终使原有的渗透率降低13.26 mD。第三阶段为次生石英碱性溶蚀，碳酸钙沉淀使CO₃^2-离子浓度进一步降低，长石与绿泥石继续溶解，孔隙度增大至21.8%。

受关键因素影响，矿物成分发生较大改变，其中延长储能周期对反应的影响显著。在16天封闭条件下，矿物溶蚀程度远大于日循环和周循环尺度，出现大尺寸溶蚀裂隙，大量六方多锥型簇状碳酸钙和绿泥石沉淀增加，使孔隙通道结构被显著改造，其渗透率较实验前降低15.53 mD。随着温度与压力升高，溶蚀与碳酸盐沉淀增强，体系中的孔隙度增高至22.31%，渗透率减少量达14.63 mD。石英砂岩孔隙中充填了绿泥石和高岭石，其渗透率降低最多，灰岩因缺少黏土矿物组分，其孔渗特性变化较小。

地球化学模拟技术再现了矿物反应情景，高岭石和白云石作为次生沉淀参与反应，石英先溶解后析出。PHREEQC模拟压缩空气条件下的水-岩相互作用过程的结果，与实验分析过程较一致，且模型提供矿物组分的定量转化。结果显示溶液为弱碱性，钠长石、绿泥石在前期溶解较快，石英在少量溶解后析出，形成次生沉淀，验证了高岭石和白云石的沉淀，分别增加约6×10^-6，其后向绿泥石沉淀转化。

咸水层压缩空气储能实验研究表明，高温高压下的不同岩性，孔隙度和渗透率由于黏土矿物的含量不同，会发生较大的变化，因此，不同沉积层岩可以作为压缩空气储能系统的封闭边界，在选择储层时，需要考虑不同岩性的黏土矿物含量。

Compressed air energy storage in aquifer has the potential of scale up and commercialization, and is an inevitable choice to achieve the "double carbon goal". After compressed air is injected into the reservoir, the evolution of water-rock interaction in the brackish water layer is complicated, which is the key factor affecting the energy storage efficiency and whether the storage method can guarantee its long-term and safety. Therefore, the thesis selected sandstone as the research object, through a series of indoor high-temperature and high-pressure static confinement simulation experiments, comprehensive use of a variety of spectroscopic technology characterization and other testing and analysis methods, combined with geochemical simulation technology, to reveal the process of water-rock reaction under the action of compressed air energy storage and the influencing factors, the results achieved are as follows:

Under high temperature and pressure conditions, the solubility of air in the reservoir is controlled by the temperature and pressure of the brackish water layer, and typical minerals show obvious dissolution characteristics to the water-rock reaction process of the reservoir. 50℃, 12 Mpa (equivalent to the pressure of the reservoir burial depth of 1200 m) conditions, the solubility of compressed air in the brackish water solution is 0.11 mol/kg, and its dissolution causes a change in the concentration of CO₃^2- plasma The pH was reduced by 0.62, and the solubility of component gases increased with the increase of pressure and with the decrease of temperature under certain conditions. Under the action of compressed air, kaolinite and chlorite underwent significant dissolution, but the dissolution characteristics were different. Clay minerals are key reactive minerals because they present higher solubility.

For 50℃ and 12 Mpa compressed air-water-rock reaction conditions, the water-rock-air reaction shows the characteristics of stage dissolution, precipitation and transformation, and the sandstone mineral composition and pore permeability characteristics change significantly. The first stage is dominated by mineral dissolution and secondary precipitation, and the pH decreases significantly with rapid gas dissolution. Sodium feldspar dissolves, chlorite dissolves to pore-filling, and aragonite-type carbonate precipitation appears, which increases porosity and decreases permeability. In the second stage, secondary precipitation dominates, minerals continue to dissolve, and pH rises back to weak alkalinity. The dissolution of primary chlorite slows down the growth of SiO₂ in water and increases the porosity of the system. The secondary precipitation fills a large number of dissolved pores and eventually reduces the original permeability by 13.26 mD. The third stage is alkaline dissolution of secondary quartz, where calcium carbonate precipitation further reduces the concentration of CO₃^2- ions, feldspar and chlorite continue to dissolve, and the porosity increases to 21.8%.

The mineral composition was greatly altered by key factors, among which the extended storage period had a significant effect on the reaction. Under the 16-day closed conditions, the degree of mineral dissolution was much larger than the daily and weekly cycle scales, large size dissolution fractures appeared, and a large amount of hexagonal multi-cone cluster calcium carbonate and chlorite precipitation increased, so that the pore channel structure was significantly modified, and its permeability decreased by 15.53 mD compared with that before the experiment. with the increase of temperature and pressure, the dissolution and carbonate precipitation enhanced, and the porosity in the system increased to 22.31%, and The permeability of quartz sandstone pores filled with chlorite and kaolinite decreased the most, and the pore permeability of chert changed less due to the lack of clay mineral components.

(4)  Geochemical simulation technique reproduces the mineral reaction scenario, where kaolinite and dolomite participate in the reaction as secondary precipitation and quartz dissolves first and then precipitates. the results of PHREEQC simulating the water-rock interaction process under compressed air conditions are more consistent with the experimental analysis process, and the model provides quantitative transformation of mineral components. The results show that the solution is weakly alkaline, sodium feldspar and chlorite dissolve faster in the early stage, quartz precipitates after a small amount of dissolution and forms secondary precipitation, which verifies the precipitation of kaolinite and dolomite, increasing about 6×10^-6 respectively, and then converts to chlorite precipitation.

The experimental study of compressed air energy storage in brackish water layer shows that the porosity and permeability of different lithologies under high temperature and pressure will change greatly due to the different content of clay minerals, therefore, different sedimentary layer rocks can be used as the closed boundary of compressed air energy storage system, and the content of clay minerals of different lithologies needs to be considered when selecting the reservoir.