Abstract Decalcification of cement in solutions of carbonated brine is important to a host of engineering applications, especially in subsurface service environments where cementitious materials are frequently utilized as engineered barriers for wellbore seals, as well as shaft and drift seals and waste forms for nuclear waste disposal. Analysis of leaching simulations and experiments shows that, depending on solution compositions (dissolved CO2 concentration, pH, Ca ion concentration), calcite precipitation occurring during leaching of cement in contact with carbonated brine can have a significant impact on cement reactivity, in some instances leading to complete arrest of reactivity via calcium carbonate “pore-clogging”. We present modeling and experimental results that examine the range of solution conditions that can lead to pore-clogging. Analysis of the results shows that distinct regimes of leaching behavior, based on pH and pCO2, can be used to form a framework to better understand the occurrence of pore-clogging.

中文翻译：

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碳酸盐化盐水暴露过程中碳酸钙沉淀及其对油井水泥降解影响的实验与模拟研究

摘要 碳酸盐水溶液中水泥的脱钙对许多工程应用很重要，特别是在地下服务环境中，胶结材料经常被用作井眼密封的工程屏障，以及用于核废料处理的轴和漂移密封件和废物形式。 . 对浸出模拟和实验的分析表明，根据溶液组成（溶解的 CO2 浓度、pH、Ca 离子浓度），在与碳酸盐水接触的水泥浸出过程中发生的方解石沉淀会对水泥反应性产生重大影响，在某些情况下会导致通过碳酸钙“孔堵塞”完全阻止反应性。我们提供了建模和实验结果，以检查可能导致孔隙堵塞的溶液条件范围。