Acid-resistant cements for geothermal wells: sodium silicate activated slag/fly ash blends
Acid-resistant cements for geothermal wells: sodium silicate activated slag/fly ash blends
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DOI：
10.1680/adcr.2005.17.2.65
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发表时间：
2005-04
影响因子：
2
通讯作者：
T. Sugama;T. Putte
中科院分区：
文献类型：
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作者：
T. Sugama;T. Putte
通过改变SiO2/Na 2 O摩尔比和水玻璃活化矿渣/F级粉煤灰（SSASF）掺量两个参数，制备了水玻璃活化矿渣/F级粉煤灰（SSASF）混合水泥。根据硅酸钠活化剂中的比例和矿渣/粉煤灰重量比，然后在100、200和300°C下对它们进行高压灭菌。通过将高压灭菌的SSASF水泥暴露于90°C含CO2的H2SO 4（pH 1.1）中15天，评估其作为耐酸地热井水泥的有用性。在这两个参数的组合中，矿渣/粉煤灰比为50/50的水泥和SiO2/Na 2 O比为2·50的激发剂组合对抑制酸蚀效果最好。该水泥酸蚀失重小于7%。这种最小的酸侵蚀的主要贡献者是由粉煤灰中的莫来石和从活化剂释放的Na离子之间的相互作用形成的沸石相。这种水泥的其他特性包括其水泥浆在室温下约1770分钟的长凝结时间，以及2.4 × 10−4至1.9 × 10−4的水渗透率。
Sodium silicate activated slag/class F fly ash (SSASF) blend cements were prepared by varying two parameters, the SiO2/Na2O mol. ratio in the sodium silicate activator, and the slag/fly ash weight ratio, and then autoclaving them at 100, 200 and 300°C. The usefulness of the autoclaved SSASF cements as acid-resistant geothermal well cements was evaluated by exposing them for 15 days to 90°C CO2-laden H2SO4 (pH 1·1). Among the combination of these two parameters, the most effective one in inhibiting acid erosion consisted of 50/50 slag/fly ash ratio cement and 2·50 SiO2/Na2O ratio activator. The weight loss by acid erosion of this cement was less than 7%. The major contributor to such minimum acid erosion was the zeolite phase formed by interactions between the mullite in fly ash and the Na ion liberated from the activator. Further characteristics of this cement included a long setting time for its slurry of approximately 1770 min at room temperature, and a water permeability ranging from 2·4 × 10−4 to 1·9 ...