Mechanical Properties and Microstructure of Self-healing Oil Well Cement
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摘要: 关于自修复剂掺入水泥浆后对水泥石力学性能及微观结构的影响研究较少。自修复乳液掺量分别为0%、5%、10%、15%和20%,液固比均为0.44,各水泥浆试样在90 ℃水浴中养护3 d。结果表明,自修复乳液的掺入,降低了水泥石的弹性模量,随掺量的增加,水泥石的弹性模量降低较显著;自修复水泥石的强度高于普通水泥石,掺量较小时抗压强度更高,掺量较大时,抗折强度增幅更大。自修复乳液改变了水泥水化产物Ca(OH)2晶体的微观形貌,使其不再呈叠片状堆积,而是乱向、松散分布且晶体形貌不规则,自修复胶粒沉淀分布于水化产物凝胶网络结构之间。自修复乳液降低了水泥石的孔隙率,增加了水泥石的平均孔径和最可几孔径。Abstract: The mechanical properties and microstructure of self-healing cement were studied. The adding amount of self -healing emulsion was 0, 5%, 10%, 15% and 20% respectively. The samples were cured under the condition of 90 degrees in the water for 3 days. The results showed that the elastic modulus of cement decreased with the incorporation of self-healing emulsion. With the increase of the dosage, the elastic modulus of cement decreased significantly. The strength of self-healing cement paste was higher than that of normal oil well cement. The compressive strength was higher with small amount addition, and the increase of flexural strength was greater with increase of addition. The microstructure of hydroxide crystal appeared scattered and loose instead of regular hexagonal. Self-healing colloidal particles were distributed between the network structures of hydration product gel. The porosity was reduced and the average and most probable pore size increased of self-healing cement.
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Key words:
- Oil well cement /
- Self-healing latex /
- Elastic modulus /
- Micro morphology /
- Pore structure
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表 1 自修复乳液水泥浆配方的配比
编号 油井水泥/% 水/% 自修复乳液/% 消泡剂/% 液固比/% C0 100 44 0 0.1 44 C5 100 39 5 0.2 44 C10 100 34 10 0.3 44 C15 100 29 15 0.4 44 C20 100 24 20 0.5 44 -
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