【摘要】 针对G级油井水泥浆体体积收缩问题,对比研究了两种常用外掺料(矿渣和石英粉)对水泥浆体体积稳定性及力学性能的影响,并利用等温量热仪(ICC)、X射线衍射仪(XRD)、压汞仪(MIP)和扫描电镜(SEM)分别测试了两种外掺料对水泥水化放热速率,水泥水化产物、孔结构及水泥石微观形貌的影响。结果表明:80℃下水泥净浆体积收缩主要发生在水化早期,对应水泥石早期抗压强度、抗折强度增长迅速;掺入30%比表面积为340m2/kg的矿渣部分改善浆体体积收缩,150d线收缩率较净浆减小32%,早期抗压强度、抗折强度减小,后期强度增大并超过净浆;掺入30%比表面积为710m2/kg的石英粉加剧了浆体体积收缩,150d线收缩率较净浆增大40%,早期抗压强度、抗折强度远低于净浆及掺30%矿渣水泥。长期水养后部分超细SiO2参与反应,加之细颗粒的填充作用使其150d力学强度超过净浆及掺30%矿渣水泥,即水泥石力学强度不仅与外掺料活性有关,还与其粒径分布和养护龄期密切相关。更多还原

【Abstract】 Based on shrinkage for class G oil well cement slurry in using process, effects of two common admixtures(slag and quartz powder)on volume stability and mechanical properties of class G oil well cement slurry were contrasted, and effects of two common admixtures on early exothermic rate of hydration, hydration products, pore structure and microstructure were characterized by isothermal conduction calorimetery(ICC), X-ray diffraction analyzer(XRD), mercury intrusion porosimetry(MIP)and scanning electron microscope(SEM). The results show that at the temperature of 80℃, the main shrinkage of class G oil well cement slurry occurred during early hydration period, and the early compression strength, flexural strength of cement paste increased rapidly; The volume shrinkage of cement slurry with 30% slag(340 m2/kg)has reduced, the linear shrinkage(150 d)reduced by 32%. the early compression strength,flexural strength of cement paste with 30% slag decreased, but the last strength increased even more than the strength of pure cement paste; The volume shrinkage of cement slurry with 30% quartz powder(710 m2/kg)increased, the linear shrinkage(150 d)increased by 40% and the early compression strength, flexural strength of cement paste with 30% quartz powder lower than that of pure cement paste and cement paste with 30% slag. After long term water-bath curing, part of super fine SiO2 involved in the reaction, and favorable grain composition make the strength(150 d)of cement paste with 30% quartz powder higher than that of pure cement paste and cement paste with 30% slag, so the strength of cement paste was influenced by not only the acticity of admixtures but also the particle size and curing age.更多还原