超高温超高密度防气窜水泥浆

针对超高温超高密度水泥浆设计中难于协调的超高密度与高强度、良好流动性与浆体稳定性的矛盾问题,利用粒度级配原理建立了以水泥为水化胶凝材料和颗粒表面存在吸附水化膜的三级颗粒紧密堆积粒度级配新模型,并应用该模型通过室内优化和添加剂优选实验,实现了以还原铁粉和铁矿粉加重、硅粉热稳定和微硅充填的双三级颗粒级配的组配加重,进行超高密度水泥浆的实验优化。开发出了抗温达200℃,密度达2.82 g/cm3的超高密度防气窜水泥浆体系。室内评价结果表明,该体系综合性能协调良好,防气窜能力强,说明所建立的三级颗粒级配新模型和应用该模型采用双三级颗粒级配进行超过密度水泥浆实验设计的可靠性和实用性。

Ultra High Temperature and Ultra High Density Cement Slurry withGas-channeling Inhibition

Ultra high density cement slurries always have rheology and stability that do not satisfy the needs for field operation. In laboratory studies, reduced iron powders and ground hematite was used in an effort to obtain a cement slurry with ultra-high density. This cement slurry was further treated with silica fume and micro silica to improve its high temperature stability. The principles behind these experiments are the so-called “close-packing of three different particle sizes” model. The prepared cement slurry has temperature stability of 200 ℃ and density of 2.82 g/cm3. In laboratory evaluation, it shows satisfactory anti-channeling capacity and good rheology, showing that the model is reliable and feasible in designing ultra-high cement slurries.