超高密度水泥浆加重剂粒径和加量优化模型

针对超高密度水泥浆由于体系中惰性颗粒较多，水泥浆流变性能与水泥石力学特性之间存在矛盾的问题，以颗粒级配和紧密堆积原理为理论依据，通过计算水泥石单位面积上加重剂所占面积比，建立了加重剂不同粒径匹配模型和不同粒径加重剂加量的数学模型。调整体系加重剂的颗粒粒径匹配，并对加量进行优化计算，使抗压强度满足设计要求。模型计算出添加三级颗粒时，粒径的最佳匹配关系为r₁∶r₂∶r₃=1.00∶0.40∶0.07，三级颗粒的体积加量为V₁∶V₂∶V₃≈354∶45∶1。大量实验表明，密度为2.6g/cm3的超高密度水泥浆经过合理粒度级配、加量控制的水泥石抗压强度可达到12MPa（24h，50℃常压养护）以上，且流动性能良好，在现场能够一次完成配浆。

THE OPTIMAL METHOD AND WEIGHT AGENT GRANULAR SIZE OF SUPER HIGH DENSITY CEMENT SLURRY

Because in the super high density cement slurry there are a lot of inert particles and the contradiction between cement slurry rheological property and cement set mechanical behavior，based on these conditions，the weight agent granular size model and the weight agent model are established by using the particlesize distribution and the theory of close packing and calculating the area percent in the cement set uint area.The match of weight agent granular size in the system is adjusted and its quantity optimized，cement set anticompression strength design meets requiremet while calculating the 3rated grains with the model，the best match relation of weight agent granular size is r₁∶r₂∶r₃=1.00∶0.40∶0.07，and the quantity ratio of weight agent is V₁∶V₂∶V₃=354∶45∶1.A lot of experiment demonstrate the cement set anticompression strength of 2.6g/cm3 can reach 12MPa （50℃，24h）by reasonable match of weight agent granular size and controlling its quantity，and the rheological property of super high density cement slurry is very good，so it is very easy to produce in the different oilfield.