【摘要】 为了解决目前油井水泥拌合料配比设计困难的难题,进一步拓展漂珠微硅类低密度水泥体系的应用范围,基于颗粒级配增强、纤维增韧的技术思路,研制了颗粒级配增强材料KZ和早强剂ZR,并优选了长度为600μm和1050μm的化学改性纤维作为增韧材料,最终在1.15～1.45g/cm3范围内优化设计出4种不同密度的新型四元体低密度水泥体系,并对该体系的水泥石力学性能和浆体性能进行了系统评价.实验结果表明:四元体系强度明显高于目前现场使用的同一级别的低密度水泥,改性纤维的架桥阻裂作用可显著提高水泥石韧性,水泥浆失水量和游离液含量较低,防窜能力强,稠化和流变性能满足要求,体系稳定性好,验证了四元体系粒径分布的合理性.研究结果为多元体油井水泥体系设计提供了一条新途径.更多还原

【Abstract】 To tackle with the difficulty in current solid mixture proportion design for oil well cement,and broaden the application range of low density cement system using floating potential and microsilica,the technical conception with particle size distribution for strength improvement and fiber for toughness enhancement was adopted. With the introduction of self-made reinforcing material KZ and early-strength toughening agent ZR,combining with the optimization of chemically modified fiber at the lengths of 600 μm and 1 050 μm as the toughness reinforcing material,four kinds of different new quaternary lightweight cement system were finally developed with the density ranging from 1.15 g/cm3 to 1.45 g/cm3. Meanwhile,systematic evaluation was conducted on the mechanical properties of set cement and the performance of cement slurry. Experimental results show that the quaternary systems have better strength than the currently employed lightweight cement systems of the same density in field, and the bridging and anti-fracturing function of imbedded fiber can significantly improve the toughness of set cement. The cement slurry shows lower fluid loss and free water content,favorable consistence development,strong anti-channeling ability,and good rheological property and stability. Hence,the rationality of particle size distribution for the developed quaternary system is validated. Research results offer a new approach for the formulation design of multivariate oil well cement system.更多还原