高温合成水化硅酸钙对油井水泥水化进程的影响

Effects of High Temperature Synthesized Calcium Silicate Hydrate on Hydration Process of Oil Well Cement

以氧化钙、氢氧化钙、白炭黑等为主要原料,在160℃、80 MPa下,通过高温水热合成法合成了颗粒状水化硅酸钙晶体,并研究了其对油井水泥水化的影响。结果表明,合成的颗粒状水化硅酸钙晶体能使水泥水化放热量增加超过1倍,且能够显著加快水泥浆的放热速率;合成材料的粒径大小对水泥浆水化过程有一定影响,粒径为纳米级时水泥浆放热速率和总放热提高更为明显,一定加量下具有早强、增强水泥石强度的作用。研究表明水泥的钙硅比会影响水泥水化规律,相关机理需要进一步深入研究。

A granular crystalline calcium silicate hydrate has been synthesized through high temperature hydrothermal reaction at 160℃and 80 MPa with CaO,Ca(OH)_(2) and white carbon black(a silica)as the major raw materials.Study on the effects of the synthesis product on the hydration process of oil well cement showed that the use of the synthesized calcium silicate hydrate caused the released heat of hydration of the cement to double,and was able to significantly accelerate the heat release process of the cement slurry.The particle sizes of the calcium silicate hydrate have some effects on the hydration process of the cement.When the particle size is in nano-scale,the rate of heat release and the total heat released of the cement slurry increase more obviously.By adding a specific amount of the calcium silicate hydrate into a cement slurry,the compressive strength of the set cement,the overall properties of the cement slurry and the set cement can all be improved.The study has shown that the ratio of SiO_(2)/CaO of the cement affects its hydration process.