固井水泥浆的水化规律

Hydration law of cementing slurry

油气井固井过程就是水泥浆不断水化的过程,采用直接测试的方法考察固井水泥浆在不同温度、水灰比、掺料和外加剂条件下的水化规律。结果表明：随着温度升高,水化进程加快,水化温升峰值增大;水灰比的增大使温升峰值降低,水灰比为0.4-0.55时影响较大;粉煤灰和矿渣能推迟峰值出现时间,降低水化温升,但矿渣降低程度不如粉煤灰明显,掺量增加,水化后期温升较大;氯化钙对水化温升的影响随掺量的增加而变大,增大水化温升,加快峰值出现,但掺量较大会引起水化温升过高。

Well cementation is the process of cementing slurry hydration.Hydration law of cementing slurry was studied under different temperatures,water to cement ratios and admixtures through direct measurement.The results show that high temperature can obviously increase the temperature-rise of the cement and accelerate the hydration process.Increasing water to cement ratio can reduce the temperature-rise,and it has a greater affection when the range of water to cement ratio is 0.4-0.55.Both slag and fly ash can reduce the temperature-rise and retard the time to peak.In the extent of reducing temperature-rise,slag is not obviously as good as fly ash.And more slag can increase the later temperature-rise.CaCl2 can increase temperature-rise.The impact on temperature-rise is becoming larger with the increase of CaCl2.But more CaCl2 will cause excessive temperature-rise.