Abstract: With the oil exploration tending to approach hydrocarbon reservoir, both the length of cementing and the bottom temperature increase accordingly. The temperature resistance of a high temperature retarder needs to be improved. This research synthesized a polymer from AMPS and IA(Itaconate). The synthesis process was optimized by single factor method. With 1% initiator at mixing 6h under 60℃, when the monomer ratio of n(AMPS):n(IA) was 50:20, the conversion rate and initial setting time was the highest. High temperature retarder LY was made by mixing with the polymer and hydroxy carboxylate. The application of this temperature retarder LY in low-density cement showed that this LY retarder had a low temperature sensitivity, confirmed by initial setting time. The dispersion and stability of LY was confirmed by LY's improvement on the rheology of cement slurry. The thickening curve at high temperatures demonstrated that LY can be temperature resistant at as high as at 125℃, satisfying the cementing requirements. The effects of the retarder on cement were analyzed by XRD, providing more data in the investigation of retarding mechanism.

Key words: retarder, high temperature resistance, complex, low-density cement, temperature sensitivity

摘要： 随着石油勘探开发向深部油气层发展,固井长度增加,井底温度升高,需要提高缓凝剂的抗温能力并降低其温敏性。本文首先以AMPS和IA(衣康酸)这两种单体为原料合成共聚物,通过单因素实验法优化合成条件,得出最优合成条件为n(AMPS):n(IA)=50:20,反应温度60℃,引发剂加量1%。再将AMPS/IA共聚物与一种多羟基羧酸盐复配得到新型高温缓凝剂LY,并将该缓凝剂LY应用于低密度水泥浆体系中,通过中、高温条件下的稠化时间对比说明缓凝剂LY对温度的敏感性,实验证实LY的温敏性较小;并通过缓凝剂LY对水泥浆流变性的影响说明缓凝剂的分散性及稳定性,结果证明缓凝剂LY的稳定性较好,并可改善水泥浆的流变性;通过125℃下的高温稠化曲线可知该缓凝剂可抗温度达到125℃,具备高温缓凝剂特性,能够满足固井的要求。再通过XRD谱图分析缓凝剂对低密度水泥石的影响,并最终探讨缓凝机理。

关键词: 缓凝剂, 抗高温, 复配, 低密度水泥体系, 温敏性