改性乙烯醋酸乙烯酯共聚物对水泥浆性能的影响

发布时间：2018-08-02 13:54

【摘要】：针对水泥环脆性较高,在固井后的施工作业中其完整性易遭受破坏的问题,将用太古油改性的EVA(乙烯醋酸乙烯酯共聚物)作为增韧材料加入油井水泥中,研究了其对油井水泥浆体系常规性能和力学性能的影响,分析了其对水泥石力学特性的影响机理。结果表明,改性EVA与水泥浆的相容性较好,其对浆体的流动性、失水量影响较小,水泥浆稠化时间随改性EVA掺量增加而延长;改性EVA对水泥石抗压强度影响较小,但能提高水泥石的抗折强度和韧性,当改性EVA加量为3%时,水泥石75℃养护3 d的抗折强度提高4.4%,压折比减小28.0%,掺量为4%时,水泥石弹性模量降低39.5%。改性EVA水解产物和水泥水化产物相结合,生成的晶体和脱水聚合物使水泥石内部结构更加致密,减小或消除了水泥石内应力集中,阻止了裂缝扩展,改善了水泥石的力学特性。
[Abstract]:In view of the high brittleness of cement ring and the easily damaged integrity of cement after cementing, the EVA (vinyl acetate copolymer) modified by Swire oil was added to oil well cement as toughening material. The influence of the cement slurry on the conventional and mechanical properties of the cement slurry system was studied, and the mechanism of its influence on the mechanical properties of cement paste was analyzed. The results show that the compatibility of modified EVA with cement slurry is better, the influence of modified EVA on the fluidity and water loss of cement paste is small, the thickening time of cement slurry is prolonged with the increase of modified EVA content, and the influence of modified EVA on compressive strength of cement stone is small. However, the flexural strength and toughness of cement stone can be improved. When the content of modified EVA is 3, the flexural strength of cement stone curing at 75 鈩，

本文编号：2159651