聚合物对油井水泥石微观结构和抗腐蚀性能的影响

Effect of polymer on the microstructure and resistance to corrosion of oil well cement stones

将不同组成的油井水泥石放在高温高压的酸性环境中腐蚀1~4个月,观察其腐蚀深度和微观结构变化。结果表明,在同一腐蚀时间内,苯丙胶乳水泥石和环氧树脂水泥石的腐蚀深度小于空白水泥石,腐蚀部分的水化产物受到溶蚀,硫含量增加;但水化产物组成没有变化,也未生成硫化物或碳酸盐。水泥石被腐蚀的原因可能是S^(2-)和CO_3^(2-)酸性离子被吸附于CSH内部,导致水化产物溶蚀。

Oil well cement stones with different polymer modifier were corroded in an acidic environment under high temperature and high pressure for 1 to 4 months. Their corrosion depths and the microstructural change were studied. The results proved that the corrosion depths of styrene acrylic latex cement stone and epoxy resin cement stone were smaller than that of bland cement stone after an equal time of corrosion. Hydration products were leached and the sulfur content increased significantly in the attacked region of cement stone,while the composition of hydration products was not changed. Sulfides and carbonates were not found. The corrosion mechanism may be that S^2-and CO3^2-was absorbed in CSH,resulting in a leaching of hydration products.