硅灰对油井水泥抗腐蚀能力的影响
EFFECTING ON ANTI CORROSION ABILITY OF OIL WELL SLURRY USING SILICA FLOUR
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摘要: 高矿化度地下水和高合CO2、硫酸盐还原菌的地下水,通过溶蚀、化学和膨胀对水泥石进行腐蚀,减低油井寿命。通过特性分析,认为改善水泥石的渗透性,降低水泥石中Ca(OH)2的含量,能从本质上提高水泥石的抗腐蚀能力。在水泥中加入一定比例的硅灰后,使水泥石中Ca(OH)2含量降低,另外,也改变了水泥体系的钙硅比和水化产物的组分,使水泥石结构均匀、致密、孔隙孔径变小、孔隙度降低,使水泥石强度增加,渗透率降低,从而提高了水泥石的抗腐蚀能力。Abstract: The ground water with high salinity,high CO2 content and ground water of sulphate reducing bacteria corrode the cement by dissolving,chemical and expansion actions.Analyzing results show that improving permeability of cement,reducing content of Ca(OH)2 in cement can improve the ability of anticorrosion.Adding silica flour in proportion into cement make content of Ca(OH)2 in cement reduce in addition to change proportion of calcium and silica and composition of hydrates.Homogeneity,tight,small pore channel and low permeability improve the strength of cement and anti-corrosion ability.