柠檬酸对油井水泥的作用初探

柠檬酸是一种较强的有机酸，离解度较大，离解后的离子对水泥浆具有缓凝作用和分散作用，但柠檬酸的作用不仅如此，室内实验结果表胆，柠檬酸影响水泥石强度的发展，在中，低温情况下随着加量的增大，柠檬酸具有较强的缓凝作用，但在高温情况下，缓凝效果呈一条曲线，在加量大于0．8％时，表现为促凝，在各种温度下，柠檬酸对水泥浆都具有分散作用，对盐水水泥浆的分散作用尤其突出，柠檬酸能够改善水泥浆的析水量，然而柠檬酸易被各种氧化剂氧化，因此对不同水泥浆体系性能的影响不稳定，如果水泥外加剂中含有醇类，或体系温度过高，柠檬酸将发生反应并失去,但在中，低温情况下，性能比较稳定。

A discussion on the effect of citric acid on oil well cement performance

As one of the stronger organic acids, citric acid has a higher degree of dissociation, and the ions after dissociation can act as retardant and dispersant to the cement slurry system. The results of laboratory tests show that the citric acid can affect the strengthdevelopment of the cement. In the medium and low temperature, with the rise of its adding volume, it has obvious retarding effect; while in high temperature, the retarding efficiency appears as a curved line. When the volume is higher than 0. 8%, it acts as accelerating agent. Under various temperature conditions, the citric acid displays its dispersing effect to the cement slurry, especially in the salt-water cement slurry system. The citric acid can also improve the water extraction of the cement slurry. For the citric acid is easily get oxidized by many oxidant, its effect on different cement slurry system is unstable, for example, in the case of alcohol exists in the cement additives, or the temperature is too high, the citric acid will be reacted. Its performance is more stable under medium or low temperature conditions.