可再分散乳胶粉对低温固井水泥浆性能的影响

Effect of Re-dispersible Powdered Latex on Properties of Low Temperature Cement Slurry

对比分析了添加可再分散乳胶粉前后低温固井水泥浆常规性能、渗透率、界面胶结强度以及微观形貌的变化。实验结果表明,可再分散乳胶粉能显著降低水泥石渗透率,提高界面胶结强度,加量为4.0%时,渗透率降低了94.2%,一、二界面胶结强度分别提高了66.4%、84.1%;通过微观形貌分析可以看出,可再分散乳胶粉能改善水泥石本体、界面处微观结构,使其更加致密、平整。乳胶粉加量小于3%时,对水泥浆稠化时间、流动度、抗压强度等常规性能影响较小,加量大于3%时,有一定增稠、缓凝、延缓强度发展现象。

Effects of re-dispersible powdered latex of the properties low temperature cement slurry were studied.It is found that the permeability of set cement can be remarkably reduced by adding re-dispersible powdered latex into the cement slurry,the bond strength of the interface between set cement and casing string/borehole wall at the same time is increased.At concentration of 4.0%redispersible powdered latex,the permeability of the set cement is reduced by 94.2%,while the bond strengths of the interfaces between set cement and casing string/borehole wall are increased by 66.4%and 84.1%,respectively.Addition of the re-dispersible powdered latex improves the micro-structure of the set cement and the interfaces,making them denser and smoother.At concentrations of less than 3%,the latex has less effect on the thickening time,mobility and compressive strength of the set cement.At concentrations greater than 3%,the latex to some extent viscosifies the cement slurry,and retards the development of the strengths of the cement slurry.