Abstract: Organic salt drilling fluids are widely used in Kuqa piedmont of the Tarim basin and have achieved significant results. But the compatibility between the organic salt drilling fluid and cement slurry is very poor, seriously affecting the cementing safety. Therefore, some research and developing work have been done. First of all, by analysis means of Fourier transform infrared spectroscopy ( FTIR) , environmental scanning electron microscopy ( SEM) and X-ray diffractometer ( XRD) , as well as combined with hydration dynamic adsorption theory of clay, the effects of drilling fluid additives ' molecular structure and clay hydration mechanism on the hydration process of cement slurry were investigated to obtain the contact contamination mechanism of drilling fluid and cement slurry. On the basis of this, the relationship between the amount of anti-pollutant and the thickening time and rheology of the mixed slurry was established to study the essence of how anti-pollutant eliminated contamination to the mixed slurry. Finally, combining on-site slurry anti-pollution performance evaluation with theoretical results indicate that hydrated Ca2 + in the cement slurry compresses the diffuse electric double layer of the clay and causes the colloidal particles to coagulate. Meanwhile, the fluid loss agents in organic salt adsorbe moisture in the slurry, resulting in early slurry coagulation. The combination of the both results in slurry thickened. When mixed with anti-contaminant, the microstructure of the slurry is dense, and no new cement hydration produced, which can effectively eliminate the contact contamination between the two. Through the systematic study in this paper, it provides a new method to evaluate the contact contamination mechanism of cement slurry and organic salt drilling fluid as well as additives used to reduce contact contamination for both of them. In addition, it also provides an important scientific analysis basis to avoid the complicated situations during cementing while organic salt drilling fluid used.

摘要： 有机盐钻井液在塔里木山前大量应用并取得显著成效。但有机盐钻井液与水泥浆两者相容性极差，严重影响固井安全。为此，文章基于单因素分析方法，筛选出影响水泥浆流动度变差的钻井液外加剂类型，并借助傅里叶变化红外光谱仪、环境扫描电子显微镜及 Ｘ射线衍射仪，结合黏土水化动态吸附理论，探究钻井液外加剂分子构型、黏土水化机理对水泥浆水化过程的动态影响，以获得钻井液与水泥浆接触污染的本质。在此基础上，通过在钻井液中添加不同加量的降污染剂，探讨降污染剂合理加量对钻井液与水泥浆混合浆体稠化时间与流变性影响，并应用扫描电镜与用 Ｘ射线衍射仪分析结果，探究降污染剂加入能解除混合浆体发生污染的实质。通过系统研究，为有机盐钻井液条件下水泥浆污染诱导机理及采用降污染剂来解除两者的接触污染提供了评价新途径，为避免有机盐钻井液条件下固井施工井下复杂情况的发生奠定了重要的科学分析依据。

关键词: 接触污染, 水泥浆, 有机盐钻井液, 降污染剂, 机理研究