关键词: 硅酸盐钻井液, 防塌机理, 硅酸盐粒径分布, 压力传递实验, 膜效率

Abstract: The investigation on anti-collapse mechanism of silicate drilling fluid showed that the types and concentration of inorganic salts and the pH value were the main factors affecting the anti-collapse mechanism of silicate drilling fluid and controlled the diameter of poly-silicate particles.Adding appropriate inorganic salts into the drilling fluid could enhance its anti-collapse effect.The experiment result indicated that the silicate drilling fluid could remarkably prevent the pressure transportation,while the induced chemical osmotic pressure was also distinct.The membrane efficiency was considerable high,which showed the degree of membrane integrity by the interaction of silicate and shale.The experiments proved that the silicate drilling fluid could effectively block the wellbore timely when the drilling fluid contacted with the wall of wellbore.

Key words: silicate drilling fluid, anti-collapse mechanism, silicate particle diameter distribution, pressure transportation experiment, membrane efficiency