硅酸盐钻井液防塌机理研究

基于电位、粒径分布、红外稳定性、压力传递和吸附量等测定方法,对硅酸盐钻井液的防塌机理进行的研究结果发现,无机盐类型和浓度以及pH值是硅酸盐粒径分布的主要控制因素,通过影响硅酸盐粒径分布从而影响硅酸盐钻井液的防塌效果,适当的无机盐也有利于协同防塌。通过压力传递实验研究发现,硅酸盐钻井液阻缓压力传递的效果显著,诱导的化学渗透压力效果也非常明显,其膜效率高。这也从另一个侧面反映了钻井液的强封堵能力可能源于在井壁上所形成的硅酸盐与页岩作用的膜,用实验验证了硅酸盐钻井液能够在极短时间内有效封堵井壁。

Study on anti-collapse mechanism of silicate drilling fluid

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.