甲基硅酸钾页岩抑制剂的性能评价与作用机理

通过线性膨胀实验、膨润土造浆实验以及热滚回收实验对甲基硅酸钾的页岩抑制性能进行了评价。结果表明,甲基硅酸钾具有优异的页岩抑制作用,明显强于目前油田常用的另一种有机硅类页岩抑制剂——甲基硅酸钠。此外,通过X射线衍射、红外光谱以及水接触角测定等表征手段对甲基硅酸钾的抑制机理进行了分析。研究结果表明,甲基硅酸钾的黏土水化抑制作用来自钾离子和甲基硅酸根阴离子的协同作用。甲基硅酸根阴离子能够吸附在蒙脱石颗粒的边、角位,使原本相对亲水的蒙脱石颗粒表面转变为相对疏水,从而阻止水向蒙脱石层间的侵入,起到抑制膨润土水化膨胀的作用。

Performance and Functional Mechanism of Potassium Methylsiliconate as Shale Inhibitor

This paper evaluated the inhibition performance of potassium methylsiliconate as shale inhibitor in drilling fluids through linear swelling tests, bentonite inhibition tests and hot rolled dispersion tests. The results show that potassium methylsiliconate exhibits a high inhibition on hydrated swelling of shale. The performance is distinctly superior to sodium methylsiliconate, which is a traditional shale inhibitor in the oil field. The inhibition mechanism of potassium methylsiliconate was investigated by means of a variety of methods, including Fourier transform X-ray diffraction, infrared spectroscopy, and water contact-angle determination, et al. The outstanding inhibition of potassium methylsiliconate is derived from the synergy of potassium cations and methylsiliconate anions. Methylsiliconate anions can form a hydrophobic region surrounding the individual montmorillonite particle through the adsorption on the edge sites, thus inhibiting the ingress of water into the interlayer.