The mechanism of the hydrophobized poly(ethylene glycol) (PEG)/K⁺ system inhibiting shale hydration was studied by laboratory experiment. The inhibition performance was evaluated through cuttings hot-rolling dispersion, bentonite inhibition and contact angle tests. The inhibition became stronger as contact angle and PEG concentration increased. A modified cuttings hot-rolling dispersion experiment suggested that these molecular systems did not act through the thermally activated mud emulsion (TAME) mechanism. The interaction of the PEG/K⁺ with clay samples was investigated through adsorption studies and by Fourier transform infrared spectroscopy (FT-IR), X-ray diffraction (XRD) and thermogravimetric analysis (TGA). The adsorption isotherms showed that the presence of K⁺ increased the PEG affinity for the clay surface. This inhibition effect was accompanied by a reduction of the bentonite hydration with PEG adsorption, evidenced by FT-IR, TGA and differential thermogravimetric (DTG) curves. XRD patterns were conclusive in showing that the presence of K⁺ ions limited the expansion of the clay interlamellar region to only one PEG layer, and the terminal hydrophobic segments of the PEG chains turned out to be determinant in enhancement of the inhibitory efficiency. The cuttings hot-rolling dispersion was carried out on water-base drilling fluid with PEG/K⁺, which proved the inhibition performance of PEG/K⁺ in oil field drilling.

通过室内实验研究了疏水化聚乙二醇(PEG)/K ⁺体系抑制页岩水化的机理。缓蚀性能通过岩屑热轧分散、膨润土缓蚀和接触角试验进行评价。随着接触角和 PEG 浓度的增加，抑制作用变得更强。改进的岩屑热轧分散实验表明，这些分子系统不通过热活化泥浆乳液 (TAME) 机制起作用。通过吸附研究和傅里叶变换红外光谱 (FT-IR)、X 射线衍射 (XRD) 和热重分析 (TGA) 研究了 PEG/K ⁺与粘土样品的相互作用。吸附等温线表明，K ⁺增加了对粘土表面的 PEG 亲和力。FT-IR、TGA 和差示热重 (DTG) 曲线证明了这种抑制作用伴随着 PEG 吸附的膨润土水合作用减少。XRD 模式的结论表明，K ⁺离子的存在将粘土层间区域的扩展限制为仅一个 PEG 层，并且 PEG 链的末端疏水链段被证明是提高抑制效率的决定因素。对含PEG/K ^{+ 的}水基钻井液进行岩屑热轧分散，证明了PEG/K ⁺在油田钻井中的缓蚀性能。