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Abstract：
In this study, a new polyionic polymer inhibitor, TIL-NH2, was developed to address the instability of shale gas horizontal wells caused by water-based drilling fluids. The structural characteristics and inhibition effects of TIL-NH2 on mud shale were comprehensively analyzed using infrared spectroscopy, NMR spectroscopy, contact angle measurements, particle size distribution, zeta potential, X-ray diffraction, thermogravimetric analysis, and scanning electron microscopy. The results demonstrated that TIL-NH2 significantly enhances the thermal stability of shale, with a decomposition temperature exceeding 300 °C, indicating excellent high-temperature resistance. At a concentration of 0.9%, TIL-NH2 increased the median particle size of shale powder from 5.2871 μm to over 320 μm, effectively inhibiting hydration expansion and dispersion. The zeta potential measurements showed a reduction in the absolute value of illite\'s zeta potential from -38.2 mV to 22.1 mV at 0.6% concentration, highlighting a significant decrease in surface charge density. Infrared spectroscopy and X-ray diffraction confirmed the formation of a close adsorption layer between TIL-NH2 and the illite surface through electrostatic and hydrogen bonding, which reduced the weakly bound water content to 0.0951% and maintained layer spacing of 1.032 nm and 1.354 nm in dry and wet states, respectively. Thermogravimetric analysis indicated a marked reduction in heat loss, particularly in the strongly bound water content. Scanning electron microscopy revealed that shale powder treated with TIL-NH2 exhibited an irregular bulk shape with strong inter-particle bonding and low hydration degree. These findings suggest that TIL-NH2 effectively inhibits hydration swelling and dispersion of shale through the synergistic effects of cationic imidazole rings and primary amine groups, offering excellent temperature and salt resistance. This provides a technical foundation for the low-cost and efficient extraction of shale gas in horizontal wells.
摘要：
在这项研究中,一种新的聚离子聚合物抑制剂，开发TIL-NH2是为了解决由水基钻井液引起的页岩气水平井的不稳定性。利用红外光谱技术综合分析了TIL-NH2对泥页岩的结构特征和抑制作用,核磁共振波谱,接触角测量，粒度分布，zeta电位,X射线衍射,热重分析,和扫描电子显微镜。结果表明,TIL-NH2显著增强了页岩的热稳定性,分解温度超过300°C，表明优异的耐高温性。在浓度为0.9%时，TIL-NH2使页岩粉的中值粒径从5.2871μm增加到320μm以上,有效抑制水化膨胀和分散。zeta电位测量显示，浓度为0.6%时，伊利石zeta电位的绝对值从-38.2mV降低到22.1mV，突出显示表面电荷密度的显着降低。红外光谱和X射线衍射证实了通过静电和氢键在TIL-NH2和伊利石表面之间形成了紧密的吸附层，将弱结合水含量降低到0.0951%，并在干态和湿态下保持1.032nm和1.354nm的层间距，分别。热重分析表明热损失显著减少，特别是在强烈结合的含水量中。扫描电子显微镜显示，用TIL-NH2处理的页岩粉末表现出不规则的块状形状，颗粒间结合强，水化程度低。这些发现表明TIL-NH2通过阳离子咪唑环和伯胺基团的协同作用有效抑制页岩的水化膨胀和分散。提供优异的耐温性和耐盐性。这为水平井页岩气的低成本高效开采提供了技术基础。
