Li Yutong, Zhang Fan, Wang Bo, Liu Jiaming, Wang Yu, Shi Zhengli, Du Leyao, Wang Kaiwen, Zhang Wangyuan, Wang Zonglun, Dou Liangbin
School of Petroleum Engineering, Xi'an Shiyou University, Xi'an 710065, China.
Shaanxi Yanchang Petroleum (Group) Co., Ltd., Xi'an 710069, China.
Gels. 2025 Aug 20;11(8):666. doi: 10.3390/gels11080666.
Polymers derived from renewable polysaccharides offer promising avenues for the development of high-temperature, environmentally friendly drilling fluids. However, their industrial application remains limited by inadequate thermal stability and poor colloidal compatibility in complex mud systems. In this study, we report the rational design and synthesis of epichlorohydrin-crosslinked carboxymethyl xylan (ECX), developed through a synergistic strategy combining covalent crosslinking with hydrophilic functionalization. When incorporated into water-based drilling fluid base slurries, ECX facilitates the formation of a robust gel suspension. Comprehensive structural analyses (FT-IR, XRD, TGA/DSC) reveal that dual carboxymethylation and ether crosslinking impart a 10 °C increase in glass transition temperature and a 15% boost in crystallinity, forming a rigid-flexible three-dimensional network. ECX-modified drilling fluids demonstrate excellent colloidal stability, as evidenced by an enhancement in zeta potential from -25 mV to -52 mV, which significantly improves dispersion and interparticle electrostatic repulsion. In practical formulation (1.0 wt%), ECX achieves a 620% rise in yield point and a 71.6% reduction in fluid loss at room temperature, maintaining 70% of rheological performance and 57.5% of filtration control following dynamic aging at 150 °C. Tribological tests show friction reduction up to 68.2%, efficiently retained after thermal treatment. SEM analysis further confirms the formation of dense and uniform polymer-clay composite filter cakes, elucidating the mechanism behind its high-temperature resilience and effective sealing performance. Furthermore, ECX demonstrates high biodegradability (BOD/COD = 21.3%) and low aquatic toxicity (EC = 14 mg/L), aligning with sustainable development goals. This work elucidates the correlation between molecular engineering, gel microstructure, and macroscopic function, underscoring the great potential of eco-friendly polysaccharide-based crosslinked polymers for industrial gel-based fluid design in harsh environments.
源自可再生多糖的聚合物为开发高温、环境友好型钻井液提供了有前景的途径。然而，它们的工业应用仍然受到热稳定性不足以及在复杂泥浆体系中胶体相容性差的限制。在本研究中，我们报告了通过共价交联与亲水性功能化相结合的协同策略开发的环氧氯丙烷交联羧甲基木聚糖（ECX）的合理设计与合成。当将ECX加入水基钻井液基浆中时，它有助于形成坚固的凝胶悬浮液。全面的结构分析（傅里叶变换红外光谱、X射线衍射、热重分析/差示扫描量热法）表明，双重羧甲基化和醚交联使玻璃化转变温度提高了10℃，结晶度提高了15%，形成了刚柔兼备的三维网络。ECX改性的钻井液表现出优异的胶体稳定性，ζ电位从-25 mV提高到-52 mV就证明了这一点，这显著改善了分散性和颗粒间静电排斥力。在实际配方（1.0 wt%）中，ECX在室温下使屈服点提高了620%，滤失量降低了71.6%，在150℃动态老化后仍保持70%的流变性能和57.5%的滤失控制能力。摩擦学测试表明摩擦降低高达68.2%，热处理后仍能有效保持。扫描电子显微镜分析进一步证实了致密且均匀的聚合物-粘土复合滤饼的形成，阐明了其高温弹性和有效密封性能背后的机制。此外，ECX表现出高生物降解性（生化需氧量/化学需氧量 = 21.3%）和低水生毒性（半数有效浓度 = 14 mg/L），符合可持续发展目标。这项工作阐明了分子工程、凝胶微观结构和宏观功能之间的相关性，突出了环保型多糖基交联聚合物在恶劣环境下工业凝胶基流体设计中的巨大潜力。
