50 / 2025-11-20 11:36:13

受煤粉堵塞裂隙的表面活性剂疏通机理与调控规律/Surfactant-Induced Unclogging and Flow Mechanism for Coal Fines-Clogged Fractures

Keywords: Hydraulic fracturing; Viscoelastic surfactant (VES); Molecular dynamics simulation; Wettability; Coal fines clogging

【摘 要】为破解煤粉堵塞裂隙导致的裂缝导流能力衰减难题，本研究聚焦于黏弹性表面活性剂（VES）对煤粉的疏通机理与调控规律。研究通过自建的可视化运移实验平台、分子动力学模拟与界面表征，系统揭示了VES调控煤粉运移行为的双重机制：其一，VES分子通过形成特定胶束结构吸附于煤体表面，动态调控界面水层结构与运移行为，实现润湿性由疏水向亲水的根本转变；其二，VES溶液独特的粘弹性及其对流速的响应行为，在流动过程中通过调整粘滞力与剪切力，显著增强了压裂液对煤粉的携带与启动效率；与此同时，其极性基团吸附可有效调控界面Zeta电位，通过增强颗粒间静电斥力促进煤粉分散。上述界面改性与流场调控的协同作用，共同构成了VES压裂液的核心疏通机理。本研究阐明的机理与规律，为设计高效VES压裂液、根治煤粉堵塞提供了坚实的理论基石。

Abstract: To address the issues of reduced fracture conductivity and diminished gas extraction efficiency caused by coal fines accumulation during coal seam hydraulic fracturing, this study investigates the mechanisms of viscoelastic surfactant (VES) fracturing fluids at the coal solid-liquid interface, targeting the limitations of conventional fluids in wettability adjustment and fines-carrying capacity. Through a self-designed visual coal fines migration system, molecular dynamics simulations, and wettability characterization experiments, this study systematically investigated the dynamic relationships among VES micellar structure, interfacial properties, and coal fines migration. The results demonstrate that VES molecules, adsorbed on the coal surface in specific micellar configurations, can regulate the transport behavior of water molecules and significantly enhance the hydrophilicity of the coal interface. Furthermore, the adsorption of polar VES molecules alters the interfacial Zeta potential, increasing electrostatic repulsion and thereby promoting the dispersion of coal fines particles. This dual mechanism effectively mitigates coal fines clogging and enhances fracturing performance, providing a theoretical foundation for optimizing VES-based fracturing fluids.