聚胺抑制剂黏度和阳离子度与页岩相对抑制率的关系

采用开环聚合反应制备了聚胺页岩抑制剂，考察了聚胺相对分子质量（运动黏度）和阳离子度，以及其在钻井液中的质量分数对其页岩抑制性能的影响，并采用XRD方法测定了聚胺处理前后黏土的层间距。结果表明，聚胺具有良好的页岩抑制性能，钻井液中聚胺质量分数越大，相对抑制率越高，经其处理后的黏土层间距先减小后趋于恒定；随着聚胺相对分子质量（运动黏度）的增加，相对抑制率先增大后略有下降，黏土层间距不断增大后趋于缓和；随着聚胺阳离子度的增加，相对抑制率先增大后趋于缓和，黏土层间距呈先快速增加后略有下降的趋势。聚胺运动黏度在304～1940mm²/s、阳离子度在0.750～3.603 mmol/g范围时可以基本满足页岩抑制剂的要求。

Relationship of Polyamine Viscosity and Cationic Degree to Relative Inhibitory Rate of Shale

Polyamine shale inhibitor was prepared by ring-opening polymerization, whose kinetic viscosity and cationic degree were determined. The clay lattice spacing before and after polyamine solution treatment was calculated through XRD analysis. The effects of kinetic viscosity and cationic degree, as well as the mass fraction of polyamine in drilling fluid on relative inhibitory rate of shale were investigated. Results showed that polyamine exhibited high performance of shale inhibition. With the increase of polyamine mass fraction in drilling fluid, the relative inhibitory rate enhanced, and clay lattice spacing first decreased and then kept constant. With the increase of relative molecular mass (kinetic viscosity) or cationic degree of polyamine, the relative inhibitory rate first increased and then decreased slightly, while lattice spacing first increased rapidly and then decreased slightly. The ranges of physiochemical index for polyamine application were obtained with kinetic viscosity of 304-1940 mm²/s and cationic degree of 0.750-3.603 mmol/g.