Preventing hydrate crystallization in drilling fluid is the key to ensure the safety of deep water drilling. In this work, hydrate inhibition effect of nano-silica in deep water drilling fluids was measured and compared with the typical hydrate inhibitors containing KCl-PVP and EG-PVP. The three phase equilibrium and the formation kinetics of CH₄ hydrate in the drilling fluids were measured. The micro-morphological features of the formed hydrates were observed by SEM. Results showed that EG-PVP drilling fluid was found to have the best thermodynamic inhibition effect on CH₄ hydrate where the deviation of the equilibrium pressure in EG-PVP drilling fluid and pure water was initially 2 MPa as the temperature was below 5 °C and increased up to about 5 MPa when the temperature was 10 °C. Nano-silica had almost no thermodynamic inhibition performance on CH₄ hydrate. Kinetic measurements revealed that EG-PVP and KCl-PVP drilling fluids prolonged the hydrate nucleation to more than 48 h, but failed to remain the hydrate inhibition effect after aging tests. Nano-silica was unable to prolong the nucleation time, but was effective in reducing the initial hydrate growth rate and less affected by aging tests. SEM images revealed that nano-silica prevented phase separation in hydrate growth and induced the CH₄ hydrate to form a spongy-like structure which was fragile in agitated drilling fluid. Therefore, nano-silica could be viewed as a potential synergist of hydrate inhibitors.

防止钻井液中的水合物结晶是保证深水钻井安全的关键。在这项工作中，测量了纳米二氧化硅在深水钻井液中的水合物抑制效果，并与含有 KCl-PVP 和 EG-PVP 的典型水合物抑制剂进行了比较。测量了钻井液中CH _4水合物的三相平衡和形成动力学。通过扫描电镜观察形成的水合物的微观形貌特征。结果表明EG-PVP钻井液对CH _{4的热力学抑制效果最好。}EG-PVP 钻井液与纯水的平衡压力偏差在 5 ℃以下时最初为 2 MPa，当温度为 10 ℃时增加到 5 MPa 左右。纳米二氧化硅对CH ₄水合物几乎没有热力学抑制性能。动力学测量表明EG-PVP和KCl-PVP钻井液使水合物成核时间延长至48 h以上，但在老化试验后未能保持水合物抑制效果。纳米二氧化硅不能延长成核时间，但能有效降低初始水合物生长速率，受老化试验影响较小。SEM 图像显示纳米二氧化硅阻止水合物生长中的相分离并诱导 CH ₄水合物形成海绵状结构，在搅拌的钻井液中易碎。因此，纳米二氧化硅可被视为水合物抑制剂的潜在增效剂。