流量对高含水体系CO_2水合物生成过程的影响

Influence of flow rate on CO_2 hydrate formation process in high water content system

为了确定适宜的输送条件、保障管路的流动安全,在高压水合物循环实验环路装置上进行了高含水体系下CO_2水合物生成的实验,研究了管输流量对CO_2水合物生成及堵塞过程中诱导时间和压差等的影响。实验结果表明,在CO_2水合物大量生成前,流动引起的剪切作用能够很好地抑制CO_2水合物晶核的聚集,CO_2水合物大量生成时水合物颗粒会在短时间内快速形成并聚集在一起。体系流量对CO_2水合物生成诱导时间的影响可能存在临界值,流量高于临界值时,诱导时间缩短速率变大;低于临界值时,诱导时间缩短速率较小;水合物瞬时生成量在临界值附近最大。恒压高含水体系下CO_2水合物在大量生成至堵塞的过程中受流量的影响较小。

In order to determine the suitable transportation conditions and ensure the safety of pipeline flow,experiments on the formation of CO2 hydrate under high water-cut system were carried out on the high pressure hydrate circulation pipeline device,and the generation of CO2 hydrate was investigated.The influence of flow rate on induction time and differential pressure during the CO2 hydrate formation and clogging process were studied.The experimental results showed that the flowinduced shear force could inhibit the aggregation of CO2 hydrate particles well before the CO2 hydrate was generated in large amounts.When a large amount of CO2 hydrate was generated,the CO2 hydrate particles would rapidly form in a short period of time.As a result,there might be a critical flow rate for the influence of the CO2 hydrate formation induction time.When the system flow rate was higher than this critical value,shortening rate of induction time was bigger.When the system flow rate was lower than this critical value,shortening rate of induction time was smaller,and the instantaneous hydrate formation amount was the largest near the critical value.Under constant pressure and high water system,CO2 hydrate was less affected by flow rate during the process of its formation and plugging.