高压天然气水合物生长动力学及浆体黏度特性

为探究油气混输管道中天然气水合物的生成及流动特性，得到实际混输管道天然气水合物浆液的安全运行规律。运用高压天然气水合物实验环路，进行了油水乳液体系天然气水合物浆液流动实验。通过控制变量法研究了不同初始压力、初始质量流量与加剂量对天然气水合物生成诱导时间、管内浆液表观黏度、密度以及水合物体积分数等的影响，结果表明：初始压力越高，水合物生成诱导时间越短，由初始压力5.3 MPa下的1.47 h缩短至6 MPa下的0.71 h,缩短了约51.7%,水合物在生成过程中反应越剧烈，不利于运输的安全；初始质量流量越大，水合物生成诱导时间越长，由初始流量895.3 kg/h下的0.76 h增加到1 414.6 kg/h下的0.90 h,增加了约18.4%,表观黏度波动幅度越小，运输过程越平稳安全；增大阻聚剂的加剂量对水合物诱导时间影响较小，但水合物大量生成阶段现象越平稳，水合物生成后管内水合物体积分数越小，浆液输送性越好；在流动过程中若流速下降，压降反而增加，则说明水合物体积分数的聚并很明显且管内浆液表观黏度很大，管道堵塞风险较大。

Growth Kinetics and Slurry Viscosity Characteristics of High Pressure Natural Gas Hydrate

In order to explore the formation and flow characteristics of natural gas hydrate in oil-gas mixed transportation pipeline, the safe operation law of natural gas hydrate slurry in actual mixed transportation pipeline was obtained. The flow experiment of natural gas hydrate slurry in oil-water emulsion system was carried out by high pressure natural gas hydrate experiment loop. The influence of different initial pressure, initial mass flow rate and dosage on the induction time of natural gas hydrate formation, apparent viscosity and density of slurry in the tube and the volume fraction of hydrate were studied by the control variable method, and the following important research conclusions were obtained: The higher the initial pressure is, the shorter the induction time of hydrate formation is, which is shortened by 51.7% from 1.47 h at the initial pressure of 5.3 MPa to 0.71 h at the initial pressure of 6 MPa. The more intense the hydrate reaction is during the formation process, which is not good for the safety of transportation. The larger the initial mass flow rate is, the longer the induction time of hydrate formation is, which increases by 18.4% from 0.76 h at the initial flow rate of 895.3 kg?h-1 to 0.90 h at the initial flow rate of 1414.6kg?h-1. The smaller the fluctuation range of apparent viscosity is, the more stable and safe the transportation process is. Increasing the dose of polymer inhibitor has little effect on the induction time of hydrate. However, the more stable the hydrate formation stage is, the smaller the volume fraction of hydrate in the pipe after hydrate formation is, and the better the transport of slurry. In the process of flow, if the flow rate decreases, the pressure drop increases, indicating that the aggregation of hydrate volume fraction is obvious and the apparent viscosity of the slurry in the pipe is large, which leads to a greater risk of pipeline blockage.