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为研究油气混输管道中天然气水合物的形成和堵塞过程,采用自行设计的高压环道装置,以去离子水、柴油、天然气为管输介质,在含水率70%、液相初始流量2000 kg/h等条件下进行水合物堵塞实验。研究结果表明:实验时水合物在管道中各处同时生成,但初始生成量并不相同;在本实验含水率下,水合物主要在管道气相空间壁面和液相主体中生成;水合物的生成会导致管内流量降低,在未添加乳化剂的情况下,油水混合液会因流量的降低而产生分层,此时水合物颗粒集中分布在混合液下层,造成流体黏度和管段压降的急剧升高,进而引发管道堵塞。Abstract: In order to investigate the hydrates formation and plugging process in oil and gas transmission pipelines, a high pressure test loop was specially designed where natural gas hydrates were formed in diesel oil + water system with a water cut of 70% and an initial liquid flow rate of 2000 kg?h-1. The experimental results show that hydrates form simultaneously in the whole pipeline, but the initial formation quantities are different. Tube wall and liquid bulk phase are the two places where hydrates mainly form at the experimental water cut. Without emulsifier, the oil/water emulsion would separate at low flow rates. Hydrate particles would then distribute mainly in the lower liquid phase, which results in an incredible increase in the viscosity and pressure drop. Liquid stratification and the sharp increase in viscosity is the governing reason of plugging.
In order to study the process of formation and clogging of natural gas hydrate in oil and gas pipelines, a self-designed high-pressure loop device was used to transport the deionized water, diesel oil and natural gas into the pipeline. Under the condition of water content 70%, liquid initial flow 2000 kg / h and other conditions for hydrate clogging experiments. The results show that hydrates are formed simultaneously in the pipeline during the experiment, but the initial formation amounts are not the same. In this experiment, the hydrates are mainly formed in the wall of the gas phase space and in the liquid phase. The formation of hydrates Will lead to lower flow in the tube, without the addition of emulsifier case, the oil-water mixture will be reduced due to traffic stratification, this time hydrate particles concentrated in the lower liquid mixture, resulting in a sharp increase in fluid viscosity and pipe pressure drop High, and then lead to pipeline congestion. Abstract: In order to investigate the hydrates formation and plugging process in oil and gas transmission pipelines, a high pressure test loop was specially designed where natural gas hydrates were formed in diesel oil + water system with a water cut of 70% and an initial liquid flow rate of 2000 kg? h-1. The experimental results show that hydrates form simultaneously in the whole pipeline, but the initial formation quantities are different. Tube wall and liquid bulk phases are the two places where hydrates mainly form at the experimental water cut . Without emulsifier, the oil / water emulsion would separate at low flow rates. The Hydrate particles would then distribute mainly in the lower liquid phase, which results in an incredible increase in the viscosity and pressure drop. Liquid stratification and the sharp increase in viscosity is the governing reason of plugging.