泡排技术清除起伏管道积液试验

受地形影响，湿天然气集输及油气混输管道易在沿程起伏及低洼位置处形成积液。由于集输管道与气井倾角存在巨大差异，作为气井清除积液的成熟方式，泡沫排液技术无法直接应用于混输管道排液，其可行性需进一步论证。通过开展不同倾角下含泡沫气液多相管流试验，从流型转换、积液起塞机制的角度分析了管道倾角对含泡沫气液多相流动的影响。结果表明：在与气井倾角差异较大的低起伏管道中，能够通过添加表面活性剂的方式来清除积液，并对段塞流工况的发生起到较好的抑制作用。同时，通过在SDS表面活性剂溶液中添加NaCl、MgCl₂作为环境影响因素，利用金属网格传感器、高速摄像以及压力传感器，进一步探究无机盐条件下SDS水基泡沫排液效果。结果显示，无机盐引起的泡沫性能差异会对泡沫排液效果产生较大影响。，当管道内出现过量稳定泡沫时，会引起管道沿程压降显著增大。研究结果可为泡沫排液技术在集输管道中的应用推广提供指导与参考。

Affected by the terrain trend, wet natural gas gathering pipelines and multiphase flow pipelines are prone to accumulate liquid at the undulating and low-lying locations along the way, forming liquid accumulation. Due to the huge difference in inclination angle, as a mature way to remove liquid accumulation in gas wells, foam drainage technology cannot be directly applied to the drainage of hilly terrain pipelines, and its feasibility needs further demonstration. In this paper, experiments of gas-liquid multiphase pipe flow with or without foam at different inclination angles were carried out to analyze the influence of inclination angles and foam on gas-liquid multiphase flow from the flow pattern transition and slugging mechanism of liquid accumulation. The research results show that in hilly terrain pipelines with large difference in inclination angle from vertical gas wells, the liquid accumulation can be removed by adding surfactant, and the occurrence of slug flow can be well restrained. Meanwhile, by adding additional NaCl and MgCl₂ as environmental impact factors, using a Wire-mesh sensor, high-speed camera and pressure sensors, the liquid drainage effects of SDS aqueous foam in the presence of inorganic salts were further studied. The results show that the difference of foam performance caused by inorganic salts will have a greater impact on the liquid drainage effect of foam. In particular, when excessive stable foam exists in the pipeline, the pressure drop gradient will increase significantly. This study provides theoretical guidance and reference value for guiding the application of foam drainage technology in hilly terrain pipelines.