复杂地表气田集输管道的泡沫排液技术

针对气田集输管道易发的积液问题,将井筒中常用的泡沫排液技术创造性地应用至集输管道。通过环道测试、高速摄像、数据分析等方法探究发现,泡沫排液技术在起伏管道内表现出排液和减阻两种效果,并进一步研究了入口条件、管道起伏角度及发泡剂加注浓度等因素对上述效果的影响。试验发现:相比井筒,管道的起伏坡度更小,会影响管内泡沫的发泡程度,使流体的泡沫质量处于泡沫分散区或泡沫干扰区,而促使泡沫流体进入稳定泡沫区是保证泡沫排液技术在地面起伏管道内有效应用的前提。当工况为低含液率、大倾角起伏管道以及高于临界胶束浓度的加注浓度时,泡沫排液技术表现出更好的排液和减阻效果。建议现场作业改变原有的加注方式,提高发泡剂注入量,并采用有效手段提高地面起伏管道内流体的泡沫质量。

A foam drainage technology used in gathering pipelines under complex topographical conditions

Liquid loading tends to happen easily in the gas gathering pipelines of gas fields. To solve this problem, the foam drainage technology which is commonly used in the wellbore is creatively applied to gathering pipelines. In this paper, the effects of foam drainage technology in hilly pipelines were explored by means of loop test, high-speed camera and data analysis. It is shown that there are two effects, i.e., drainage effect and drag reduction effect. Then, the influences of inlet condition, pipeline undulation angle and foaming agent concentration on the drainage and drag reduction effects were analyzed. It is indicated from test that compared with wellbores, the foaming degree of foam in pipelines will be influenced by the smaller undulation slope of pipelines. In this case, the foam quality is in the foam dispersion area or the foam interference area. However, the prerequisite to guarantee the effectiveness of the foam drainage technology in hilly pipelines is to drive the foam fluid into the stable foam zone. The drainage effect and drag reduction effect are better when it is in the working conditions with low liquid holdup, large dip angle pipeline and foaming agent concentration higher than the critical micelle concentration. It is suggested to change the original filling method on site, improve the injection rate of foaming agent, and take advantage of the effective means to improve the foam quality of fluids in hilly pipelines.