气井泡排后气液分离不充分分析及措施研究

Analysis of the reasons separating liquid from gas inadequately when gas well form dewatering in gas field and the study on effective measurements

目前靖边气田在未采取泡沫排水采气措施的情况下,集气站气液分离状况良好,脱水撬运行平稳。但采取泡沫排水采气措施后,相应站内气液分离不够充分,严重影响脱水撬的高效、平稳运行。分析气液分离不充分的原因,并确定气液高效分离的措施对于提高靖边气田的开发具有重要意义。本文通过对生产动态与起泡剂和消泡剂作用特点的分析研究,以及对携液流动时间和破泡时间的分析计算,结合对丝网捕雾器液泛速度的分析,找到了气液分离不充分的原因:产量的波动导致携带泡沫液的天然气从进站加入消泡剂到进入分离器入口前的流动时间短于消泡剂的破泡时间,致使泡沫在破泡不够充分的情况下就进入了分离器;泡排后地层水变为泡沫液,密度大为降低,而破泡不充分使相对较多的残余液沫进入分离器中的丝网捕雾器,大幅降低了丝网的波泛速度,致使液沫容易被气流二次夹带。在对现场实际情况分析的基础上,提出了在泡沫排水采气措施后提高气液分离效率的措施与建议。

At present, liquid separates efficiently from gas without foam dewatering in Jingbian gas field. But, liquid can not separate adequatly from gas in the relevant gas gathering stations when foam dewatering, which badly influence efficient and smooth operation of the dehydrator. It is significant to analyse the reason why liquid separates inadequately from gas and propose effective measurements for improving the efficiency of separation of liquid from gas. By the composition analysis of production performance and the characteristics of the role of foamer and defoamer and the calculation and analysis of the defoaming times and flowing times of gas with liquid, In connection with the analysis of the flooding speed of mesh mist eliminator, the reason why liquid separates inadequatly from gas is found： wavy output induces that the time gas with foam liquid move from the entrance of gas gathering station, where the defoamer is placed into gas-liquid mixture, to the entrance of separator, is often shorter than the defoaming time, leading that foam enter mesh mist eliminator in separator without breaking enough; water turns to foam when foam dewatering, leading to its density decreasing substantially, at the same time , relatively more liquid foam entering the mesh mist eliminator in separator results in the flooding velocity decreasing substantially which brings on liquid foam re-entrainment. According to the field situation, effective measurements and suggestion are proposed for improving the efficiency of separation of liquid from gas when foam dewatering.