图版修正法水露点测量技术在海上气田的应用

Application of water dewpoint test method based on modified plate correction on offshore gas field

关键词:  水露点  三甘醇脱水  图版  贫三甘醇质量分数  接触塔

Key words:  water dew point  TEG dehydration  plate  lean TEG mass fraction  contact tower

摘要:

天然气水露点是衡量天然气质量的重要指标,鉴于传统水露点测量的不足,针对三甘醇脱水工艺,以接触塔出口平衡水露点、贫三甘醇质量分数及入口气温度的关系图为基础,提出了一种图版修正法水露点测量技术。测量前通过试验测试获得气田平衡水露点与实际水露点之间的偏差量。测量中通过采集三甘醇脱水系统中接触塔入口天然气温度以及贫三甘醇质量分数,代入已知的图版,获得平衡水露点,在平衡水露点基础上增加偏差量修正,获得测量水露点。为便于精确读图,开发出了测量软件。图版修正法水露点测量方法操作简便,测量精度高,在海上气田取得了良好的应用效果,可广泛推广使用。 

Abstract:

Water dew point is an important index for measuring if the external gas reached the standard. The traditional method to test water dewpoint of natural gas has lots of disadvantages. This paper proposes a new method based on modified plate to obtain the actual water dew point in the process of TEG dehydration system. The plate expresses the relationship between the inlet gas temperature and the lean TEG mass fraction and the outlet balanced water dew point in the contact tower. The deviation between the balanced dew point and the actual dew point should be obtained before the measurement. In the measurement the gas inlet temperature and the mass fraction of lean TEG were collected to substitute into the plate to obtain the balanced dew point, correct the result with the known deviation to get the actual dew point. In order to accurately find the corresponding points in the plate, a professional software was developed. The new method with software is easy to operate and the measurement error is small. The new method can be widely used in gas field.