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

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.