榆林气田新旧低温分离工艺的对比分析

榆林气田天然气中含有微量凝析油，在管输中有液态烃析出，不能满足下游用户的要求。为彻底解决该问题，先后在榆总站建设了两套大面积换热、节流、低温分离工艺装置，并在现场进行了工业性试验。试验从换热效果、装置所用的甲醇量、外输的烃露点等方面进行，取得了技术上的成功。为此，对新旧低温分离工艺运行参数以及换热器的性能等进行了对比分析，在相同的压差下，管翅式换热器比板翅式换热器的换热效果更好，且运行费用低，操作难度降低。同时，在节流后一定的温度条件下，需要的节流阀前后的压差较小，说明低温分离工艺不仅能合理利用天然气自身的能量，而且对微含凝析油气田的地面工艺具有借鉴意义。

ANALYSIS ON NEW AND OLD LOW TEMPERATURE SEPARATION TECHNOLOGIES OF YULIN GAS FIELD

The natural gas produced from Yulin gas field contains slight amount of gas condensate. Thus, hydrocarbon liquid will be separated out during pipeline transmission, which can not meet the requirement for downstream users. To completely solve the problem, two set of heat exchange, throttling, low temperature separation (LTS) units are built on the general Yulin gas plant. Meanwhile, industrial tests were done in situ. The tests were carried out in terms of heat exchange performance, methanol consumption and dew point of hydrocarbon with great success. At the same time, a comparison was drawn between the operation parameters of the new and old LTS units and the performances of heat exchangers. The results showed that under the same pressure condition, the heat exchange performance of tube fin exchanger was better than that of plate fin exchanger, which also had lower operation cost and was much easier for operation. Meanwhile, pressure difference required before &; after the choke valve was lower while the after choke temperature was fixed. It proved that LTS technology can not only make full use of the energy of natural gas, but also be taken as reference for surface technology of gas field with slight content of gas condensate.