克拉美丽气田天然气烃水露点控制工艺改造

克拉美丽气田天然气处理站烃水露点控制工艺采用J-T阀节流制冷,注乙二醇防冻的低温分离工艺,但其外输天然气烃水露点出现不稳定、不合格现象。应用HYSYS软件根据天然气处理流程的物料及能量平衡评价烃水露点控制工艺,结果为:高压节流注醇工艺选择合理;通过对其核心设备包括低温分离器和气-气换热器结构及工作性能分析,找出烃水露点不合格的主要原因是低温分离器和气-气换热器选型不合理。根据克拉美丽天然气处理站烃水露点不合格原因提出了改造方案:沿用高压节流注醇工艺,其关键设备选型采用两台管壳式换热器(固定管板式)串联+SMMSM高效分离器的组合方案,将外输天然气烃水露点计算值控制在-13℃左右,考虑低温分离器与烃水露点的实际温差,可控制外输气烃水露点能达到小于-5℃的要求。

Technology transformation of hydrocarbon and water dew point control process in Kelameili gas field

The hydrocarbon and water dew point control process of natural gas treatment plant in Kelameili gas field adopts a low temperature separation process by J-T valve refrigeration and glycol antifreezing, but hydrocarbon and water dew point of the transported natural gas is unsta- ble and unqualified. According to material and energy balance of natural gas, HYSYS software is used to evaluate hydrocarbon and water dew point control process. The results show that process selection is reasonable. Based on the analysis of structure and working performance of core equip- ments including low temperature separator and gas-gas heat exchanger, the main reason of hy- drocarbon and water dew point unqualified is the unreasonable selection of low temperature sepa- rator and gas-gas heat exchanger. A transformation scheme is proposed： the high pressure throt tie technology is continued to use; the key equipment selection involves two tube and shell heat exchanger （fixed tube plate） series＋SMMSM high efficiency separator, and the calculation value of hydrocarbon and water dew point of transmission natural gas is controlled at --13 ℃ or so. Considering of the temperature difference, the hydrocarbon and water dew point can be decreased to less than -5℃.