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 unstable 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 equipments including low temperature separator and gas-gas heat exchanger, the main reason of hydrocarbon and water dew point unqualified is the unreasonable selection of low temperature separator and gas-gas heat exchanger. A transformation scheme is proposed: the high pressure throttle 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 ℃.