海底混输管道析蜡对水合物生成的影响

Effect of wax formation on hydrate precipitation in subsea multiphase pipeline

海底混输管道由于高压、低温的输送环境,蜡与水合物可能同时生成。采用水合物和蜡的热力学模型,从热力学角度分析蜡晶析出对水合物生成的影响。结果表明:轻组分的含量对水合物相界线影响显著,轻组分含量越高,水合物生成温度越高;蜡晶的析出会带走体系中的重组分,降低轻组分的溶解度,同时使轻组分的浓度增加,从而促进水合物的生成;由于蜡晶的析出对轻组分改变较小,析蜡对水合物生成的影响不显著。

In subsea multiphase pipeline,both wax and hydrate may form simultaneously due to the high pressure and the lowtemperature. The thermodynamic, models of wax and hydrate were selected to study the effect of wax formation on hydrate precipitation.The results show that the effect of the light end fraction on hydrate phase boundary is notable. The higher the lightcomponent content, the higher the hydrate formation temperature. The wax formation can carry away the heavy component inthe system, reduce the solubility of the light component and increase the concentration of the light component, which promotesthe hydrate precipitation. It is concluded that the effect of wax formation on the hydrate phase boundary is not notabledue to the little change of the light component by wax formation.