迪那2气田天然气处理工艺优化研究

Optimization study of natural gas process unit in Dina 2 gas field

迪那2凝析气田天然气处理采用J-T阀+乙二醇抑制剂低温冷冻分离工艺,设计单套处理量400×104 m3/d、制冷温度-20℃,投产后进站温度由设计的45℃升至65℃,乙二醇加注量不能满足设计制冷温度的要求,低温分离器频繁发生冻堵,单套处理能力限制在200×104m3/d、制冷温度-15℃。利用HYSYS软件对脱水脱烃装置进行模拟优化,确定天然气饱和水增加是造成装置冻堵的原因,制定了装置适宜运行参数表,避免装置发生冻堵,提出了分水器改造建议,实施后脱水脱烃装置达到设计参数,大幅度提高了液化气和轻烃产量,减少了乙二醇损耗,并提出了凝析气先空冷再分离的标准气处理工艺。

J-T valve＋ethylene glycol low temperature freezing separating process was adoptedto separate water and hydrocarbon of natural gas, and prevent hydrate formation by ethylene gly- col in Dina 2 gas field. The design capacity of a single set is 400×104 m3/d and the design refrige- ration temperature is --20 ℃. When the plant started production, the feed gas temperature raised from 45 ℃ to 65 ℃. The ethylene glycol dosage was too small to prevent the hydrate for- mation under the design refrigeration temperature, and the hydrate formed in the LT separator frequently. The process capacity was restricted to 200×104 m3/d, and the refrigeration tempera ture was 15 ℃. In this paper, the simulation and optimization of the dehydration and dealkyla- tion unit was studied by HYSYS software. The increasing saturated water of feed gas resulted in the hydrate formation. The appropriate parameters table was set out, which helped to prevent hydrate formation. The process capacity of dehydration unit meets the requirement of design pa- rameter after the installation of water separator. The yield of LPG and light hydrocarbon are im- proved significantly while the loss of ethylene glycol was decreased. The standard gas process was proposed for condensate gas, which flow into air cooler first then by water separator.