基于OLGA软件的湿气管道清管动态分析

中国石油集团工程设计有限责任公司北京分公司

China Petroleum Engineering Co. Ltd. Beijing Company

某原油处理厂的伴生气增压后输送到天然气处理厂,接收端气液两相分离器仅能处理正常运行时管道内产生的液体,不能接纳清管时产生的液塞。为了使接收端分离器可以在清管时正常运行,采取清管前管道减压、增加气量吹扫的方法减少管道内积液量,由于操作压力和气量选择不合理,清管前后分离器未能正常工作。利用OLGA 软件模拟了管道内积液量、分离器进液量随管道压力和入口气体流量变化的动态过程,得到了合理吹扫方案:降低管道操作压力,待管道内积液量平稳后提高入口气体流量,管道内积液量小于分离器处理能力时开始清管,该方案保证了清管前后接收端分离器的正常运行。

Associated gases from an oil treatment plant are transported to a gas processing plant after pressure boosting. The terminal gas-liquid separator can only be used to treat liquids produced in pipeline during normal operation, but not receive pigging slug. In order to make separator work properly during pigging operations, pipeline pressure is reduced and gas flowrate is increased to blow the liquid out of the pipeline to reduce the volume of fluids accumulated in the pipeline. However, due to improper operation pressures and gas volumes, the separator fails to work properly before and after pigging operations. By using OLGA, the dynamic process that volumes of fluids accumulated in the pipeline and volumes of feeding liquids in the separator change with pipeline pressures and flow rates of gases at inlet is simulated to highlight the optimal pipeline purging program. As first step in the program, operation pressure of the pipeline is reduced; then, the inlet gas flowrate is increased once the volume of liquids accumulated in pipeline become stable. Pigging operation is initialized when the volume of fluids is lower than the processing capacity of the separator. The proposed program can ensure proper functioning of separator at the receiving terminal before and after pigging operations.