天然气-凝析液混输管道水合物防控策略经济性研究

Economic Study on Hydrate Prevention Strategies of Natural Gas-Condensate Multi-Phase Flow Pipeline

天然气多相混输管道停输后,水合物生成风险较高,采用泄压放空、加注甲醇或两者联合使用均能有效地防控水合物生成,但其经济性不同。针对南海某气田海底管道停输工况,在充分考虑平台操作实际约束的前提下,研究了联合运用泄压与注剂措施,并提出了经济成本计算模型,分析了不同防控策略的经济性及其影响因素。结果表明,不同策略之间的经济成本差异显著,单纯注剂法和单纯放空法均有可能成为经济性最佳的水合物防控策略,而"注剂-泄压"联合策略的经济性较差;具体的最佳防控策略与管道积水量、甲醇和天然气价格密切相关。

When the natural gas multi-phase flow pipeline is shutdown,the risk of gas hydrate is relative high and the blowout or/and methanol, which can be used to prevent the hydrate effectively, have different costs. For the shutdown operation of the subsea pipeline of natural gas field in South China Sea with practical constraints, the amounts of gas venting and methanol injecting of different pressures levels are studied, and the cost model is proposed to analyze the optimal costs and related factors.The results show that there are significant differences among the costs of different strategies, and any one of the two strategies of blowout and methanol is likely to be economically optimal when they are used separately,rather than together.The best strategy depends on the amount of the assembled water in the pipeline and the methanol and natural gas prices as well.