锦州20-2凝析气田海底管道改造复合清洗技术

Composite cleaning technology for Jinzhou 20-2 offshore pipeline reconstruction

锦州20-2凝析气田海底管道输送介质黑油含量较高,致使改造工程中海底管道的切割、回接存在安全隐患和残油污染海洋环境问题。设计了"双向直板型清管器+化学药剂清洗"的复合清洗工艺方案,并通过实验对化学清洗剂进行了确定,采用无毒、无污染的D-柠烯、AQ-11和AQ-12分别作为油溶性清洗剂、乳化剂和水溶性清洗剂。复合清洗工艺方案实施结果,海底管道排出液含油质量浓度低于30mg/L,达到了我国海洋污水排放标准,并且清洗液用量较少。

The conveyance medium of Jinzhou 20-2 condensate gas field submarine pipeline contains much more black oil, which could lead to the dangerous case in cutting or tie-back offshore pipeline in reconstruction and the ocean environment pollution. The composite cleaning technical project was designed as ＂double flow penhold pig plus chemical cleaning＂ and the chemical cleaning agent was confirmed by experiments. D-limonene, AQ-11 and AQ-12 cleaning agent were used separated as oilsoluble cleaning agent, emulsifying agent and water-soluble agent as a result of their non-toxic and freedom contamination. The testing results indicated that the oil content mass concentration in blowout fluid from Jinzhou 20-2 condensate gas field submarine pipeline was less than 30 mg/L which met the China sewage drainage standard in open sea, while less cleaning agent was used.