流花19-5气田停输再启动水合物防控方案研究  

A Study on Hydrate Prevention and Control Plan for Shutdown and Restart Process of LH 19-5 Gas Field*

作　　者：陈海宏 姚海元 李清平 吴和金 CHEN Haihong;YAO Haiyuan;LI Qingping;WU Hejin(State Key Laboratory of Offshore Nature Gas Hydrate;CNOOC Research Institute Co.,Ltd.;Hainan Branch,CNOOC(China)Co.,Ltd.)

机构地区：[1]海洋天然气水合物全国重点实验室 [2]中海油研究总院有限责任公司 [3]中海石油(中国)有限公司海南分公司

出　　处：《油气田地面工程》2025年第1期1-8,共8页Oil-Gas Field Surface Engineering

基　　金：北京市科技新星计划项目“深水海底管道水合物堵塞早期预警技术研究”(20240484721);国家重点研发计划课题“深水多相流动安全监测与智能化决策技术”(2022YFC2806201);国家自然科学基金联合基金重点支持项目“深水油气及水合物开采过程中水合物堵塞监测及控制机理研究”(U21B2065);中海石油(中国)有限公司科研课题“深水混输管道堵塞预测及防控关键技术研究”(KJGG2022-0205)。

摘　　要：流花19-5气田包括两口水下生产井A1H、A2H,一个水下管汇,一条11.8 km的双层海管。在面临台风等极端天气条件时,气田水下生产系统一般需关停一周,而长时间停输会导致停输再启动过程中集输管路易生成水合物,影响水下生产系统安全运行。为了在保障气田安全生产的前提下实现降本增效,依托OLGA软件进行多相混输管道流动过程模拟,选取夏季与冬季典型工况,对流花19-5气田停输再启动水合物生成风险展开分析与评价,并提出了一套水合物防控最优方案。通过OLGA模拟发现,正常生产模式下流花19-5气田水下生产系统无水合物生成风险。夏季或冬季气田关停时,建议采用停输泄压至4 MPa作为海管水合物抑制方案,采用注入20%(质量分数)的甲醇富液作为A1H、A2H井筒、油嘴、跨接管水合物抑制方案。气田再启动时,夏季海管内注入甲醇富液浓度应高于20%,而冬季则应高于25%;A1H、A2H井筒内无水合物生成风险;A1H、A2H油嘴前甲醇富液注入浓度应分别不低于35%、40%;A1H、A2H跨接管甲醇富液注入浓度应分别不低于10%、25%。该研究结果可为流花19-5气田在台风模式下安全、经济生产提供参考。The LH19-5 Gas Field includes two underwater wells A1H and A2H,an underwater manifold,and an 11.8 km double-layer subsea pipeline.When facing extreme weather conditions such as typhoons,the underwater production system of the gas field usually needs to be shut down for a week,and a prolonged shutdown leads to the formation of hydrates in the gathering pipeline during the shutdown and restart process,which affects the safe operation of underwater production systems.In order to achieve cost reduction and efficiency increase on the premise of ensuring the safe production of the gas field,the flow simulation about operating the multiphase pipeline is carried out relying on OLGA software.The typical working conditions in summer and winter are selected to analyze and evaluate the risk of hydrate generation after the shutdown and restart of LH19-5 Gas Field,and an optimal scheme for hydrate prevention and control is proposed.Through OLGA simulation,it is found that there is no risk of hydrate formation in the underwater production system of LH19-5 Gas Field under normal production mode.When the gas field is shut down in summer or winter,it is recommended to use"stop transmission and relieving pressure to 4 MPa"as the hydrate suppression plan for the subsea pipeline,and"injection 20%(mass fraction)methanol-rich liquid"as the hydrate suppression plan for A1H,A2H well,nozzle,and jumpers.When the gas field is restarted,the concentration of methanol rich liquid injected into the subsea pipeline should be higher than 20%in summer,and higher than 25%in winter.There is no risk of hydrate formation in the A1H and A2H wells.The injection concentration of methanol-rich liquid in front of A1H and A2H nozzles should be no less than 35%and 40%,respectively.The injection concentration of methanol rich liquid into A1H and A2H jumpers should be no less than 10%and 25%,respectively.The research results can provide reference for safe and economic production in the typhoon mode of LH19-5 Gas Field.

关 键 词：气田 天然气水合物 停输再启动 防控 

分 类 号：TE3[石油与天然气工程—油气田开发工程]