永久式光纤监测技术在海上首口二氧化碳回注井的应用

Application of Permanent Optical Fiber Monitoring Technology in the First offshore Carbon Reinjection Well

近期南海东部海域恩平油田我国海上首口二氧化碳回注井正式投产,采油分离出来的二氧化碳气体被烘干压缩后回注至储层进行封存。为确保注入期间的安全性需要实时掌握注入参数判断井下情况,采用永久式分布式光纤监测技术,实现了全井筒温度剖面及井底压力的实时动态监测。现场应用结果表明:分布式光纤温度监测剖面与地层梯度测试温度剖面误差0.1%,光纤压力计监测结果与注入压力、地层压力误差0.05%,根据光纤数据监测的分布解释结果可反演二氧化碳回注剖面,从而指导注气参数动态调整。

The first offshore carbon dioxide reinjection well in Enping Oilfield in the eastern waters of the South China Sea has producted.The carbon dioxide gas separated from oil and is dried and compressed before being reinjected into the reservoir for storage.To ensure safety during injection,it is necessary to real time monitor the injection parameters to determine the underground situation,and permanent distributed fiber optic monitoring technology is adopted.achieving real-time dynamic monitoring of the entire wellbore temperature profile and bottom hole pressure.The on-site application results show that the error between the distributed optical fiber temperature monitoring profile and the temperature profile of the formation gradient test is 0.1%;,The error between the monitoring results of thefiber optic pressure gauge and the injection pressure and formation pressure is 0.05%.Based on the distribution interpretation results of thefiber optic data monitoring,the carbon dioxide reinjection profile can be inverted to guide the dynamic adjustment of gas injection parameters.