油井套管脉冲电流阴极保护在线监控装置研究应用

Research and Application of Online Monitoring Device for Pulse Current Cathodic Protection of Oil Well Casing

传统油井套管阴极保护技术存在着直流电流穿透地层能力差,保护套管电位不均匀、距离短,深井和超深井的套管末端得不到保护,经常发生套管腐蚀损伤等现象,结合智能化油田发展的需要,进行了油井套管脉冲电流阴极保护在线监控装置研究.重点介绍了油井套管脉冲电流阴极保护工作原理、组成以及在线监控装置设计方案.实际应用表明:采用脉冲电流送入套管外腐蚀井段方式,减缓了套管腐蚀速率,使较深井套管得到全线均匀保护,同时能在线监控油井套管脉冲阴极保护生产参数和远程操控阴极保护设备,实现无人值守.

The traditional cathodic protection technology for oil well casings has some problems,such as poor ability of DC current to penetrate the formation,short uneven distance of protective casing potential,unprotected casing ends in deep and ultra-deep wells,and frequent casing corrosion damage.In combination with the needs of the development of intelligent oil fields,the online monitoring device for oil well casing pulse current cathodic protection has been studied.The working principle,composition,and design scheme of online monitoring device for pulse current cathodic protection of oil well casing are emphatically introduced.The practical application shows that the pulse current is sent into the corrosion well section outside the casing can slow down the corrosion rate of the casing,make the casing in deeper wells uniformly protected throughout the entire line.At the same time,the pulse cathodic protection production parameters of the oil well casing can be monitored online and the cathodic protection equipment can be remotely controlled,achieving unattended operation.