气井井下挂片腐蚀监测工艺研究及应用

Research and application of downhole coupon corrosion monitoring technology in gas well

关键词:  腐蚀监测  钢丝作业  投捞  冲蚀  流态  节流效应  室内试验  现场应用

Key words:  corrosion monitoring  wireline operation  throwout  erosion  flow regime  throttling effect  laboratory experiment  field application

摘要:

随着越来越多酸性气藏的开采,井下防腐及腐蚀监测日益重要。传统的井下挂片腐蚀监测是将腐蚀挂片安装在固定式油管短节内,挂片必须随油管一并入井和起出,监测深度固定,井下挂片腐蚀监测以及结果分析受限于修井作业时机。针对传统井下腐蚀监测缺点以及目前现场腐蚀监测需求,通过技术攻关研究,自主研发出一种用于气井井下腐蚀监测的工具。室内评价及现场试验表明,该工具性能可靠,实施方便,能更真实更直观地评价井下腐蚀状态,实用范围广,具有腐蚀监测深度调节方便、试片数量和类型可调等优点。现场成功应用为气井井下防腐以及选择合理的修井作业时机提供直接依据,大大降低了气井井下腐蚀监测成本,减少了大修作业,对气井安全生产也具有重要的意义。

Abstract:

As more and more mining of acidic gas reservoir, downhole corrosion prevention and corrosion monitoring are increasingly important. The traditional downhole coupon corrosion monitoring is to hang a piece of coupon installed inside a stationary tubing nipple, but the coupon must be into and up with the tubing in the well. Because the monitoring depth is fixed, the result and analysis of downhole coupon corrosion monitoring are limited by the workover job opportunity. Aiming at the faults of conventional downhole corrosion monitoring as well as the demand of current locale monitoring, a tool for gas well downhole corrosion monitoring was researched and developed independently. The result of indoor evaluation and field test indicated that the tool has the advantages of reliable performance and convenient implement, more real and intuitive evaluation of downhole corrosion, a wide practical range, as well as convenient adjustment for the depth of corrosion monitoring, adjustable number and type, etc. The successful application provides a direct basis for the downhole corrosion inhibition of gas wells and selecting reasonable workover job opportunity, greatly reduces the cost of downhole corrosion monitoring of gas well and overhaul operations, which has an important meaning for gas well safety production.