萨中开发区下返机械封堵工艺改进及现场试验研究

Research on improvement and field test of downward mechanical plugging technology in Sazhong Development Zone

2000年至今,大庆萨中开发区主要使用上下返封堵技术实现二类油层的化学驱返层开发,针对下返机械封堵工艺应用过程中暴露出的注入井桥式管柱作业难度大、密封可靠性差、采出井无法验封等问题,优化注入井桥式封堵管柱结构,设计一体化结构双管,大幅降低作业难度,连接效率提高61.1%。现场试验73口井,并选择其中35口井进行同位素吸液剖面测试验证,密封有效率达100%;设计采出井验封器,在封堵管柱上建立验封通道,通过下入专用验封对接器验封。现场试验结果表明,改进后的下返机械封堵工艺,解决了注入井、采出井下返机械封堵管柱存在的问题,可满足化学驱返层开发使用要求。

Since 2000,the Sazhong Development Zone in Daqing Oilfield has mainly used the upward and downward flowback plugging technology to realize the chemical flooding flowback development for the secondary oil reservoirs.Due to the difficulty existed in the operation of bridge-type string during the application of the downward mechanical plugging technology in the injection wells,poor sealing reliability,and unable inspection in the production wells,the bridge-type plugging string structure in the injection wells was optimized,and the integrated double-pipe structure was designed,which greatly reduced the difficulty of operation and increased the connection efficiency by 61.1%.73 wells were tested at site,and 35 wells were selected for isotope liquid absorption profile testing and verification,whose sealing efficiency reached 100%.The sealing test device in the production wells was designed,and the sealing channel in the plugging pipe was established,which was checked the sealing by running the special docking device.The field test results showed that the improved downward mechanical plugging technology could solve the problems existed in the downward mechanical plugging string of injection wells and production wells,which could meet the development requirements of the chemical flooding flowback development.