塔河油田碳酸盐岩缝洞型油藏气水复合驱技术

塔河油田碳酸盐岩缝洞型油藏经水驱在高部位形成了大量的“阁楼油”，而用氮气驱替“阁楼油”时，由于横向驱动作用弱，在井间富集了大量剩余油。为此，根据塔河油田碳酸盐岩缝洞型油藏储层特征及剩余油分布特征，进行了气水复合驱技术研究。在利用物理模拟试验分析气水复合驱油机理的基础上，根据剩余油分布特征，构建了气水复合驱开发模式；根据井间连通通道的特征，设计了开发井网；利用历史水驱数据和累计注气量，设计了气水复合驱参数。塔河油田4区7个注采井组应用了气水复合驱技术，井组产油量平均增加80.0 t。这表明，气水复合驱中的气驱首先将“阁楼油”驱替到水驱通道，水驱提供横向驱动力再将其驱出，从而提高了剩余油的动用程度。 

Gas-Water Composite Flooding Technology for Fractured and Vuggy Carbonate Reservoirs in Tahe Oilfield

After water flooding, a large amount of “attic oil” will be left in the structural top of fractured and vuggy carbonate reservoirs in the Tahe Oilfield. Due to weak lateral drives, a large amount of remaining oil will be accumulated between wells even with nitrogen flooding. According to the reservoir characteristics and remaining oil distribution features of such reservoirs, a gas-water composite flooding technology was studied. Based on the analysis of gas-water composite flooding mechanisms, different gas-water composite flooding development modes have been established according to the distribution features of remaining oil. Based on the characteristics of inter-well communication pathways, the development well pattern was designed taking into consideration the unique conditions, and gas-water composite flooding parameters were designed from historical water flooding data and the cumulative gas injection volume. The gas-water composite flooding technology was applied in 7 injection-production well group of Block 4 of the Tahe Oilfield, and the oil production of this well group was increased by 80.0 tons on average. The results indicate that gas flooding in the gas-water composite flooding drives the “attic oil” to the water flooding channel first, and then the water flooding provides lateral driving force to transport it out.