提高三元复合驱现场应用效果的技术途径

双河油田IV5~IV11层系油藏温度81 ℃、原油黏度3.3 mPa·s、综合含水97.9%、采出程度53.3%，呈现出典型的东部老油田水驱低效益开发特征。为了改善IV5~IV11层系开发效果、大幅度提高采收率，集成应用了驱油效率高的三元复合驱技术、扩大波及体积的层系重组井网调整技术和防止窜流的化学驱全过程调剖技术。室内研究和现场应用效果表明，3项关键技术产生多种协同效应，在扩大波及体积的基础上大幅度提高了驱油效率，取得优异的增油降水效果。截至2017年12月，IV5~IV11层系累计注入0.72 PV化学体系，累计增油26.09×10⁴ t，中心区峰值含水由97.9%降至90.2%，日产油由23.0 t升至106.1 t；阶段提高采收率10.2%，预计最终提高采收率14.2%。

Technical Approach for Improving the Field Application Result of ASP Flooding

The IV5~IV11 of Shuanghe Oilfield exhibit a temperature of 81℃, crude oil viscosity of 3.3 mPa·s, comprehensive water cut of 97.9%, and recovery rate of 53.3%, all of which manifest as typical characteristics of inefficient exploitation of aged oilfields by water flooding in eastern China. To improve the exploitation efficiency of the above-mentioned gas reservoirs and significantly increase their recovery rates, three key technologies were applied in conjunction, namely, the alkaline-surfactantpolymer(ASP) flooding with high displacement efficiency, well pattern arrangement for layer reconstruction with expanded swept volume, and profile control throughout the chemical flooding process with channeling prevention. Laboratory experiments and field applications showed that the integration of these three technologies introduced multiple synergetic effects, as the oil displacement efficiency was substantially increased in addition to the expanded swept volume, resulting in an increase in oil production and a decrease in water cut. As of December 2017, a 0.72 PV chemical system was injected into the IV5~IV11 layer. Consequently, oil production increased by 26.09×10⁴ t, peak water cut at the central area dropped from 97.9% to 90.2%, and daily oil production rose from 23.0 t to 106.1 t. Furthermore, while the recovery rate was increased by 10.2% at this stage, it is expected to finally increase by 14.2%.