复合驱体系交替注入频次对化学驱效果的影响

INFLUENCES OF THE ALTERNATIVE INJECTION FREQUENCY AND TIME OF THE COMPOUND FLOODING SYSTEM ON THE CHEMICAL FLOODING EFFECTS

为了充分发挥三元复合驱体系各组分提高洗油效率和扩大波及体积作用,对三元复合驱体系注入方式进行了优化,由传统整体注入调整为碱/表面活性剂与聚合物交替注入。通过数值模拟和室内物理模拟驱油实验,在化学剂用量相同条件下,研究了交替注入频次对化学驱采收率的影响。结果表明,前置聚合物注入0.100倍孔隙体积时,交替注入频次为3-4次,驱油效果较好。现场情况表明,复合驱交替注入较好解决了整体注入注采能力下降幅度大、低渗透油层吸液能力差等问题,试验区的采出程度高出传统三元复合驱体系对比区7.8百分点。

In order to farthest improve the oil displaced efficiency and swept volume of each component of ASP flooding system, the injecting mode of the system has been optimized i. e. from the traditional overall injecting mode to alternative one between alkaline/surfactant and polymer. By numerical and indoor physical simulation experiments, under the condition of the same amount of chemical agents, the influences of the altemate injection frequency and time on the chemical flooding recovery are researched. The results show that 3-4 times, in another word, 0. 100 PV for A/ S system, can achieve much better effects. The field test shows that the compound alternative injecting mode can soundly and perfectly solve the following problems： serious drop degree of the injectivity for the overall injection mode, poorer liquid absorption capacity for the lowpermeability oil reservoirs and so on, the recovery degree of the test area is 7. 8% higher than that of the contrast block by the traditional ASP system.