特高含水期油藏氮气驱提高采收率数值模拟研究

Numerical Simulation of Enhanced Recovery by Nitrogen Injection at the High Water-cut Stage

针对特高含水期油藏剩余油分布的复杂情况,以国内某区块为实例,进行了氮气驱的数值模拟研究。氮气和水的注入方式分两种:同时注入(类别A)和交替注入(类别B)。对预测的生产指标进行分析,得出最适合该区的方案为氮气和水交替半周期为15d、交替轮次为2次、单井注气量为6000m3/d。该方案比水驱方案提高采收率5.7个百分点。

In consideration of the situation of residual oil distribution at the high water-cut stage, by taking a block in certain oilfield for example, a numerical simulation on nitrogen displacement was conducted. There were 2 modes for nitrogen and water injection, including injection of both at the same time (Type A) and alternating injection (Type B). the predicted production indexes were analyzed, the optimal program for half cycle of nitrogen and water injection is 15d for 2 turns, the single well gas injecting rate is 6000 m3/d. the method is used for enhanced recovery of 5.7%.