低渗透油藏不同流动单元并联水驱油

为了描述低渗透油藏多层合注合采时，各层水驱效果差异、流体流动特征及分布规律，开展了不同流动单元并联水驱油实验及数值模拟研究。以新疆宝浪油田宝北区块低渗透储层为例，按流动层段指标由大到小将储层划分为五类流动单元，选取其中三类流动单元的9块天然岩心与1块人造岩心，组成4组并联模型，进行了水驱油实验及数值模拟研究。实验结果表明：不同流动单元岩心并联组合后，物性好的流动单元驱油效率比单独驱替时要高、物性差的流动单元驱油效率比单独驱替时要低；不同流动单元之间渗透率级差越大，流动单元之间相互影响越强烈，驱油效率相互差值越大。

Water displacing oil efficiency with cores grouped in parallel of different flow units in low-permeability reservoirs

We studied differences in the water displacing oil efficiency of individual layers,fluid flow characteristics and liquid distributions during the multi-layer injection and production of low-permeability reservoirs using water displacing oil experiments with cores grouped in parallel and numerical simulation.The Baobei block of the Baolang oilfield,Xinjiang,was taken as an example,where low-permeability reservoirs were divided into five types of flow units according to flow zone indices in descending order.Nine natural cores selected from three types of the above-mentioned five flow units plus one artificial core were employed to combine four experimental groups in parallel,and each of them was performed with water displacing oil experiments.Also four numerical models corresponding to these four groups were simulated.The results showed that after the parallel combination of different flow units,the flow unit with good physical property had the water displacing oil efficiency higher than the flow unit that was displaced separately,while the water displacing oil efficiency of the flow unit with poor physical property was lower than that of the flow unit that was displaced separately.Therefore,the bigger the permeability differential of different flow units and the stronger the mutual effect between individual flow units,the greater the mutual differential of the water displacing oil efficiency.