姬塬长2油层渗流特征和驱油效率影响因素分析

Analysis on Seepage Characteristics and Influencing Factors of Oil Displacement Efficiency of Chang 2 Reservoir in Jiyuan Oilfield

选取模型进行真实砂岩水驱油实验,对姬塬油田元214区长2油层的微观储层渗流特征和驱油效率的影响因素进行分析研究。实验结果表明,研究区的微观水驱油驱替类型主要有均匀、网状与指状3种类型,并且3种驱替类型对应模型的驱油效率依次降低。残余油存在的形式主要是以油膜残余油和绕流残余油分布为主,比较少见卡断残余油和角隅残余油。通过实验分析驱替效率的影响因素,储层物性是最主要的因素;其次非均质性和微观孔隙结构对驱油效率也有一定影响;同时在一定的压力范围内,提高注水压力可以明显的提高驱油效率,但是当压力增大到一定程度后,水流容易形成优势通道,导致注入水只是沿着优势通道向前推进,驱油效率的增加幅度就会逐渐减小。综合研究分析,应用上述水驱油实验得出的结论可以为油藏的开发研究提供可靠的依据。

According water- flooding experiments with the real sandstone micro- model,this article mainly study on the micro- water driving oil percolation characteristics of reservoir,and the influence factors of oil displacement efficiency of Chang 2 reservoir in Jiyuan oilfield Yuan 214 for its tableland oilfield. The results show that micro water driving oil displacement type of the study area mainly has three types： homogeneous,reticular and finger. Oil displacement efficiency of homogeneous,reticular and finger decreased systematically. Residual oil distribution are mainly residual oil film and residual oil flow around（ by- pass oil）,pore edge and corner residual oil and card off residual oil are few. Physical property is the primary factor that affecting the effects of reservoir oil displacement. In certain pressure range,oil displacement efficiency can be increased effectively by increasing driving water pressure.However,when the pressure increases to a certain degree,the flow more easily to form dominant flow channels and driving water along with the dominant channel,which lead to increasing amplitude of the displacement efficiency becoming smaller. Microscopic pore structure and heterogeneity also influence oil displacement efficiency. Comprehensive analysis shows that the application of the above conclusion can be a reliable basis for reservoir development.