井楼油田氮气辅助蒸汽吞吐机理实验研究

Laboratory study on mechanism of nitrogen-assisted steam stimulation in Jinglou Oilfield

为研究氮气辅助蒸汽吞吐提高采收率的机理,针对井楼油田高浅三区脱气特稠油,利用实验室物理模拟的方法,研究了氮气在开发过程中的作用机理。室内实验结果表明,氮气对高浅三区原油的流动性具有一定改善作用,但降黏效果不明显,其提高采收率的主要机理是:蒸汽吞吐过程中,氮气隔热效果良好,降低了注入蒸汽的热量损失,从而扩大了加热半径;氮气与水的渗流通道并不完全相同,回采过程中可提高洗油效率。注入氮气时宜采用先注入氮气再注入蒸汽的方式,部分氮气在油藏中以微气泡的形式存在,对后续注入蒸汽具有调整吸汽剖面的作用。

In order to investigate the mechanism of nitrogen-assisted steam stimulation, aiming at the dead oil of No.3 Gaoqian Area in Jinglou Oilfield, physical simulation methods are adapted to research the effect of nitrogen on the recovery of steam stimulation. The results show that nitrngen has little effect on the reduction of oil viscosity; the main ,nechanism of enhanced oil recovery is its good heal insulation effect, so the heat loss of injected steam can be reduced anti the heating radius can be increased. Nitrogen anti water have different flow channels. Displacement efficiency can be improved in the process of recovery. The best injection way is injecting nitrogen first and injecting steam last. The nitrogen injected can exist in the way of microbubble anti it has effect of profile control on the following injected steam.