不同韵律油藏蒸汽驱后转热水驱物理模拟研究

Physical Simulation on Thermal Water Flooding After Steam Flooding in Different Rhythm Heavy Oil Reservoir

针对普通稠油油藏,利用三维剖面模型分别进行反韵律、正韵律和复合韵律油藏注蒸汽开发,后期进行转热水驱或水汽交替注入开发的物理模拟研究。结果表明,注入蒸汽由于重力超覆作用而向油藏顶部运移,和正韵律油藏相比,反韵律油藏顶部更容易形成蒸汽的窜流通道;而转热水驱或水汽交替注入后,注入热水携带油藏中蒸汽的剩余热量向油藏下部运移,从而有效动用油藏中蒸汽驱的剩余油,改善稠油油藏的开发效果,降低生产井的含水率。蒸汽驱后转水汽交替注入的驱油效率比转热水驱的驱油效率有所提高,水汽交替注入实施过程中含水率出现大幅度降低,增油效果明显。

Aiming at conventional heavy oil reservoir,3-D dimensional cross-section model was employed to study thermal water flooding or water-steam alternative injection after steam flooding in anti-rhythm reservoir,positive rhythm reservoir and composite rhythm reservoir.The results show that steam trended to flow on the top of reservoir due to over lap of injection steam.Steam channeling is more easily generated in anti-rhythm reservoir than in positive rhythm reservoir.Thermal water flooding and water-steam alternative injection after steam flooding could carry remaining heat to migrate into the bottom of reservoir,so amount of heavy oil in reservoir can be recovered.The recovery efficiency of water-steam alternative injection is obviously higher than thermal water flooding and water cut decreased largely during water-steam alternative injection.