【作者】 周英芳；

【导师】 王晓冬；

【作者基本信息】 中国地质大学（北京） ， 油气田开发工程， 2010， 硕士

【摘要】 目前普通水驱的驱替动态理论研究比较成熟,很多研究者也在低渗透油藏、多层油藏、聚合物驱油、包含毛管力的三元复合驱理论方面做出了比较有特色的研究,但是其在研究上述问题时在饱和度分布以及驱油效率方面的研究甚少,本文将以以上几个方面为重点研究对象,对各种驱替类型的驱替动态分析方法做比较深入的理论研究。首先在引入启动压力梯度后完成了低渗透油藏的含水率方程、含水饱和度分布以及驱油效率的分析方法。算例表明水油两相启动压力梯度差越大,含水率上升速度变快,前缘饱和度越小,最终驱替效果越差。其次完成了一种计算水驱多层油藏驱替动态的方法,算例分析表明油层渗透率和厚度是影响多层油藏驱替过程的因素。油层渗透率越大,水驱前缘运动速度越快,各油层的驱油效率在水驱前缘突破之前呈线性增长,水驱前缘突破后驱油效率增长很缓;油层厚度对多层油藏各层驱油效率的影响远远不及渗透率对各层驱油效率的影响。第三从Blake-Kozeny方程出发得到幂律型聚合物溶液的表观粘度后,利用一维非牛顿幂律流体驱替牛顿流体得到了变粘度聚合物溶液驱油的含水率特征方程,分析得出聚合物的稠度系数、幂律指数、注入速度、储层物性是影响驱替过程的主要因素。稠度系数增大,驱替液的表观粘度变大,聚合物溶液的含水率增长变慢,原油的无水采收率增大;随着幂律指数增加,聚合物溶液受剪切的作用变弱,聚合物溶液含水率上升变慢,见水时的驱替效率有所增加;驱替速度越大,聚合物越容易剪切变稀,越难形成活塞式驱替,含水率上升的越快,原油的无水采收率越低;物性较差的储层中聚合物驱油的含水率和水驱时的含水率形态很接近,利用聚合物驱并不能显著提高此类油藏的驱油效果。最后利用Foaks模型,分析得到了包含毛管数驱替方程中饱和度、含水率、驱油效率的表达式。分析的除了粘度比、无量纲毛管力是影响整个驱替过程的主要因素。算例分析表明:在粘度比接近于1时,饱和度的变化最剧烈,含水率上升较慢,在相同时间内原油的采出程度最高;毛管力可以弱化前缘饱和度的突变性;注入速度越大,毛管力对驱替过程的影响越小;随着注入时间的增加毛管力的影响越来越小,在驱替后期毛管力的作用。以上的研究成果为各类驱替的动态分析奠定了一定的基础。更多还原

【Abstract】 The theory of 1-D waterflooding performance prediction is mature, however the saturation distribution and displacement efficiency of waterflooding in low permeability reservoir, waterflooding in multilayered reservoirs, polymerflooding and ASPflooding which includes the effect of capillary force are still untouched. Here, we focused on these four types of flooding, analysis their saturation distribution, water cut and displacement efficiency.Firstly, the method to calculate water cut, saturation distribution and displacement efficiency of waterflooding in low permeability reservoir is presented by taking start pressure gradient in to consideration. The case study shows the larger start pressure gradient assumes lower displacement efficiency.Secondly, the model to calculate the displacement efficiency of waterflooding in multilayered reservoirs has been derivate and the case study shows that the factors affect the performance are permeability and height of different layers. The layer with higher permeability assumes better displacement effect. The displacement efficiency of other layers increase lineally before the water breakthrough, which however increase gently after the water breakthrough. The impression of height is not as significant as that of permeability.Thirdly, a novel method was deployed to calculate the displacement efficiency for polymerflooding. This method was based on the improved Blake-Kozeny equation and Buckley-Leverett equation which consider the Non-Newtonian fluid displacement Newtonian fluid. The rheological property of the polymer solution, displacement velocity and the characters of reservoir will dictate the performance of polymerflooding. The case study shows that compared to waterflooding, the water cut slow down and breakthrough recovery improve significantly. Firstly, as consistency coefficient and power law index increases, water cut increasing will be prolonged and breakthrough displacement efficiency improved, however the limited displacement efficiency improved not significant as breakthrough displacement efficiency. Further more, a small velocity always supposes high breakthrough displacement efficiency and slow water cut increasing. And finally polymer flooding is not suitable to improve oil recovery in low permeability reservoirs.Finally, Foaks model is used to establish the displacement equation of waterflooding which includes the effect of capillary force. We conclude that the ration of water viscosity to oil viscosity and no dimensionless capillary force are the key factors that affect the process of ASP flooding. The case study shows the best displacement effect appears when the viscosity equal one. The saturation distribution appears continuity after taking capillary force into consideration. The affect of capillary force appears lower and lower in the process of water injection.The achievement described above can be used to predict the performance of different types of flooding.更多还原