【作者】 李宾飞；

【导师】 李兆敏；

【作者基本信息】 中国石油大学 ， 油气田开发工程， 2007， 博士

【摘要】 氮气泡沫调驱是非均质油藏开发中后期提高采收率的有效途径,近年来进行了一系列研究和现场试验,但在泡沫渗流机理、影响因素分析以及适应性评价方面还有待深入研究,是一种处于发展阶段的三次采油技术。因此,进一步完善氮气泡沫调驱技术,对其适应性进行系统分析,对于提高氮气泡沫调驱应用水平具有重要作用。论文根据氮气泡沫渗流机理,提出将反映起泡剂起泡能力和稳定性的综合性能的泡沫综合值作为主要参数,用于氮气泡沫调驱用起泡剂的筛选。通过室内实验,对油田常用起泡剂性能进行了评价,并进行了影响因素分析。系统研究了气液比、含油饱和度、渗透率对氮气泡沫渗流规律的影响,结果表明,含油饱和度是影响氮气泡沫渗流阻力的最主要因素,泡沫渗流阻力随着含油饱和度的升高而降低,剩余油分布规律决定了调驱过程中氮气泡沫的渗流规律,受此影响,地层非均质性的增加对泡沫调剖效果的影响较小。对比研究了氮气泡沫调驱、聚合物驱和强化氮气泡沫调驱三种提高采收率方法的驱油特征。同聚合物驱相比,氮气泡沫调驱和强化氮气泡沫调驱具有更强的流度调节能力,更有利于提高波及体积,而聚合物驱更有利于提高高渗岩心中的采收率;强化氮气泡沫调驱比氮气泡沫调驱更有利于提高高渗岩心的采收率。同时分析了泡沫渗流对地层出砂的影响,与水相比,泡沫对砂粒的携带能力大得多,除粘度差别因素外,由于泡沫在出口处的膨胀而产生的助排作用是更为主要的因素。采用毛细管束模型分析了H-B流体的渗流规律以及各参数的影响;在此基础上,对氮气泡沫的非线性渗流规律和调驱过程进行了分析计算,得到了与实验变化趋势相一致的结果;并提出,对于氮气泡沫调驱存在一个最优注入压力,在该压力下氮气泡沫调驱提高采收率的幅度达到最大。最后采用数值模拟方法,分析了油藏条件和生产因素对氮气泡沫调驱效果的影响,表明氮气泡沫调驱更适合应用于正韵律、层间连通性较好的非均质油藏。更多还原

【Abstract】 Profile control and flooding technology of nitrogen foam is an effective improved oil recovery method for heterogeneous reservior at the later stage of development, and a series of studies and field experiments has been done in recent years. But it is at development stage and needs deep study in mechanisms of foam flow in porous media, influential factor and applicability. Therefore, it is important for improving application effects to develop the profile control and flooding technology of nitrogen foam and analyze its applicability. Based on the mechanisms of foam flow in porous media, a new parameter of foam comprehensive value was employed to evaluate foamers, which denoted the comprehensive characteristic of foamer’s foaming ability and stability. Several foamers used in oil field were evaluated through experiment. The effects of gas-liquid ratio, oil saturation and permeability on nitrogen foam flow law in porous media were studied systemly. Oil saturation is the main influential factor of foam’s fluidity, and just for this, the aggravation of formation heterogeneity has little effect on the effect of the profile control, foam’s flow law is decided by remaining oil distribution. And the application effects of profile control and flooding technology of nitrogen foam, polymer flooding and enhanced profile control and flooding technology of nitrogen foam were evaluated. Profile control and flooding technology of nitrogen foam and enhanced profile control and flooding technology of nitrogen foam are more effective than polymer flooding in harmonizing mobility and improving sweep volume, but the later is more effective in improving oil recovery of high permibility core. The enhanced profile control and flooding technology of nitrogen foam is more effective than the profile control and flooding technology of nitrogen foam in improving oil recovery of high permibility core. The effects of foam flow on sand production were studied in the paper. Foam has stronger ability of carrying sands than water, not only because of high viscosity but also because of the expansion of foam at the outlet. The capillary bundle model was employed to study the flow law and its influential factor of Herschel-Bulkley fluid in porous media. And based on this, the foam’s nonlinear flow was studied, and the results can be used to explain the results of experiments, and there is an optmum injection pressure for profile control and flooding technology of nitrogen foam to get maximum recovery ratio. The effects of reservoir conditions and production factors on profile control and flooding technology of nitrogen foam were studied through numerical simulation, the results show that the technology is more suitable for the heterogeneous reservoir of positive rhythm, good connectedness.更多还原