Microscopic flow simulation of viscoelastic fluid based on interface tracking method
Microscopic flow simulation of viscoelastic fluid based on interface tracking method
复制标题
基于界面跟踪法的粘弹性流体微观流动模拟
DOI：
10.1360/n972016-00050
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发表时间：
2016-10
影响因子：
--
通讯作者：
Li, Aifen
中科院分区：
文献类型：
--
作者：
Yao, Jun;Sun, Hai;Zhang, Lei;Li, Aifen
水驱后储层微观剩余油可分为油膜型、死角型、孔喉型和油簇型四种类型。当粘性力不足以克服水驱毛管力时，油被困在孔喉中。终端中的油受到岩石结构的限制。油团主要存在于孔隙介质的低渗透区，受毛管力和岩石结构的制约。特别是在高含水期，水驱油效率极低。近年来，粘弹性流体驱（聚合物驱）技术在石油工业中得到广泛应用，以提高水驱后的采收率，驱油效率得到了很大的提高。然而，对粘弹性流体驱油的认识不足制约了其进一步发展。粘弹性流体如何调动剩余油的研究是必要的。本文采用直接数值模拟方法对微通道内的两相流进行了数值模拟。粘弹性效应使用Oldrophil-B流变模型进行模拟。用相场法确定了两种不互溶流体的界面位置。该模型结合了多孔介质的润湿条件。研究了在水驱和粘弹性流体驱替条件下盲端油膜和剩余油的动态变化规律。分析了微通道中油膜的受力情况，指出了微通道中油膜运动变形与水驱油过程不同的原因。此外，还观察和比较了水和粘弹性流体在盲端的波及效率。引入无因次速度的概念作为盲端的扫掠边界，解释了水和粘弹性流体采收率的差异。用于模拟的数值解是使用有限元方法进行的。最后，以Oldrophil-B流体绕流两平行平板间圆柱为例，验证了模型和解的正确性。与水相比，粘弹性流体更容易调动残余油，可以大大提高驱油效率。粘弹性流体的粘度不是唯一的一个机制的油膜的流动;“弹性”的流体是另一个关键的驱动机制，这是反映了韦森伯格数。粘弹性流体作用在残余油膜上的水平应力差远大于水作用在残余油膜上的水平应力差。粘弹性流体引起的法向应力分布不均匀，导致残余油膜发生显著变形。黏弹性流体可以大大提高盲端的波及效率，这种现象在亲水油藏中更为明显。黏弹性流体在盲端的波及边界比水的波及边界深，这解释了黏弹性流体驱时盲端剩余油较少的原因。该研究为三次采油提供了有效的指导。
Microscopic residual oil in reservoirs after water flooding can be classified into four types: oil films, oil in the dead end, oil in pores throat, and oil clusters. The oil is trapped in pores throat when the viscous force is not sufficiently large to overcome the capillary forces with water flooding. The oil in the dead end is constrained by the rock configuration. The oil clusters mainly exist in the lower permeability portion of the porous media, which is constrained by the capillary force and rock configuration. In particular, the efficiency of water flooding is extremely low at the high water cut period. Recently, viscoelastic fluid flooding (polymer flooding) was widely applied to improve the recovery after water flooding in the petroleum industry, and the displacement efficiency was greatly improved. However, the poor understanding of viscoelastic fluid flooding restricts its further progress. The investigation of how the viscoelastic fluid mobilizes the residual oil is warranted. In this study, a direct numerical simulation method is employed to simulate immiscible two-phase flows in a micro channel. Viscoelastic effects are simulated using the Oldroyd-B rheological model. The position of the interface between two immiscible fluids is determined by using the phase field method. The model incorporates the wetting condition of the porous media. The dynamics of oil film and residual oil in the dead end are explored under the displacement of water and viscoelastic fluid. The forces exerting on the oil film in the micro channel are analyzed, which contribute to the difference of oil film movement and deformation between the water flooding process and viscoelastic fluid process. Moreover, the sweep efficiencies of water and viscoelastic fluid in the dead end are observed and compared. The concept of dimensionless velocity is introduced as the sweep boundary in the dead end to explain the discrepancy of recovery between water and viscoelastic fluid. The numerical solution used for the simulation is performed using a finite element method. Additionally, a benchmark of the flow of Oldroyd-B fluid past a cylinder between two parallel plates is given to validate the correction of the model and solution. Compared with water, viscoelastic fluid can more easily mobilize the residual oil which can greatly improve the displacement efficiency. The viscosity is not the only one mechanism of the viscoelastic fluid’s mobilization of the oil film; ‘elasticity’ of the fluid is another key driving mechanism which is reflected by the Weissenberg number. The horizontal stress difference of viscoelastic fluid acting on the residual oil film is considerably larger than that of water. The uneven distribution of normal stress caused by the viscoelastic fluid leads the residual oil film to deform significantly. Viscoelastic fluid can greatly improve the sweep efficiency in the dead end and this phenomenon is more obvious in the water-wet reservoir. The sweep boundary of viscoelastic fluid in the dead end is deeper than that of water which explain the reason why less residual oil trapped in the dead end with viscoelastic fluid flooding. The study provides effective guidance for tertiary oil recovery.
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DOI：
--
发表时间：
2011
期刊：
Journal of Southwest Petroleum University
影响因子：
--
作者：
Liu Li-li
通讯作者：
Liu Li-li
影响因子：
--
作者：
Z. Lei;Kang QinJun;Yao Jun;G. Ying;S. Hai
通讯作者：
Z. Lei;Kang QinJun;Yao Jun;G. Ying;S. Hai
DOI：
--
发表时间：
2007
期刊：
Journal of China University of Petroleum
影响因子：
--
作者：
Liu Chun-ze
通讯作者：
Liu Chun-ze
影响因子：
3.1
作者：
Harvie, D. J. E.;Cooper-White, J. J.;Davidson, M. R.
通讯作者：
Davidson, M. R.
影响因子：
4.1
作者：
Yue, Pengtao;Zhou, Chunfeng;Hu, Howard H.
通讯作者：
Hu, Howard H.