The influence of wettability and shut-in time on oil recovery through microscale simulation based on an ideal model
The influence of wettability and shut-in time on oil recovery through microscale simulation based on an ideal model
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基于理想模型的微观模拟研究润湿性和关井时间对采收率的影响
DOI：
10.1016/j.jngse.2016.10.032
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发表时间：
2017-12
影响因子：
--
通讯作者：
Su, Yunhe
中科院分区：
文献类型：
--
作者：
Li, Aifen;Sun, Hai;Wan, Yujin;Su, Yunhe
在石油开发中，最常用的提高采收率的方法是注水。由于储层中存在不同大小的孔隙，观察到一些有趣的现象。此外，不同润湿性的水驱油效果也不同。关井时间对注水后产量也有影响，但原因尚不清楚。在这项研究中，我们研究了这个问题的格子玻尔兹曼方法在孔隙尺度上，它有很多优点比孔隙网络建模。在理想孔喉模型的基础上，系统地研究了润湿性和关井时间的影响。整个模拟分为注入、关井和排液三个步骤。根据仿真结果，可以得出以下结论。(1)在注入模拟中，随着水润湿性的提高，驱油效率提高，弱润湿条件下所需时间缩短。局部几何结构对入侵顺序有影响。润湿相从孔隙体向孔喉流动时侵入第一孔喉。(2)在关井过程中，关井时间对最终含水饱和度的影响较小，随着关井时间的增加，最终含水饱和度先减小后增大。毛管压力在驱替过程中的反映需要较长的时间，取决于闭端孔隙的数量以及连通闭端孔隙的孔喉直径和长度。流体在大部分孔隙中的运动比较缓慢，在少数封闭孔隙中处于动态平衡状态，且动态平衡只发生在关井初期。(3)在返排阶段，随着润湿性的增加，返排后可获得更高的含水饱和度，从而导致更好的采收率。随着润湿性降低，回流过程需要更多的时间。弱润湿时的返排时间是强润湿时的6倍。高润湿条件下油水分布更集中。剩余油在孔隙体和孔喉中被折断。随着润湿性的降低，剩余油在孔隙空间中呈膜状分布，能够侵入死端孔隙的水减少。通常，随着润湿性增加，可以获得更高的采收率。关井效果需要较长的时间才能反映在驱替效果上，对于致密储层，关井时间更长。
In the oil development, the most common method to enhance recovery is waterflooding. Due to different size of pores existing in reservoirs, some interesting phenomena are observed. In addition, the efficiency of waterflooding is different at different wettability. The shut-in time also has influence on the production rate after water injection while the reason is not clear. In this study, we investigate this problem with lattice Boltzmann method at pore scale, which has many advantages over pore network modeling. The effect of wettability and shut-in time are studied systematically based on an ideal pore-throat model. The whole simulation is divided into three steps: injection, shut-in and flow-back. According to the simulation, the following conclusions can be obtained. (1) In injection simulation, a better efficiency of displacement can be reached as water wettability increases, and it takes less time under weakly wetting situation. The local geometry structure has an impact on invasion order. The wetting phase intrudes into the first pore throat when it flows from pore body to pore throats. (2) In shut-in process, shut-in time has slight influence on the final water saturation, and the water saturation decreases at first, then increases with the shut-in time increasing. It takes more time for capillary pressure to be reflected in the displacement, and it depends on the number of dead end pores and the diameter and length of pore throats that connect the dead end pores. The movement of fluids is quite slow in most pores and is a dynamic balance in a few dead end pores, and the dynamic balance only happens at the beginning of shut-in stage. (3) In flow-back step, as the wettability increases, higher water saturation can be obtained after flow-back process, which leads to a better recovery. The flow-back process takes more time as the wettability decreases. The flow-back time in weakly wetting is six times more than that in highly wetting case. The distribution of oil and water is more concentrated at highly wetting situation. The remaining oil is snapped off in pore body and pore throat. As wettability decreases, the distribution of remaining oil is film-like in the pore space, and less water can invade into the dead end pore. Generally, as the wettability increases, higher recovery can be obtained. It needs take more time for the effect of shut-in to be reflected in the displacement, and even longer time for tight reservoirs.
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影响因子：
--
作者：
Q. Kang;Dongxiao Zhang;Shiyi Chen
通讯作者：
Q. Kang;Dongxiao Zhang;Shiyi Chen
DOI：
--
发表时间：
1971
期刊：
--
影响因子：
--
作者：
F. F. Craig-F.
通讯作者：
F. F. Craig-F.
影响因子：
2.9
作者：
GUNSTENSEN, AK;ROTHMAN, DH;ZANETTI, G
通讯作者：
ZANETTI, G
DOI：
10.2118/10028-ms
发表时间：
1982
期刊：
--
影响因子：
--
作者：
R. Mitchell;P. Bowyer
通讯作者：
R. Mitchell;P. Bowyer
DOI：
10.1103/physreve.70.066135
发表时间：
2004-12
期刊：
Physical review. E, Statistical, nonlinear, and soft matter physics
影响因子：
--
作者：
H. Okabe;M. Blunt
通讯作者：
H. Okabe;M. Blunt