Direct pore-scale reactive transport modelling of dynamic wettability changes induced by surface complexation
Direct pore-scale reactive transport modelling of dynamic wettability changes induced by surface complexation
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DOI：
10.1016/j.advwatres.2017.10.032
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发表时间：
2018
影响因子：
4.7
通讯作者：
J. Maes;S. Geiger
中科院分区：
文献类型：
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作者：
J. Maes;S. Geiger
实验室实验表明，通过控制注入水的组成（例如，通过降低离子强度），可以显著增加通过注水从砂岩和碳酸盐岩储层的石油产量。最近的研究表明，表面电荷的变化引起的润湿性的变化可能是所谓的低盐度效应的驱动机制之一。在这种情况下，在低离子强度下的水驱过程中，油采收率的潜在增加将受到孔隙尺度上的流动、运输和化学反应之间的相互关系的强烈影响。因此，基于Navier-Stokes方程的直接数值模拟和表面络合模型，建立了一个包括两相流动、溶质反应输运和润湿性改变的新数值模型。我们的模型首次被用来匹配实验结果的油滴脱离粘土补丁。然后，我们研究了润湿性变化对简单二维方解石微观模型孔隙尺度位移的影响，并评估了水成分和注入速度等几个参数的影响。最后，我们重复模拟实验上的一个更大，更复杂的孔隙几何形状代表碳酸盐岩。我们的模拟突出了低盐度对碳酸盐岩产油的两种不同影响：侵入后留在孔隙中的油团数量较少，侵入的孔隙数量较多。
Laboratory experiments have shown that oil production from sandstone and carbonate reservoirs by waterflooding could be significantly increased by manipulating the composition of the injected water (e.g. by lowering the ionic strength). Recent studies suggest that a change of wettability induced by a change in surface charge is likely to be one of the driving mechanism of the so-called low-salinity effect. In this case, the potential increase of oil recovery during waterflooding at low ionic strength would be strongly impacted by the inter-relations between flow, transport and chemical reaction at the pore-scale. Hence, a new numerical model that includes two-phase flow, solute reactive transport and wettability alteration is implemented based on the Direct Numerical Simulation of the Navier–Stokes equations and surface complexation modelling. Our model is first used to match experimental results of oil droplet detachment from clay patches. We then study the effect of wettability change on the pore-scale displacement for simple 2D calcite micro-models and evaluate the impact of several parameters such as water composition and injected velocity. Finally, we repeat the simulation experiments on a larger and more complex pore geometry representing a carbonate rock. Our simulations highlight two different effects of low-salinity on oil production from carbonate rocks: a smaller number of oil clusters left in the pores after invasion, and a greater number of pores invaded.