Study of surface complexation modeling on a novel hybrid enhanced oil recovery (EOR) method; smart-water assisted foam-flooding
Study of surface complexation modeling on a novel hybrid enhanced oil recovery (EOR) method; smart-water assisted foam-flooding
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DOI：
10.1016/j.petrol.2020.107563
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发表时间：
2020-12
影响因子：
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通讯作者：
A. Hassan;M. Ayoub;M. Eissa;H. Bruining;P. Zitha
中科院分区：
文献类型：
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作者：
A. Hassan;M. Ayoub;M. Eissa;H. Bruining;P. Zitha
这方面的贡献集中在方解石-盐水-表面活性剂系统中的表面络合物。当使用新的混合强化采油（EOR）方法时，这与采油有关，该方法结合了智能水（即，离子改性的盐水）和在碳酸盐中高压下用溶解的二氧化碳（CO2）对轻质油进行泡沫驱油（SWAF）（即，方解石）储层。使用这种新的混合EOR方法（即，SWAF工艺）不仅在经济上有吸引力（即，它降低了运营成本），而且还提高了生产过程的效率，从而减少了对环境的影响。离子改性盐水（即，低盐度）具有双重改善效果。它不仅导致更稳定的泡沫层状结构，而且还有助于改变碳酸盐岩的润湿性，在某些条件下导致更有利的相对渗透率行为。在离子改性盐水存在下的改性渗透率行为的机理仅部分被理解。因此，我们最初在零维（热力学）设置中研究该过程，该设置可用于一维（1D）置换过程，其中含有二氧化碳（CO2）的油相和含有二氧化碳（CO2）和所有离子物质的水相。使用DLVO理论和表面络合模型来更好地理解离子改性盐水作为润湿性改进剂和泡沫稳定剂的机理。我们使用（NaCl）和（MgCl 2）进行模拟，以显示二价离子在高盐度（8500 mmol/kg-w）和低盐度（0.4 mmol/kg-w）下对环境条件（25°C）和水环境条件（80°C）的影响。我们将我们的分析局限于使用表面复合物的Dzombak-Morel模型的描述，该模型基于Debye-Hückel理论（即，直到0.3（摩尔/千克水）的离子强度有效）。我们还研究了二氧化碳（CO2）对低盐度泡沫层稳定性的影响。我们对泡沫层进行了建模，其中含有水相中的（阳离子）表面活性剂作为表面复合物。我们使用PHREEQC软件来计算表面电荷和表面电势。二氧化碳（CO2）相的存在导致四价C（IV）化合物在水膜中溶解。PHREEQC还计算平衡浓度和表面电位，并允许研究盐度和二氧化碳（CO2）气体压力的影响。对于二氧化碳（CO2）气氛中的皂膜（泡沫膜），我们使用Pitzer活度系数（即，有效值高达6（mol/kg水））。由于我们的目的是显示这种方法的方法和多功能性，我们为将来的工作留下了这些参数的更现实的选择。对于所考虑的条件，我们可以定性地说，在（NaCl，即，pH > 10）和（MgCl 2即，pH > 10.3）时，低盐度情况下（25°C）和（80° C）的水膜行为比高盐度情况下（25 ° C）和（80 °C）的水膜行为更稳定。此外，高的二氧化碳（CO2）压力对膜具有不稳定的影响，因为它们降低了表面电位。降低的表面电位导致减少的静电双层排斥，从而使泡沫膜不稳定，而低盐度导致表面电位的屏蔽减少，从而提高泡沫膜的稳定性。低矿化度渗流的特点是高残余油饱和度和低的油水两相渗流端点渗透率。这导致更有利的迁移率比，从而导致更有利的置换过程。对于方解石表面，增强的稳定性有助于稳定水...
This contribution focuses on surface complexes in the calcite-brine-surfactant system. This is relevant for the recovery of oil when using a new hybrid enhanced oil recovery (EOR) method, which combines smart-water (i.e., ionically modified brine) and foam-flooding (SWAF) of light oil with dissolved carbon dioxide (CO2) at high pressure in carbonate (i.e., calcite) reservoirs. Using this new hybrid EOR-method (i.e., the SWAF-process) is not only economically attractive (i.e., it reduces opex costs) but also enhances the effectiveness of the production process, and thus reduces the environmental impact. Ionically modified brine (i.e., low-salinity) has a dual improvement effect. It not only leads to more stable foam lamellae, but also helps to change the carbonate rock wettability, leading for some conditions to more favorable relative permeability behavior. The mechanism for the modified permeability behavior in the presence of ionically modified brine is only partly understood. Therefore, we study this process initially in a zero dimensional (thermodynamics) setting, which can be used for the one dimensional (1D) displacement process with an oleic phase that contains carbon dioxide (CO2) and an aqueous phase that contains both carbon dioxide (CO2) and all the ionic substances. Using DLVO theory and surface complexation modeling to better understand the mechanism(s) of ionically modified brine as wettability modifier and foam stabilizer. We perform simulations using both (NaCl) and (MgCl2) to show the effect of a divalent ion at the high-salinity (8500 mmol/kg-w) and low-salinity (0.4 mmol/kg-w) for both ambient-conditions at (25°C) and at the reservoir-conditions (80°C). We confine our analysis to a description that uses the Dzombak-Morel model of surface complexes, which is based on the Debye-Hückel theory (i.e., valid up to ionic strength of 0.3 (mol/kilogram of water)). We also investigate the effect of carbon dioxide (CO2) on the stability of low-salinity foam-laminae. We model the foam-laminae, which contain as surface complex a (cationic) surfactant in an aqueous phase. We use the PHREEQC-software to calculate the surface charge and the surface potential. The presence of a carbon dioxide (CO2) phase leads to dissolution of four valent C(IV) compounds in the aqueous film. PHREEQC also calculates the equilibrium concentrations and surface potential and allows the study of the effect of salinity and the carbon dioxide (CO2) gas pressure. For the soap-film (foam-film) in a carbon dioxide (CO2) atmosphere we do use Pitzer activity coefficients (i.e., valid up to 6 (mol/kilogram of water)). As our aim is to show the methodology and the versatility of this approach, we leave more realistic choices of these parameters for future work.sFor the conditions considered we can qualitatively state that, in the presence of (NaCl i.e., at pH > 10) and (MgCl2i.e., pH > 10.3), the low-salinity case shows a more stable water-film behavior at (25°C) and at (80°C) than the high-salinity case for both (25°C) and (80°C). Moreover, high carbon dioxide (CO2) pressures have a destabilizing effect on the film, as they reduce the surface potential. A reduced surface potential leads to a decreasing electrostatic double layer repulsion and thus destabilizes the foam-film, whereas low-salinity leads to less screening of the surface potential and thus improves the stability of the foam-film. The low-salinity flow is characterized by a high residual oil saturation and low end-point permeability for the two phase oil-water flow. This leads to a more favorable mobility ratio and thus a more favorable displacement process. For the calcite surface an enhanced stability helps to stabilize the water …