Abstract

The major challenges in using nanoparticles in oil and gas industry projects are high investment costs and environmental problems. Bio-nanoparticles provide a solution to environmental and economic challenges in the nano-assisted EOR processes. In this work, the potential of natural calcium carbonate nanoparticles containing chitin for wettability alteration in enhanced oil recovery was studied. The adsorption behavior of bio-nanoparticles onto calcite-dolomite rock surface was distinguished through kinetics, equilibrium, and thermodynamics assessments. Besides, oil recovery is measured through forced imbibition experiments. The Taguchi experimental design was conducted to optimize the parameters influencing oil recovery factor in forced imbibition experiments, including nanofluid concentration, temperature, and oil type. Results of the adsorption experiment showed that adsorption kinetics of bio-Ca nanoparticles onto calcite-dolomite surface follows the pseudo-second-order model and monolayer, Langmuir adsorption of bio-nanoparticles. The endothermic heat of physical adsorption (physisorption) was found 3.32 kJ/mol. Based on the experimental design, the optimum parameters that can rise to additional oil displacement are a nanofluid concentration of 0.05 wt.%, normal heptane as liquid phase, minimum salinity (Milli-Q-water), and ambient temperature. The oil recovery factor increased by 17.52% at an optimum nanofluid concentration of 0.05 wt.% in comparison to a base fluid without nanoparticle. The results indicate that synthesized bio-Ca nanoparticles have proper EOR potential in both light oil and heavy oil reservoirs at certain conditions.

摘要

在石油和天然气工业项目中使用纳米颗粒的主要挑战是高投资成本和环境问题。生物纳米颗粒为纳米辅助 EOR 过程中的环境和经济挑战提供了解决方案。在这项工作中，研究了含有几丁质的天然碳酸钙纳米粒子在提高石油采收率中改变润湿性的潜力。通过动力学、平衡和热力学评估来区分生物纳米颗粒在方解石-白云石岩石表面的吸附行为。此外，采油率是通过强制渗吸实验测量的。进行田口实验设计以优化影响强制渗吸实验中石油采收率的参数，包括纳米流体浓度、温度和油类型。吸附实验结果表明，生物钙纳米颗粒在方解石-白云石表面的吸附动力学遵循拟二级模型和生物纳米颗粒的单层朗缪尔吸附。发现物理吸附（物理吸附）的吸热为 3.32 kJ/mol。根据实验设计，可以增加额外驱油的最佳参数是纳米流体浓度为 0.05 wt.%、正庚烷为液相、最小盐度（Milli-Q-水）和环境温度。与不含纳米颗粒的基液相比，在 0.05 wt.% 的最佳纳米流体浓度下，石油采收率提高了 17.52%。结果表明，合成的生物钙纳米颗粒在一定条件下在轻油和重油油藏中均具有适当的 EOR 潜力。