Mohammadi Saber, Hemmat Alimohammad, Afifi Hamidreza, Mahmoudi Alemi Fatemeh
Petroleum Engineering Department, Research Institute of Petroleum Industry (RIPI), Tehran 14665-1998, Iran.
Department of Chemical Engineering, Isfahan University of Technology, Isfahan 84156-83111, Iran.
ACS Omega. 2024 Jun 21;9(26):28676-28690. doi: 10.1021/acsomega.4c03000. eCollection 2024 Jul 2.
The use of nanotechnology in the field of acidizing, particularly in fracturing fluids, has garnered significant attention over the past decade. Viscoelastic surfactants (VESs) are utilized as one of the most effective fracturing fluids, possessing both elasticity and viscosity properties. These fluids are crucial additives in acidizing packages, enhancing their performance. However, various factors, such as salinity, temperature, pressure, and concentration, can sometimes weaken the efficacy of these fluids. To address this, the integration of nanoparticles has been explored to improve fluid retention in reservoirs and enhance the efficiency. This study focuses on investigating the impact of the main metallic-type nanoparticles on the rheological behavior of VES fluids. Iron oxide, magnesium oxide, and zinc oxide nanoparticles were utilized, and the microscopic-scale rheological behavior of the fluids was thoroughly evaluated. The highest performance for enhancing fluid gelation, stability, and rheological characteristics of VES fluids was found for FeO nanoparticles at an optimum concentration of 500 ppm. At this concentration and shear rate of 100 s, the viscosity of the fluid reached 169.61 cP. For iron oxide nanoparticles at a concentration of 500 ppm, by increasing the temperature from 25 to 85 °C, the gelation state of the fluid increased from 7 h and 50 min to 17 h and 45 min. This improvement is attributed to their high surface area and the increased density of entanglement points within the micelles, leading to a more interconnected structure with enhanced viscoelastic properties. Furthermore, iron oxide nanoparticles significantly enhance gelation by physically connecting the micelles, thereby improving stability and structure. The absorption of surfactant molecules by the nanoparticles additionally contributes to micelle reconstruction and shape alteration. The presence of iron oxide nanoparticles helps maintain the gel structure even at elevated temperatures, preventing rapid viscosity decrease. Our findings may provide new insights for development of high-performance, economical, and environment-friendly fracturing fluids used in well stimulation operations.
在过去十年中，纳米技术在酸化领域，尤其是压裂液中的应用受到了广泛关注。粘弹性表面活性剂（VESs）被用作最有效的压裂液之一，兼具弹性和粘性特性。这些流体是酸化配方中的关键添加剂，可提高其性能。然而，盐度、温度、压力和浓度等各种因素有时会削弱这些流体的功效。为解决这一问题，人们探索了纳米颗粒的整合，以提高储层中的流体滞留率并提高效率。本研究重点调查了主要金属型纳米颗粒对VES流体流变行为的影响。使用了氧化铁、氧化镁和氧化锌纳米颗粒，并对流体的微观尺度流变行为进行了全面评估。发现当FeO纳米颗粒的最佳浓度为500 ppm时，在增强VES流体的凝胶化、稳定性和流变特性方面表现出最高性能。在此浓度和100 s的剪切速率下，流体的粘度达到169.61 cP。对于浓度为500 ppm的氧化铁纳米颗粒，将温度从25℃提高到85℃，流体的凝胶化状态从7小时50分钟增加到17小时45分钟。这种改善归因于它们的高表面积以及胶束内缠结点密度的增加，导致形成具有增强粘弹性特性的更相互连接的结构。此外，氧化铁纳米颗粒通过物理连接胶束显著增强凝胶化，从而提高稳定性和结构。纳米颗粒对表面活性剂分子的吸收还有助于胶束重构和形状改变。即使在高温下，氧化铁纳米颗粒的存在也有助于维持凝胶结构，防止粘度迅速下降。我们的研究结果可能为开发用于油井增产作业的高性能、经济且环保的压裂液提供新的见解。
