Si Xiaodong, Luo Mingliang, Li Mingzhong, Ma Yuben, Huang Yige, Pu Jingyang
School of Petroleum Engineering, China University of Petroleum (East China), Qingdao 266580, China.
Key Laboratory of Unconventional Oil and Gas Development, China University of Petroleum (East China), Ministry of Education, Qingdao 266580, China.
Nanomaterials (Basel). 2022 Feb 28;12(5):812. doi: 10.3390/nano12050812.
FeO@ZnO nanocomposites (NCs) were synthesized to improve the stability of the wormlike micelle (WLM) network structure of viscoelastic surfactant (VES) fracturing fluid and were characterized by Fourier transform infrared spectrometry (FT-IR), scanning electron microscopy (SEM), energy dispersive spectrometry (EDS), X-ray diffraction (XRD) and vibrating sample magnetometry (VSM). Then, an NC-enhanced viscoelastic surfactant solution as a fracturing fluid (NC-VES) was prepared, and its properties, including settlement stability, interactions between NCs and WLMs, proppant-transporting performance and gel-breaking properties, were systematically studied. More importantly, the influences of the NC concentration, shear rate, temperature and pH level on the stability of NC-VES were systematically investigated. The experimental results show that the NC-VES with a suitable content of NCs (0.1 wt.%) shows superior stability at 95 °C or at a high shear rate. Meanwhile, the NC-VES has an acceptable wide pH stability range of 6-9. In addition, the NC-VES possesses good sand-carrying performance and gel-breaking properties, while the NCs can be easily separated and recycled by applying a magnetic field. The temperature-resistant, stable and environmentally friendly fracturing fluid opens an opportunity for the future hydraulic fracturing of unconventional reservoirs.
合成了FeO@ZnO纳米复合材料(NCs)以提高粘弹性表面活性剂(VES)压裂液的蠕虫状胶束(WLM)网络结构的稳定性,并通过傅里叶变换红外光谱(FT-IR)、扫描电子显微镜(SEM)、能谱(EDS)、X射线衍射(XRD)和振动样品磁强计(VSM)对其进行了表征。然后,制备了一种作为压裂液的NC增强型粘弹性表面活性剂溶液(NC-VES),并系统研究了其性能,包括沉降稳定性、NCs与WLMs之间的相互作用、支撑剂输送性能和破胶性能。更重要的是,系统研究了NC浓度、剪切速率、温度和pH值对NC-VES稳定性的影响。实验结果表明,含有合适含量NCs(0.1 wt.%)的NC-VES在95℃或高剪切速率下表现出优异的稳定性。同时,NC-VES具有6-9的可接受的宽pH稳定性范围。此外,NC-VES具有良好的携砂性能和破胶性能,而通过施加磁场可以很容易地分离和回收NCs。这种耐高温、稳定且环保的压裂液为未来非常规油藏的水力压裂开辟了机遇。