Research and performance evaluation of a temperature-resistant and shear-resistant nano-clean fracturing fluid system

The vigorous development of low-permeability oil and gas reservoirs represents a critical strategy for enhancing hydrocarbon reserves and production in China. Clean fracturing fluid systems are widely recognized as the preferred choice for stimulating low-permeability reservoirs due to their advantages, including low friction resistance, operational convenience, and environmental friendliness. However, conventional clean fracturing fluid systems often exhibit insufficient strength and are unsuitable for medium- to high-temperature reservoirs. To address this limitation, the development of a temperature-resistant clean fracturing fluid system holds significant importance for the efficient fracturing and development of low-permeability oil and gas reservoirs in China. In this study, a novel SiO2 nanoparticle-enhanced temperature-resistant clean fracturing fluid system was investigated. Initially, the primary components of the fracturing fluid, including the type of nanoparticles and their optimal ratios, were systematically screened and determined. The fracturing fluid system was formulated with the following optimal composition: 3.5% alkyl sulfobetaine (AASB-17) + 0.05% SiO2 nanoparticles + 0.6% auxiliary discharging agent + 1% anti-swelling agent. The system's stability and performance were rigorously evaluated through compatibility tests, centrifugation, and other experimental methods, demonstrating excellent stability. Electron microscopy observations revealed that the nanoparticles effectively interconnected surfactant micelles within the solution. The viscoelastic and shear stability properties of the fracturing fluid system were further investigated using a Hacker rheometer. Experimental results indicated that the clean fracturing fluid system achieved a viscosity of 30mPa·s at 70°C. Moreover, the system maintained stable viscosity after 120 minutes of continuous shear at 170 s?¹, confirming its excellent temperature resistance and shear stability. These findings suggest that the developed system is well-suited for meeting the demanding requirements of fracturing operations in challenging reservoir conditions.

Dr. Weidong Wang is mainly engaged in the research and performance testing of fracturing fluid systems. He holds a master's degree in Petroleum and Natural Gas Engineering from China University of Petroleum (East China). He has participated in many national and provincial projects and published numerous articles on fracturing fluid research.