Development and Performance Evaluation of a Novel Silica Nanoparticle-Reinforced CO₂-Sensitive Fracturing Fluid with High Temperature and Shear Resistance Ability

Abstract

In order to further increase the temperature and shear resistance of a conventional CO2-sensitive clean fracturing fluid, a novel silica nanoparticle-reinforced CO2-sensitive fracturing fluid system was developed. The system was prepared with the compositions of 2.0 wt % N-[3-(dimethylamino) propyl] oleamide, 1.5 wt % sodium p-toluene sulfonate (NaPts), and 0.025 wt % silica nanoparticles. The rheological properties, temperature resistance, shear resistance, sand-carrying capacity, gel-breaking property, and core damage property of the system were systematically studied and evaluated. Compared with the conventional CO2-sensitive fracturing fluid system, the silica nanoparticle-reinforced CO2-sensitive fracturing fluid system has a better viscosity increase effect, and the zero-shear viscosity increases from 2900 to 3500 mPa·s. By adding and removing CO2, the viscosity of the system can be repeatedly converted from high to low, and the reusable property can be realized. After introducing silica nanoparticles, the temperature resistance ability of the clean fracturing fluid increases from 100 to 130 °C, the sand-carrying effect increases by 23%, rapid and thorough gel breaking occurs, and core damage is less than 13%. We expect that this study can broaden the application of the CO2-sensitive clean fracturing fluid in low permeability, high-temperature reservoirs and provide a theoretical basis for field applications.

Review on High-Temperature-Resistant Viscoelastic Surfactant Fracturing Fluids: State-of-the-Art and Perspectives

“…It is of much importance that the addition of nanoparticles can significantly increase the viscosity of WLM fluid at high temperatures, because high temperature will cause the shortening of micelles, so as to provide more micelle end-caps to participate in the crosslinking with nanoparticles. 245,309 Silicon dioxide (SiO 2 ) 294,310 and metal oxides (magnesium oxide (MgO), 304 iron oxide (Fe 2 O 3 ), 311 zinc oxide (ZnO), 1 0 3 , 2 5 7 , 3 1 2 , 3 1 3 alumina (Al 2 O 3 ), 3 0 1 zirconia (ZrO 2 ), 314,315 and titanium oxide (TiO 2 ) 232,276 ) are commonly used nanoparticles to improve the temperature resistance for a fracturing fluid because they have higher reactivity and efficiency. 292 The interaction between nanoparticles and WLMs is affected by various parameters, including the type, size, and concentration of nanoparticles, surfactant concentration, temperature, and charge on surfactants and nanoparticles.…”

“…292 Similarly, Gurluk et al 248 reported that the VES fluids (2−4 vol % amidoamine oxide surfactant + 0.072 wt % NPs) enhanced with MgO-NPs maintained a viscosity greater than 100 mPa•s for 6 h, while the solutions prepared with ZnO maintained a viscosity greater than 20 mPa•s for 6 h. The results indicated that the interaction between MgO particles and the surfactants is stronger than that between ZnO particles and the surfactants, bringing about a stronger network and an increase in viscosity. Liu et al 294 found that there are optimal surfactant concentrations, counterion salt concentrations, and nanosilica concentrations for the enhanced VES system with nanosilica. In the CTAB system, Nettesheim et al 306 and Helgeson et al 305 showed that increasing the concentration of NPs enhances the viscosity and elasticity of the solution.…”

“…Silicon dioxide (SiO 2 ) , and metal oxides (magnesium oxide (MgO), iron oxide (Fe 2 O 3 ), zinc oxide (ZnO), ,,, alumina (Al 2 O 3 ), zirconia (ZrO 2 ), , and titanium oxide (TiO 2 ) , ) are commonly used nanoparticles to improve the temperature resistance for a fracturing fluid because they have higher reactivity and efficiency . The interaction between nanoparticles and WLMs is affected by various parameters, including the type, size, and concentration of nanoparticles, surfactant concentration, temperature, and charge on surfactants and nanoparticles. ,, Therefore, in order to select the preferred high-temperature-resistant nano-enhanced VES fracturing fluid, these parameters need to be optimized.…”

“…Often chemical modification of nanomaterials can effectively improve their performances. Nanomaterials, without the external response characteristics, are easy to be trapped in the pores of the rock, causing potential damage to the formation. − For example, the nanosilica-enhanced CO 2 -sensitive fracturing fluid system prepared by Liu et al showed an increase in core-damage rate from 8.16% to 12.46% and an increase in residue content from 0.1 to 0.4 mg/L, compared to the system without nanosilica. Similarly, the titanium dioxide NP enhanced VES fracturing fluid system prepared by Zhou et al showed a 9% increase in damage rate compared to the system without NPs (from 13.59% to 14.83%).…”

“…Due to the pseudocross-linking of NPs and WLMs, the elastic modulus of the VES fluid is increased and its suspension performance is enhanced. , A follow-up study by Huang et al also demonstrated the wall-building performance of the NP-based systems, and the retained permeability of the system was 100%. Liu et al prepared a silica nanoparticle-reinforced CO 2 -sensitive fracturing fluid system. After the introduction of the silica NPs, the temperature resistance of the VES fracturing fluid increased from 100 to 130 °C, and the sand-carrying ability increased by 23%.…”